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Note: This page contains sample records for the topic "tropical convection observed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

Properties of tropical convection observed by ARM millimeter-radars  

NLE Websites -- All DOE Office Websites (Extended Search)

Properties of tropical convection observed by ARM millimeter-radars Properties of tropical convection observed by ARM millimeter-radars Haynes, John Colorado State University Stephens, Graeme Colorado State University Category: Cloud Properties The results of an analysis of tropical cloud systems observed from a variety of vertically pointing radar systems are described. In particular, observations taken during five years of operation of the ARM millimeter wavelength radar system (MMCR) at Manus Island in the Tropical West Pacific region are characterized into cloud classes according to the radar reflectivity structures of these cloud systems, associated rainfall, and surface radiative properties. These observations of cloud properties are composited with respect to various phases of the Madden Julian Oscillation, which is a dominant mode of variability at Manus Island. A method of better

2

Physical Characterization of Tropical Oceanic Convection Observed in KWAJEX  

Science Journals Connector (OSTI)

The Tropical Rainfall Measuring Mission (TRMM) Kwajalein Experiment (KWAJEX) was designed to obtain an empirical physical characterization of precipitating convective clouds over the tropical ocean. Coordinated datasets were collected by three ...

Sandra E. Yuter; Robert A. Houze Jr.; Eric A. Smith; Thomas T. Wilheit; Edward Zipser

2005-04-01T23:59:59.000Z

3

Passive microwave observations of mesoscale convective systems over the tropical Pacific Ocean  

E-Print Network (OSTI)

This paper presents high resolution passive microwave measurements obtained in the western Pacific warm pool region. These measurements represent the first comprehensive observations of convection over the tropical oceans, and were obtained from...

McGaughey, Gary Rae

2012-06-07T23:59:59.000Z

4

REGIONAL VARIABILITY IN TROPICAL CONVECTION: OBSERVATIONS FROM TRMM  

E-Print Network (OSTI)

and longitude. The reflectivity histograms and ice water contents were then combined with LIS lightning flash structure histograms, and lightning flash density data reveal that 1) relative to tropical continental characteristics of precipitation vertical structure and associated lightning flash density. In general

Rutledge, Steven

5

Mesoscale disturbances in the tropical stratosphere excited by convection: Observations and effects on the stratospheric momentum budget  

SciTech Connect

The importance of the momentum flux of topographically generated mesoscale gravity waves to the extratropical middle atmosphere circulation has been well established for over a decade. Estimates of the zonal forcing due to tropical mesoscale gravity waves, however, are hampered by lack of data on their primarily convective sources. The advent of aircraft measurements over tropical convective systems now makes such estimates possible without the use of ad hoc assumptions about amplitudes and phase speeds. Aircraft measurements from NASA's 1980 Panama and 1987 STEP/Australia Missions show that convectively generated disturbances observed just above the tropopause have horizontal scales comparable to those of the underlying anvils (about 50--100 km) with peak-to-peak isentropic surface variations of about 300--400 m. Satellite imagery of tropical anvil evolution indicates a typical lifetime of about five hours. Assuming that each convective system's impact on the stratosphere can be modeled as a time-dependent [open quotes]mountain[close quotes] with the preceding spatial and time scales, the excited spectrum of gravity waves can be calculated. A suitable quasi-linear wave-mean flow interaction parameterization and satellite-derived cloud area statistics can then be used to evaluate the zonal acceleration as a function of altitude induced by gravity waves from mesoscale convective systems. The results indicate maximum westerly accelerations due to breaking mesoscale gravity waves of almost 0.4 m s[sup [minus]1]/day in the upper stratosphere (in the region of the semiannual oscillation) during September, comparable to but probably smaller than the accelerations induced by planetary-scale Kelvin waves. Calculated easterly accelerations due to breaking mesoscale gravity waves in the QBO region below 35 km are smaller, accounting for about 10% of the required zonal acceleration. 35 refs., 14 figs., 1 tab.

Pfister, L.; Scott, S.; Loewenstein, M. (NASA/Ames Research Center, Moffett Field, CA (United States)); Bowen, S. (San Jose State Univ., CA (United States)); Legg, M. (Synernet, Fremont, CA (United States))

1993-04-15T23:59:59.000Z

6

ARM - Field Campaign - Year of Tropical Convection (YOTC)  

NLE Websites -- All DOE Office Websites (Extended Search)

govCampaignsYear of Tropical Convection (YOTC) govCampaignsYear of Tropical Convection (YOTC) Campaign Links Year of Tropical Convection Website Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Year of Tropical Convection (YOTC) 2008.05.01 - 2010.04.30 Lead Scientist : Sally McFarlane Description Example of a sonde profile available from the ARM Archive The realistic representation of tropical convection in global atmospheric models is a long-standing challenge for weather and global climate models. The lack of fundamental knowledge in this area causes difficulties in modeling and predicting prominent phenomena of the tropical atmosphere such as the inter-tropical convergence zone (ITCZ), El-Nino/Southern Oscillation (ENSO), monsoons, the Madden-Julian Oscillation (MJO), tropical cyclones,

7

Mesoscale Convective Systems in Relation to African and Tropical Easterly Jets  

Science Journals Connector (OSTI)

This paper documents the interaction processes between mesoscale convective systems (MCS), the tropical easterly jet (TEJ), and the African easterly jet (AEJ) over West Africa during the monsoon peak of 2006 observed during the African Monsoon ...

L. Besson; Y. Lemaître

2014-09-01T23:59:59.000Z

8

Patterns of Convection in the Tropical Western Pacific  

NLE Websites -- All DOE Office Websites (Extended Search)

Patterns of Convection in the Tropical Western Pacific Patterns of Convection in the Tropical Western Pacific J. H. Mather Pacific Northwest National Laboratory Richland, Washington Introduction Convection is ubiquitous throughout the maritime continent region. However, the frequency of convec- tion is not uniform. While much of this region does not experience seasons to the same degree as one finds in mid-latitudes, the annual cycle of the sun's passage does have a large impact on convection throughout the maritime continent and the tropical western Pacific. The distribution of islands also affects convection in a variety of ways. Atmospheric Radiation Measurement (ARM) Program has three sites in the Tropical Western Pacific (TWP) region, illustrated in Figure 1. The sites are located on Manus, Nauru, and at Darwin, Australia.

9

Limiting Factors for Convective Cloud Top Height in the Tropics  

NLE Websites -- All DOE Office Websites (Extended Search)

Limiting Factors for Convective Cloud Top Limiting Factors for Convective Cloud Top Height in the Tropics M. P. Jensen and A. D. Del Genio National Aeronautics and Space Administration Goddard Institute for Space Studies Columbia University New York, New York Introduction Populations of tropical convective clouds are mainly comprised of three types: shallow trade cumulus, mid-level cumulus congestus and deep convective clouds (Johnson et al. 1999). Each of these cloud types has different impacts on the local radiation and water budgets. For climate model applications it is therefore important to understand the factors which determine the type of convective cloud that will occur. In this study, we concentrate on describing the factors that limit the cloud-top heights of mid-

10

Do the Tallest Convective Cells over the Tropical Ocean Have Slow Updrafts?  

Science Journals Connector (OSTI)

Far from continents, a few storms lift precipitation-size ice particles into the stratosphere, 17 to 18 km above the tropical ocean. This study is the first to examine the observed properties of a large sample of these extremely tall convective ...

Owen A. Kelley; John Stout; Michael Summers; Edward J. Zipser

2010-05-01T23:59:59.000Z

11

Title: Radar-observed convective characteristics during TWP-ICE  

NLE Websites -- All DOE Office Websites (Extended Search)

Title: Radar-observed convective characteristics during TWP-ICE Title: Radar-observed convective characteristics during TWP-ICE Schumacher, Courtney Texas A&M University Houze, Robert University of Washington May, Peter Bureau or Meteorology Research Centre Frederick, Kaycee Cetrone, Jasmine Vallgren, Andreas Category: Field Campaigns This poster will describe the radar dataset obtained in the Tropical Warm Pool International Cloud Experiment (TWP-ICE), which is to take place 20 January - 14 February 2006 in the vicinity of Darwin, Australia. We will describe the convective systems observed during the project by two scanning C-band Doppler radars, one of which will provide dual-polarization measurements, and ARM's vertically pointing cloud radar and lidar installations. In addition, we will discuss the potential for combining

12

Environment and the Lifetime of Tropical Deep Convection in a Cloud-Permitting Regional Model Simulation  

SciTech Connect

By applying a cloud tracking algorithm to tropical convective systems simulated by a regional high resolution model, the study documents environmental conditions before and after convective systems are initiated over ocean and land by following them during their lifetime. The comparative roles of various environmental fields in affecting the lifetime of convection are also quantified. The statistics of lifetime, maximum area, propagation speed and direction of the simulated deep convection agrees well with geostationary satellite observations. Over ocean, convective systems enhance surface fluxes through the associated wind gusts as well as cooling and drying of the boundary layer. A significant relationship is found between the mean surface fluxes during their lifetime and the longevity of the systems which in turn is related to the initial intensity of the moist updraft and to a lesser extent upper level shear. Over land, on the other hand, convective activity suppresses surface fluxes through cloud cover and the lifetime of convection is related to the upper level shear during their lifetime and strength of the heat fluxes several hours before the initiation of convection. For systems of equal lifetime, those over land are significantly more intense than those over ocean especially during early stages of their lifetime.

Hagos, Samson M.; Feng, Zhe; McFarlane, Sally A.; Leung, Lai-Yung R.

2013-08-01T23:59:59.000Z

13

Observations on Buoyant Convection in Reverse Osmosis  

Science Journals Connector (OSTI)

Observations on Buoyant Convection in Reverse Osmosis ... Buoyancy Effects in Dead-End Reverse Osmosis:? Visualization by Holographic Interferometry ... Buoyancy Effects in Dead-End Reverse Osmosis:? Visualization by Holographic Interferometry ...

Terry J. Hendricks; Jean F. Macquin; Forman A. Williams

1972-05-01T23:59:59.000Z

14

Final Technical Report for "Radiative Heating Associated with Tropical Convective Cloud Systems: Its Importance at Meso and Global Scales"  

SciTech Connect

Heating associated with tropical cloud systems drive the global circulation. The overall research objectives of this project were to i) further quantify and understand the importance of heating in tropical convective cloud systems with innovative observational techniques, and ii) use global models to determine the large-scale circulation response to variability in tropical heating profiles, including anvil and cirrus cloud radiative forcing. The innovative observational techniques used a diversity of radar systems to create a climatology of vertical velocities associated with the full tropical convective cloud spectrum along with a dissection of the of the total heating profile of tropical cloud systems into separate components (i.e., the latent, radiative, and eddy sensible heating). These properties were used to validate storm-scale and global climate models (GCMs) and were further used to force two different types of GCMs (one with and one without interactive physics). While radiative heating was shown to account for about 20% of the total heating and did not have a strong direct response on the global circulation, the indirect response was important via its impact on convection, esp. in how radiative heating impacts the tilt of heating associated with the Madden-Julian Oscillation (MJO), a phenomenon that accounts for most tropical intraseasonal variability. This work shows strong promise in determining the sensitivity of climate models and climate processes to heating variations associated with cloud systems.

Schumacher, Courtney

2012-12-13T23:59:59.000Z

15

Sensitivity of Tropical Cyclones to Parameterized Convection in the NASA GEOS5 Model  

Science Journals Connector (OSTI)

The sensitivity of tropical cyclones (TCs) to changes in parameterized convection is investigated to improve the simulation of TCs in the North Atlantic. Specifically, the impact of reducing the influence of the Relaxed Arakawa-Schubert (RAS) ...

Young-Kwon Lim; Siegfried D. Schubert; Oreste Reale; Myong-In Lee; Andrea M. Molod; Max J. Suarez

16

Tropical Cyclogenesis Sensitivity to Environmental Parameters in Radiative-Convective Equilibrium  

E-Print Network (OSTI)

In this study, the relationship between the likelihood of tropical cyclogenesis and external environmental forcings is explored in the simplest idealized modelling framework possible: radiative-convective equilibrium on a ...

Nolan, David S.

17

Feature-Point Detection Using Distance Transforms: Application to Tracking Tropical Convective Complexes  

Science Journals Connector (OSTI)

The identification, tracking, and statistical analysis of tropical convective complexes using satellite imagery is explored in the context of identifying feature points suitable for tracking. The feature points are determined based on the shape ...

K. I. Hodges

1998-03-01T23:59:59.000Z

18

Impact of Convective Organization on the Response of Tropical Precipitation Extremes to Warming  

E-Print Network (OSTI)

Impact of Convective Organization on the Response of Tropical Precipitation Extremes to Warming extremes to warming in organized convection is ex- amined using a cloud-resolving model. Vertical shear, the fractional increase of precipitation extremes is similar to that of surface water vapor, which

Paris-Sud XI, Université de

19

A numerical study of mesoscale convection in a rotating tropical atmosphere  

E-Print Network (OSTI)

similar to the profile of a tropical disturbance. The meso-p forcing of convection consisted of' seven temperature perturbations con- fined below 2. 4 km at intervals of 8 km out to 60 km. The meso-9 forcing of convection comprised of a cosine thermal... perturbation field out to 75 km. Two different classes of simulations were performed. The first part explored how background vorticity affects convection generated by meso-7 and meso-9 forcing. The second part investigated how meso-9 forcing of convection...

Fitzpatrick, Patrick James

1992-01-01T23:59:59.000Z

20

Lightning flash rate and chemistry simulation of tropical island convection using a cloud-resolved model  

E-Print Network (OSTI)

Lightning flash rate and chemistry simulation of tropical island convection using a cloud schemes (FRPSs) and estimating the average NO production per lightning flash in this unique storm type network (LINET) provided lightning flash data for the model and a lightning placement scheme injected

Maryland at College Park, University of

Note: This page contains sample records for the topic "tropical convection observed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Influence of Sea Surface Temperature on Humidity and Temperature in the Outflow of Tropical Deep Convection  

E-Print Network (OSTI)

-Service Aircraft (MOZAIC) project are analyzed in the vicinity of deep convective outflow to study the variationsInfluence of Sea Surface Temperature on Humidity and Temperature in the Outflow of Tropical Deep upper-tropospheric temperature and humidity by the Mea- surement of Ozone and Water Vapor by Airbus In

Johnson, Richard H.

22

Squall Lines and Convectively Coupled Gravity Waves in the Tropics: Why Do Most Cloud Systems Propagate Westward?  

Science Journals Connector (OSTI)

The coupling between tropical convection and zonally propagating gravity waves is assessed through Fourier analysis of high-resolution (3-hourly, 0.5°) satellite rainfall data. Results show the familiar enhancement in power along the dispersion ...

Stefan N. Tulich; George N. Kiladis

2012-10-01T23:59:59.000Z

23

Mesoscale Structure of Trade Wind Convection over Puerto Rico: Composite Observations and Numerical Simulation  

Science Journals Connector (OSTI)

We examine the mesoscale structure of the atmospheric boundary layer (ABL), low-level circulation, and trade wind convection over the sub-tropical island of Puerto Rico in mid-summer. Shallow afternoon thunder...

Mark R. Jury; Sen Chiao; Eric W. Harmsen

2009-08-01T23:59:59.000Z

24

Role of Diurnal Warm Layers in the Diurnal Cycle of Convection over the Tropical Indian Ocean during MISMO  

Science Journals Connector (OSTI)

The role of air–sea interaction in the diurnal variations of convective activity during the suppressed and developing stages of an intraseasonal convective event is analyzed using in situ observations from the Mirai Indian Ocean cruise for the ...

H. Bellenger; Y. N. Takayabu; T. Ushiyama; K. Yoneyama

2010-06-01T23:59:59.000Z

25

The Effects of Explicit versus Parameterized Convection on the MJO in a Large-Domain High-Resolution Tropical Case Study. Part I: Characterization of Large-Scale Organization and Propagation  

Science Journals Connector (OSTI)

High-resolution simulations over a large tropical domain (~20°S–20°N, 42°E–180°) using both explicit and parameterized convection are analyzed and compared to observations during a 10-day case study of an active Madden–Julian oscillation (MJO) ...

Christopher E. Holloway; Steven J. Woolnough; Grenville M. S. Lister

2013-05-01T23:59:59.000Z

26

October 1986 R. H. Johnson 721 Lower-Tropospheric Warming and Drying in Tropical Mesoscale Convective Systems  

E-Print Network (OSTI)

October 1986 R. H. Johnson 721 Lower-Tropospheric Warming and Drying in Tropical Mesoscale Convective Systems: Implications for the Problem of Cumulus Parameterization By Richard H. Johnson Department beneath the stratiform com- ponents of these systems (Houze, 1977; Zipser, 1977; Johnson and Kriete, 1982

Johnson, Richard H.

27

RETRIEVAL OF HYDROMETEOR PROFILES IN TROPICAL CYCLONES AND CONVECTION BY A COMBINED  

E-Print Network (OSTI)

to simulate the ice phase radiative transfer process more reasonably. Final optimal 's as well as the observed a significant influence on the energy and water budgets. The latent heat release in tropical cyclones provides of the circulation of the storm. Directly related to latent heating, ice water content (IWC) and liq

Jiang, Haiyan

28

Tracking tropical cloud systems - Observations for the diagnosis of simulations by the Weather Research and Forecasting (WRF) Model  

SciTech Connect

To aid in improving model parameterizations of clouds and convection, we examine the capability of models, using explicit convection, to simulate the life cycle of tropical cloud systems in the vicinity of the ARM Tropical Western Pacific sites. The cloud life cycle is determined using a satellite cloud tracking algorithm (Boer and Ramanathan, 1997), and the statistics are compared to those of simulations using the Weather Research and Forecasting (WRF) Model. Using New York Blue, a Blue Gene/L supercomputer that is co-operated by Brookhaven and Stony Brook, simulations are run at a resolution comparable to the observations. Initial results suggest a computational paradox where, even though the size of the simulated systems are about half of that observed, their longevities are still similar. The explanation for this seeming incongruity will be explored.

Vogelmann, A.M.; Lin, W.; Cialella, A.; Luke, E.; Jensen, M.; Zhang, M.

2010-03-15T23:59:59.000Z

29

Cloud system resolving model simulations of tropical cloud systems observed during the Tropical  

E-Print Network (OSTI)

the Weather Research and Forecasting (WRF) model. The WRF model is configured with a highest-resolving domain convection. The second regime is a monsoon break, which contains intense localized systems that are rep-based observational systems including a polarimetric weather radar, cloud radar, wind profilers, radi- ation

Jakob, Christian

30

Relationships between tropical cyclone intensity and satellite based indicators of inner core convection: 85 GHz ice scattering signature and lightning  

E-Print Network (OSTI)

indirectly, using satellite-borne observations of the scattering of upwelling microwave radiation by precipitation sized ice and satellite-borne observations of lightning. The observations are then compared to tropical cyclone intensity and the resulting...

Cecil, Daniel Joseph

2012-06-07T23:59:59.000Z

31

The Three-Dimensional Morphology of Simulated and Observed Convective Storms over Southern England  

Science Journals Connector (OSTI)

A set of high-resolution radar observations of convective storms has been collected to evaluate such storms in the Met Office Unified Model during the Dynamical and Microphysical Evolution of Convective Storms (DYMECS) project. The 3-GHz ...

Thorwald H. M. Stein; Robin J. Hogan; Kirsty E. Hanley; John C. Nicol; Humphrey W. Lean; Robert S. Plant; Peter A. Clark; Carol E. Halliwell

2014-09-01T23:59:59.000Z

32

Vertical profiles of radar reflectivity of convective cells in tropical and mid-latitude mesoscale convective systems  

E-Print Network (OSTI)

of tropical oceanic and tropical continental MCSs during the monsoon wet seasons of 1987/1988 and 1988/1989. The atmospheric structure, particularly the CAPE and low level vertical wind shear for all the MCS events studied is analyzed to help... lectivity, at a height of 1. 9 km, of the 68 72 2 December 1988 tropical monsoon case at 0542 LT . . 74 36 37 38 As in Fig. 35, except at 0609 LT Time series of zonal wind and CAPE at Darwin during the 1988/1989 monsoon wet season. Contour plot...

Lutz, Kurt Reed

2012-06-07T23:59:59.000Z

33

A census of precipitation features in the tropics using TRMM: radar, ice scattering, and lightning observations  

E-Print Network (OSTI)

The observation of precipitation in the tropics has been greatly enhanced trough the launch of the Tropical Rainfall Measuring Mission (TRMM) satellite n 1997. TRMM'S ability to continuously and simultaneously observe precipitation processes...

Nesbitt, Stephen William

1999-01-01T23:59:59.000Z

34

Impact of Aerosols on Tropical Cyclones: An Investigation Using Convection-permitting Model Simulation  

SciTech Connect

The role of aerosols effect on two tropical cyclones over Bay of Bengal are investigated using a convection permitting model with two-moment mixed-phase bulk cloud microphysics scheme. The simulation results show the role of aerosol on the microphysical and dynamical properties of cloud and bring out the change in efficiency of the clouds in producing precipitation. The tracks of the TCs are hardly affected by the changing aerosol types, but the intensity exhibits significant sensitivity due to the change in aerosol contribution. It is also clearly seen from the analyses that higher heating in the middle troposphere within the cyclone center is in response to latent heat release as a consequence of greater graupel formation. Greater heating in the middle level is particularly noticeable for the clean aerosol regime which causes enhanced divergence in the upper level which, in turn, forces the lower level convergence. As a result, the cleaner aerosol perturbation is more unstable within the cyclone core and produces a more intense cyclone as compared to other two perturbations of aerosol. All these studies show the robustness of the concept of TC weakening by storm ingestion of high concentrations of CCN. The consistency of these model results gives us confidence in stating there is a high probability that ingestion of high CCN concentrations in a TC will lead to weakening of the storm but has little impact on storm direction. Moreover, as pollution is increasing over the Indian sub-continent, this study suggests pollution may be weakening TCs over the Bay of Bengal.

Hazra, Anupam; Mukhopadhyay, P.; Taraphdar, Sourav; Chen, J. P.; Cotton, William R.

2013-07-16T23:59:59.000Z

35

Observation of moisture tendencies related to shallow convection  

Science Journals Connector (OSTI)

Tropospheric moisture is a key factor controlling the global climate and its variability. For instance, moistening of the lower troposphere is necessary to trigger the convective phase of a Madden-Julian Oscillation. However, the relative ...

H. Bellenger; K. Yoneyama; M. Katsumata; T. Nishizawa; K. Yasunaga; R. Shirooka

36

Evaluation of Trigger Functions for Convective Parameterization Schemes Using Observations  

Science Journals Connector (OSTI)

Realistic simulation of different modes of atmospheric variability ranging from diurnal cycle to interannual variation in global climate models (GCMs) depends crucially on the convection trigger criteria. In this study, using the data from ...

E. Suhas; Guang J. Zhang

2014-10-01T23:59:59.000Z

37

Improving Convection Parameterization Using ARM Observations and NCAR Community Atmosphere Model  

SciTech Connect

Highlight of Accomplishments: We made significant contribution to the ASR program in this funding cycle by better representing convective processes in GCMs based on knowledge gained from analysis of ARM/ASR observations. In addition, our work led to a much improved understanding of the interaction among aerosol, convection, clouds and climate in GCMs.

Zhang, Guang J [Scripps Institution of Oceanography

2013-07-29T23:59:59.000Z

38

Role of Convective Entrainment in Spatial Distributions of and Temporal Variations in Precipitation over Tropical Oceans  

Science Journals Connector (OSTI)

The authors demonstrate that an appropriate treatment of convective entrainment is essential for determining spatial distributions of and temporal variations in precipitation. Four numerical experiments are performed using atmospheric models with ...

Nagio Hirota; Yukari N. Takayabu; Masahiro Watanabe; Masahide Kimoto; Minoru Chikira

2014-12-01T23:59:59.000Z

39

A Multisatellite Investigation of the Convective Properties of Developing and Nondeveloping Tropical Disturbances  

Science Journals Connector (OSTI)

A comprehensive passive microwave satellite dataset is analyzed to quantify and compare the time evolution of convective properties of the pregenesis stage of developing disturbances (12 cases) and nondeveloping disturbances (3 cases), to ...

Jonathan Zawislak; Edward J. Zipser

2014-12-01T23:59:59.000Z

40

Aircraft Observations of Convective Systems in the Indian Ocean [EVS Event]  

NLE Websites -- All DOE Office Websites (Extended Search)

Aircraft Observations of Convective Systems in the Indian Ocean Aircraft Observations of Convective Systems in the Indian Ocean August 23, 2013 Speaker: Bradley Nicholas Guy National Research Council Postdoctoral Fellow NOAA National Severe Storms Laboratory Date: Friday, August 23, 2013 Time: 11:00 a.m. Location: Argonne National Laboratory TCS Building 240 Room 4301 In the DYNAMO (Dynamics of the Madden-Julian Oscillation) field experiment, a large number of measurement platforms were deployed to study environmental and convective cloud system characteristics of the Madden-Julian Oscillation (MJO) initiation region in the Indian Ocean. A mobile platform, the NOAA P-3 instrumented aircraft, sampled intense convective cloud systems, along with the surrounding environment. This presentation will explore the characteristics of mesoscale convective

Note: This page contains sample records for the topic "tropical convection observed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

A Test of the Simulation of Tropical Convective Cloudiness by a Cloud-Resolving Model MARIO A. LOPEZ, DENNIS L. HARTMANN, PETER N. BLOSSEY, ROBERT WOOD,  

E-Print Network (OSTI)

un- certainties in projections of future climates (Bony et al. 2006; Solomon et al. 2007). Clouds solar radiation, although their effect on the net energy balance is often much less than with intense tropical convective systems are known to have long lifetimes and to cover large areas, accounting

Hartmann, Dennis

42

Measurements of Saharan Dust in Convective Clouds over the Tropical Eastern Atlantic Ocean  

Science Journals Connector (OSTI)

Mineral dust particles have been shown to act as cloud condensation nuclei, and they are known to interact with developing tropical storms over the Atlantic downwind of the Sahara. Once present within liquid droplets, they have the potential to ...

Cynthia H. Twohy

43

Convective Coupling and Interannual and Intraseasonal Coupled Variabilities in the Tropics  

Science Journals Connector (OSTI)

Recent analyses point at close structural similarities and intimate dynamical connections among the members of a wide spectrum of variabilities in the global Tropics. This suggests that these oscillations with widely different timescales may have ...

P. Goswami; Rameshan K.

2000-08-01T23:59:59.000Z

44

Constructing a Merged Cloud-Precipitation Radar Dataset for Tropical Convective Clouds during the DYNAMO/AMIE Experiment at Addu Atoll  

SciTech Connect

To improve understanding of the convective processes key to the Madden-Julian-Oscillation (MJO) initiation, the Dynamics of the MJO (DYNAMO) and Atmospheric Radiation Measurement MJO Investigation Experiment (AMIE) collected four months of observations from three radars, the S-band Polarization Radar (S-Pol), the C-band Shared Mobile Atmospheric Research & Teaching Radar (SMART-R), and Ka-band Zenith Radar (KAZR) on Addu Atoll in the tropical Indian Ocean. This study compares the measurements from the S-Pol and SMART-R to those from the more sensitive KAZR in order to characterize the hydrometeor detection capabilities of the two scanning precipitation radars. Frequency comparisons for precipitating convective clouds and non-precipitating high clouds agree much better than non-precipitating low clouds for both scanning radars due to issues in ground clutter. On average, SMART-R underestimates convective and high cloud tops by 0.3 to 1.1 km, while S-Pol underestimates cloud tops by less than 0.4 km for these cloud types. S-Pol shows excellent dynamic range in detecting various types of clouds and therefore its data are well suited for characterizing the evolution of the 3D cloud structures, complementing the profiling KAZR measurements. For detecting non-precipitating low clouds and thin cirrus clouds, KAZR remains the most reliable instrument. However, KAZR is attenuated in heavy precipitation and underestimates cloud top height due to rainfall attenuation 4.3% of the time during DYNAMO/AMIE. An empirical method to correct the KAZR cloud top heights is described, and a merged radar dataset is produced to provide improved cloud boundary estimates, microphysics and radiative heating retrievals.

Feng, Zhe; McFarlane, Sally A.; Schumacher, Courtney; Ellis, Scott; Comstock, Jennifer M.; Bharadwaj, Nitin

2014-05-16T23:59:59.000Z

45

The Tilt of the Leading Edge of Mesoscale Tropical Convective Lines  

Science Journals Connector (OSTI)

The tilt with height of the leading edge of seven mesoscale convective lines in GATE is determined by two independent methods. When averaged over time and along the line axis, the tilt is found to he surprisingly shallow, between 20 and 35 ...

M. A. LeMone; G. M. Barnes; E. J. Szoke; E. J. Zipser

1984-03-01T23:59:59.000Z

46

Characteristics of Precipitating Convective Systems Accounting for the Summer Rainfall of Tropical and Subtropical South America  

E-Print Network (OSTI)

and Subtropical South America ULRIKE ROMATSCHKE AND ROBERT A. HOUZE JR. University of Washington, Seattle of the precipitating cloud systems that account for the summer rainfall of tropical and subtropical South America role in the meteorology, climatology, and hydrology of South America. They not only produce

Houze Jr., Robert A.

47

The World Wide Lightning Location Network and Convective Activity in Tropical Cyclones  

E-Print Network (OSTI)

February 2010, in final form 19 August 2010) ABSTRACT Lightning flash density in tropical cyclones (TCs) is investigated to identify whether lightning flashes provide information on TC intensity and/or intensity change. The National Lightning Detection Network is used to analyze flash density as a function of peak current

Corbosiero, Kristen L.

48

Seasonal cycles of O3, CO, and convective outflow at the tropical tropopause  

E-Print Network (OSTI)

gas species. There is a significant seasonal cycle in ozone (O3) at the tropical tropopause, both a radiative transfer model [Fu and Liou, 1992]. This was done at 10 ozone- sonde stations from the SHADOZ network (Southern Hemisphere Additional Ozonesonde ozonesonde stations [Thompson et al., 2003a, 2003b

Thompson, Anne

49

Observed Rainfall Asymmetry in Tropical Cyclones Making Landfall over China  

Science Journals Connector (OSTI)

In this study, the rainfall asymmetries in tropical cyclones (TCs) that made landfall in Hainan (HN), Guangdong (GD), Fujian (FJ), Zhejiang (ZJ) Provinces of Mainland China and Taiwan (TW) from 2001 to 2009 were analyzed based on the TRMM ...

Zifeng Yu; Yuqing Wang; Haiming Xu

50

Intermediate Zonal Jets in the Tropical Pacific Ocean Observed by Argo Floats* SOPHIE CRAVATTE  

E-Print Network (OSTI)

Intermediate Zonal Jets in the Tropical Pacific Ocean Observed by Argo Floats* SOPHIE CRAVATTE´veloppement, LEGOS, Toulouse, France WILLIAM S. KESSLER National Oceanic and Atmospheric Administration/Pacific Argo float data in the tropical Pacific Ocean during January 2003­August 2011 are analyzed to obtain

Boyer, Edmond

51

Quantitative Differences between Lightning and Nonlightning Convective Rainfall Events as Observed with Polarimetric Radar and MSG Satellite Data  

Science Journals Connector (OSTI)

To increase understanding of the relationships between lightning and nonlightning convective storms, lightning observations from the National Aeronautics and Space Administration (NASA) African Monsoon Multidisciplinary Analyses (NAMMA) campaign ...

Retha Matthee; John R. Mecikalski; Lawrence D. Carey; Phillip M. Bitzer

2014-10-01T23:59:59.000Z

52

Mixed-phase clouds, thin cirrus clouds, and OLR over the tropics: observations, retrievals, and radiative impacts  

E-Print Network (OSTI)

of clouds are formed by deep convection and convergence of water vapor. Thus, it is very important to understand the radiative energy balance of the tropics and the effect of clouds on the radiation field. For mixed-phase clouds, error analyses pertaining...

Lee, Joonsuk

2009-06-02T23:59:59.000Z

53

Photo: Bruno Marty / IRD Observed and expected changes to the tropical  

E-Print Network (OSTI)

simulations 104 3.2 Features of the tropical Pacific Ocean 105 3.2.1 Large-scale currents 105 3.2.2 Ocean.3 Observed and projected changes in the tropical Pacific Ocean 141 3.3.1 Large-scale currents 141 3.3.2 Ocean, dissolved oxygen concentration and pH affect biological activity; and oceanic currents, waves and sea level

Qiu, Bo

54

Thermodynamic fluctuations in solar photospheric three-dimensional convection simulations and observations  

E-Print Network (OSTI)

Numerical 3D radiative (M)HD simulations of solar convection are used to understand the physical properties of the solar photosphere. To validate this approach, it is important to check that no excessive thermodynamic fluctuations arise as a consequence of the partially incomplete treatment of radiative transfer. We investigate the realism of 3D convection simulations carried out with the Stagger code. We compared the characteristic properties of several spectral lines in solar disc centre observations with spectra synthesized from the simulations. We degraded the synthetic spectra to the spatial resolution of the observations using the continuum intensity distribution. We estimated the necessary spectral degradation by comparing atlas spectra with averaged observed spectra. In addition to deriving a set of line parameters directly, we used the SIR code to invert the spectra. Most of the line parameters from the observational data are matched well by the degraded simulation spectra. The inversions predict a m...

Beck, C; Moreno-Insertis, F; Puschmann, K G; Rezaei, R

2013-01-01T23:59:59.000Z

55

Sensitivity of tropical deep convection in global models: effects of horizontal resolution, surface constraints and 3D atmospheric nudging  

E-Print Network (OSTI)

, the Eastern Indian Ocean and Maritime Continent, and 174 tropical South America. The Inter Tropical Convergence Zone (ITCZ), and to a smaller extent the 175 South Pacific Convergence Zone (SPCZ), also have their signatures in the OLR and PR fields. When 176... larger for PR. This is 161 in agreement with previous studies, which show large model precipitation biases in tropical ocean 162 regions (Martin et al., 2010; Schiemann et al., 2014). For OLR ~85% of model configurations are in 163 good agreement...

Chemel, Charles; Russo, Maria; Hosking, Scott; Telford, Paul; Pyle, John

2014-01-01T23:59:59.000Z

56

Utilizing CLASIC observations and multiscale models to study the impact of improved Land surface representation on modeling cloud- convection  

SciTech Connect

The CLASIC experiment was conducted over the US southern great plains (SGP) in June 2007 with an objective to lead an enhanced understanding of the cumulus convection particularly as it relates to land surface conditions. This project was design to help assist with understanding the overall improvement of land atmosphere convection initiation representation of which is important for global and regional models. The study helped address one of the critical documented deficiency in the models central to the ARM objectives for cumulus convection initiation and particularly under summer time conditions. This project was guided by the scientific question building on the CLASIC theme questions: What is the effect of improved land surface representation on the ability of coupled models to simulate cumulus and convection initiation? The focus was on the US Southern Great Plains region. Since the CLASIC period was anomalously wet the strategy has been to use other periods and domains to develop the comparative assessment for the CLASIC data period, and to understand the mechanisms of the anomalous wet conditions on the tropical systems and convection over land. The data periods include the IHOP 2002 field experiment that was over roughly same domain as the CLASIC in the SGP, and some of the DOE funded Ameriflux datasets.

Niyogi, Devdutta S. [Purdue

2013-06-07T23:59:59.000Z

57

The Tropical Response to Extratropical Thermal Forcing in an Idealized GCM: The Importance of Radiative Feedbacks and Convective Parameterization  

E-Print Network (OSTI)

) atmospheric energy transport per unit mass transport] of the model tropics converts the energy flux change 25% between the imposed oceanic flux and the resulting response in the atmospheric energy transportThe Tropical Response to Extratropical Thermal Forcing in an Idealized GCM: The Importance

Miami, University of

58

Quarterly Journal of the Royal Meteorological Society Q. J. R. Meteorol. Soc. (2013) Phenomenology of Sahelian convection observed in Niamey  

E-Print Network (OSTI)

Quarterly Journal of the Royal Meteorological Society Q. J. R. Meteorol. Soc. (2013) Phenomenology SM. 2013. Phenomenology of Sahelian convection observed in Niamey during the early monsoon. Q. J. R

Guichard, Francoise

59

Remote Sensing Observations from MTI Satellites and GMS Over Tropical Island of Nauru  

NLE Websites -- All DOE Office Websites (Extended Search)

Remote Sensing Observations from MTI Satellites and Remote Sensing Observations from MTI Satellites and GMS Over Tropical Island of Nauru W. M. Porch, P. Chylek, and B. Henderson Los Alamos National Laboratory Los Alamos, New Mexico Introduction The observations of island cloud trails have revealed a strong relationship between the character and frequency of occurrence of island cloud trails and the Tropical Ocean Southern Oscillation (MacFarlane et al. 2004 a, b). Island cloud trails from the U.S. Department of Energy's (DOE) Atmospheric and Radiation Measurement (ARM) facility of Nauru persist for more than 50 km (Nordeen et al. 2001) and resemble ship trail clouds found in the Eastern Ocean Margins (Porch et al. 1999). Island trail clouds are much more frequently observed during La Niña periods than El Niño periods (Figure 1). This

60

OBSERVATIONS OF CONVECTIVELY COUPLED KELVIN WAVES Convectively coupled Kelvin waves are large-scale, eastward-propagating tropical  

E-Print Network (OSTI)

in the extratropical forcing of these waves. Katherine H. Straub Department of Atmospheric Science Colorado State Randall, Richard Johnson, and Matthew Wheeler, whose comments and advice have significantly improved

Schubert, Wayne H.

Note: This page contains sample records for the topic "tropical convection observed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Retrieval of Hydrometeor Profiles in Tropical Cyclones and Convection from Combined Radar and Radiometer Observations  

E-Print Network (OSTI)

of understanding the global energy and water cycles by providing four-dimensional distributions of latent heat- ing related to latent heating, ice water content (IWC) and liquid water content (LWC) have implications A retrieval algorithm is described to estimate vertical profiles of precipitation ice water content and liquid

Jiang, Haiyan

62

Observations and Modeling of Shallow Convective Clouds: Implications for the Indirect Aerosol Effects  

NLE Websites -- All DOE Office Websites (Extended Search)

Observations Observations and Modeling of Shallow Convective Clouds: Implications for the Indirect Aerosol Effects Sylwester Arabas 1 , Joanna Slawinska 1 , Wojciech Grabowski 2 , Hugh Morrison 2 , Hanna Pawlowska 1 1 : Institute of Geophysics, University of Warsaw, Poland 2 : National Center for Atmospheric Research, Boulder, Colorado, USA 348 constants for reference state and lateral boundary conditions 349 ibcx=icyx 350 ibcy=icyy*j3 351 ibcz=icyz 352 irlx=irelx 353 irly=irely*j3 354 irdbc=0 355 fcr0=fcr0*icorio 356 itdl=0 357 tdt=40.*3600. 358 u0tdl=u00 359 360 361 constants for thermodynamics 362 c bv=sqrt(st*g) 363 bv=st 364 st=bv**2/g 365 cp=3.5*rg 366 cap=rg/cp 367 pr00=rg*rh00*tt00

63

An Observing System Simulation Experiment for the Unmanned Aircraft System Data Impact on Tropical Cyclone Track Forecasts  

Science Journals Connector (OSTI)

High-altitude, long-endurance unmanned aircraft systems (HALE UAS) are capable of extended flights for atmospheric sampling. A case study was conducted to evaluate the potential impact of dropwindsonde observations from HALE UAS on tropical ...

N. C. Privé; Yuanfu Xie; Steven Koch; Robert Atlas; Sharanya J. Majumdar; Ross N. Hoffman

2014-11-01T23:59:59.000Z

64

Observational Analysis of the Predictability of Mesoscale Convective Systems ISRAEL L. JIRAK AND WILLIAM R. COTTON  

E-Print Network (OSTI)

AND WILLIAM R. COTTON Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado merge into a large, long-lived organized convective system (Cotton and Anthes 1989). Thus, forecasting

65

Stratiform and Convective Precipitation Observed by Multiple Radars during the DYNAMO/AMIE Experiment  

Science Journals Connector (OSTI)

In this study, methods of convective/stratiform precipitation classification and surface rain-rate estimation based on the Atmospheric Radiation Measurement Program (ARM) cloud radar measurements were developed and evaluated. Simultaneous and ...

Min Deng; Pavlos Kollias; Zhe Feng; Chidong Zhang; Charles N. Long; Heike Kalesse; Arunchandra Chandra; Vickal V. Kumar; Alain Protat

2014-11-01T23:59:59.000Z

66

ARM - Publications: Science Team Meeting Documents: Tropical Warm Pool  

NLE Websites -- All DOE Office Websites (Extended Search)

Tropical Warm Pool International Cloud Experiment Tropical Warm Pool International Cloud Experiment May, Peter Bureau or Meteorology Research Centre Mather, James Pacific Northwest National Laboratory Jakob, Christian BMRC One of the most complete data sets describing tropical convection ever collected will result from the upcoming Tropical Warm Pool International Cloud Experiment (TWPICE) in the area around Darwin in late 2005 and early 2006. The aims of the experiment will be to examine convective cloud systems from their initial stages through to the decay of the cirrus generated and to measure their impact on the environment. The experiment design includes an unprecedented network of ground-based observations (soundings, active and passive remote sensors) combined with a large range of low, mid and high altitude aircraft for in-situ and remote sensing

67

Morphology, Intensity, and Rainfall Production of MJO Convection: Observations from DYNAMO Shipborne Radar and TRMM  

Science Journals Connector (OSTI)

This study uses DYNAMO shipborne (R/V Revelle) radar and TRMM Precipitation Radar (PR) datasets to investigate MJO-associated convective systems in specific organizational modes (MCS vs. sub-MCS, linear vs. non-linear). The Revelle radar sampled ...

Weixin Xu; Steven A. Rutledge

68

JOURNAL OF GEOPHYSICAL RESEARCH: ATMOSPHERES, VOL. 118, 96909707, doi:10.1002/jgrd.50781, 2013 Gravity waves generated by deep tropical convection: Estimates  

E-Print Network (OSTI)

in the Tropics are studied by analyzing in situ measurements from long-duration stratospheric balloons launched

Plougonven, Riwal

69

Quarterly Journal of the Royal Meteorological Society Q. J. R. Meteorol. Soc. 140: 500516, January 2014 B Phenomenology of Sahelian convection observed in Niamey  

E-Print Network (OSTI)

2014 B Phenomenology of Sahelian convection observed in Niamey during the early monsoon C. Dionea Citation: Dione C, Lothon M, Badiane D, Campistron B, Couvreux F, Guichard F, Sall SM. 2014. Phenomenology

Guichard, Francoise

70

On How Hot Towers Fuel the Hadley Cell: An Observational and Modeling Study of Line-Organized Convection in the Equatorial Trough from TOGA COARE  

Science Journals Connector (OSTI)

An airflow trajectory analysis was carried out based on an idealized numerical simulation of the nocturnal 9 February 1993 equatorial oceanic squall line observed over the Tropical Ocean and Global Atmosphere Coupled Ocean–Atmosphere Response ...

Alexandre O. Fierro; Joanne Simpson; Margaret A. LeMone; Jerry M. Straka; Bradley F. Smull

2009-09-01T23:59:59.000Z

71

Use of ARM observations and numerical models to determine radiative and latent heating profiles of mesoscale convective systems for general circulation models  

SciTech Connect

This three-year project, in cooperation with Professor Bob Houze at University of Washington, has been successfully finished as planned. Both ARM (the Atmospheric Radiation Measurement Program) data and cloud-resolving model (CRM) simulations were used to identify the water budgets of clouds observed in two international field campaigns. The research results achieved shed light on several key processes of clouds in climate change (or general circulation models), which are summarized below. 1. Revealed the effect of mineral dust on mesoscale convective systems (MCSs) Two international field campaigns near a desert and a tropical coast provided unique data to drive and evaluate CRM simulations, which are TWP-ICE (the Tropical Warm Pool International Cloud Experiment) and AMMA (the African Monsoon Multidisciplinary Analysis). Studies of the two campaign data were contrasted, revealing that much mineral dust can bring about large MCSs via ice nucleation and clouds. This result was reported as a PI presentation in the 3rd ASR Science Team meeting held in Arlington, Virginia in March 2012. A paper on the studies was published in the Journal of the Atmospheric Sciences (Zeng et al. 2013). 2. Identified the effect of convective downdrafts on ice crystal concentration Using the large-scale forcing data from TWP-ICE, ARM-SGP (the Southern Great Plains) and other field campaigns, Goddard CRM simulations were carried out in comparison with radar and satellite observations. The comparison between model and observations revealed that convective downdrafts could increase ice crystal concentration by up to three or four orders, which is a key to quantitatively represent the indirect effects of ice nuclei, a kind of aerosol, on clouds and radiation in the Tropics. This result was published in the Journal of the Atmospheric Sciences (Zeng et al. 2011) and summarized in the DOE/ASR Research Highlights Summaries (see http://www.arm.gov/science/highlights/RMjY5/view). 3. Used radar observations to evaluate model simulations In cooperation with Profs. Bob Houze at University of Washington and Steven Rutledge at Colorado State University, numerical model results were evaluated with observations from W- and C-band radars and CloudSat/TRMM satellites. These studies exhibited some shortcomings of current numerical models, such as too little of thin anvil clouds, directing the future improvement of cloud microphysics parameterization in CRMs. Two papers of Powell et al (2012) and Zeng et al. (2013), summarizing these studies, were published in the Journal of the Atmospheric Sciences. 4. Analyzed the water budgets of MCSs Using ARM data from TWP-ICE, ARM-SGP and other field campaigns, the Goddard CRM simulations were carried out to analyze the water budgets of clouds from TWP-ICE and AMMA. The simulations generated a set of datasets on clouds and radiation, which are available http://cloud.gsfc.nasa.gov/. The cloud datasets were available for modelers and other researchers aiming to improve the representation of cloud processes in multi-scale modeling frameworks, GCMs and climate models. Special datasets, such as 3D cloud distributions every six minutes for TWP-ICE, were requested and generated for ARM/ASR investigators. Data server records show that 86,206 datasets were downloaded by 120 users between April of 2010 and January of 2012. 5. MMF simulations The Goddard MMF (multi-scale modeling framework) has been improved by coupling with the Goddard Land Information System (LIS) and the Goddard Earth Observing System Model, Version 5 (GOES5). It has also been optimized on NASA HEC supercomputers and can be run over 4000 CPUs. The improved MMF with high horizontal resolution (1 x 1 degree) is currently being applied to cases covering 2005 and 2006. The results show that the spatial distribution pattern of precipitation rate is well simulated by the MMF through comparisons with satellite retrievals from the CMOPRH and GPCP data sets. In addition, the MMF results were compared with three reanalyses (MERRA, ERA-Interim and CFSR). Although the MMF tends

Tao, Wei-Kuo; Houze, Robert, A., Jr.; Zeng, Xiping

2013-03-14T23:59:59.000Z

72

Dynamical Simulations of North Atlantic Tropical Cyclone Activity Using Observed Low-Frequency SST Oscillation Imposed on CMIP5 Model RCP4.5 SST Projections  

Science Journals Connector (OSTI)

The effects on early and late twenty-first-century North Atlantic tropical cyclone statistics resulting from imposing the patterns of maximum/minimum phases of the observed Atlantic multidecadal oscillation (AMO) onto projected sea surface ...

Timothy E. LaRow; Lydia Stefanova; Chana Seitz

2014-11-01T23:59:59.000Z

73

Satellite and Argo observed surface salinity variations in the tropical Indian Ocean and their association with the Indian Ocean Dipole mode  

Science Journals Connector (OSTI)

This study investigates sea surface salinity (SSS) variations in the tropical Indian Ocean (IO) using the Aquarius/SAC-D and the Soil Moisture and Ocean Salinity (SMOS) satellite data and the Argo observations during July 2010-July 2014. Compared ...

DU Yan; ZHANG Yuhong

74

Optimizing the Probability of Flying in High Ice Water Content Conditions in the Tropics Using a Regional-Scale Climatology of Convective Cell Properties  

Science Journals Connector (OSTI)

In this paper, statistical properties of rainfall are derived from 14 years of Tropical Rainfall Measuring Mission data to optimize the use of flight hours for the upcoming High Altitude Ice Crystals (HAIC)/High Ice Water Content (HIWC) program. ...

A. Protat; S. Rauniyar; V. V. Kumar; J. W. Strapp

2014-11-01T23:59:59.000Z

75

16B.2 VERTICAL PROFILES OF TROPICAL CONVECTION AS OBSERVED BY THE TRMM SATELLITE Walter A. Petersen  

E-Print Network (OSTI)

characteristics. 2. DISTRIBUTIONS OF REFLECTIVITY AS COMPARED TO ICE WATER CONTENT AND LIGHTNING FLASH DENSITY ensembles. These differences are similarly manifested in plots of LIS Lightning Flash Density (LFD) and Ice; 2A-25 algorithm) and Lightning Imaging Sensor (LIS) data to conduct statistical studies

Rutledge, Steven

76

The Tropical Cyclone Diurnal Cycle of Mature Hurricanes  

Science Journals Connector (OSTI)

The diurnal cycle of tropical convection and the tropical cyclone (TC) cirrus canopy has been described extensively in previous studies. However, a complete understanding of the TC diurnal cycle remains elusive and is an area of ongoing research. ...

Jason P. Dunion; Christopher D. Thorncroft; Christopher S. Velden

2014-10-01T23:59:59.000Z

77

Convective Cells in Altocumulus Observed with a High-Resolution Radar  

Science Journals Connector (OSTI)

Very-high-resolution Doppler radar observations are used together with aircraft measurements to document the dynamic and thermodynamic structure of a dissipating altocumulus cloud system associated with a deep virga layer. The cloud layer ...

Jerome M. Schmidt; Piotr J. Flatau; Robert D. Yates

2014-06-01T23:59:59.000Z

78

A transilient matrix for moist convection  

SciTech Connect

A method is introduced for diagnosing a transilient matrix for moist convection. This transilient matrix quantifies the nonlocal transport of air by convective eddies: for every height z, it gives the distribution of starting heights z{prime} for the eddies that arrive at z. In a cloud-resolving simulation of deep convection, the transilient matrix shows that two-thirds of the subcloud air convecting into the free troposphere originates from within 100 m of the surface. This finding clarifies which initial height to use when calculating convective available potential energy from soundings of the tropical troposphere.

Romps, D.; Kuang, Z.

2011-08-15T23:59:59.000Z

79

The Dynamics and Predictability of Tropical Cyclones  

E-Print Network (OSTI)

to pinpoint sources of error in forecasts of tropical cyclone formation and intensification. Despite significant differences in methodology, storm environment and development, it is found in both situations that high convective instability (CAPE) and mid...

Sippel, Jason A.

2010-01-15T23:59:59.000Z

80

An Analytical Model for Tropical Relative Humidity  

Science Journals Connector (OSTI)

An analytical model is derived for tropical relative humidity using only the Clausius–Clapeyron relation, hydrostatic balance, and a bulk-plume water budget. This theory is constructed for radiative–convective equilibrium and compared against a ...

David M. Romps

2014-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical convection observed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Observations of the Evolution of the Nocturnal and Convective Boundary Layers and the Structure of Open-Celled Convection on 14 June 2002  

Science Journals Connector (OSTI)

The Boundary Layer Evolution (BLE) missions of the International H2O Project (IHOP_2002) were designed to provide comprehensive observations of the distribution of water vapor in the quiescent boundary layer and its evolution during the early ...

Lindsay J. Bennett; Tammy M. Weckwerth; Alan M. Blyth; Bart Geerts; Qun Miao; Yvette P. Richardson

2010-07-01T23:59:59.000Z

82

Observations of new aerosol particle formation in a tropical urban Raghu Betha a  

E-Print Network (OSTI)

fires were observed during the course of air sampling due to a prolonged dry spell in the months particles are also formed in the atmosphere through gas-to-particle conversion; this phenomenon is often on climate, especially on the number of cloud condensation nuclei (CCN) and the resulting ef- fects on cloud

Spracklen, Dominick

83

Tracking tropical cloud systems for the diagnosis of simulations by the weather research and forecasting (WRF) model  

SciTech Connect

To aid in improving model parameterizations of clouds and convection, we examine the capability of models, using explicit convection, to simulate the life cycle of tropical cloud systems in the tropical warm pool. The cloud life cycle is determined using a satellite cloud tracking algorithm (Boer and Ramanathan, J. Geophys. Res., 1997), and the statistics are compared to those of simulations using the Weather Research and Forecasting (WRF) Model. Using New York Blue, a Blue Gene/L supercomputer that is co-operated by Brookhaven and Stony Brook, simulations are run at a resolution comparable to the observations. Initial results suggest that the organization of the mesoscale convective systems is particularly sensitive to the cloud microphysics parameterization used.

Vogelmann, A.M.; Lin, W.; Cialella, A.; Luke, E. P.; Jensen, M. P.; Zhang, M. H.; Boer, E.

2010-06-27T23:59:59.000Z

84

Estimating Vertical Motion Profile Shape within Tropical Weather States over the Oceans  

Science Journals Connector (OSTI)

The vertical structure of tropical deep convection strongly influences interactions with larger-scale circulations and climate. This paper focuses on investigating this vertical structure and its relationship with mesoscale tropical weather ...

Zachary J. Handlos; Larissa E. Back

2014-10-01T23:59:59.000Z

85

Mesoscale Convective Vortices in Multiscale, Idealized Simulations: Dependence on Background State, Interdependency with Moist Baroclinic Cyclones, and Comparison with BAMEX Observations  

Science Journals Connector (OSTI)

A set of multiscale, nested, idealized numerical simulations of mesoscale convective systems (MCSs) and mesoscale convective vortices (MCVs) was conducted. The purpose of these simulations was to investigate the dependence of MCV development and ...

Robert J. Conzemius; Michael T. Montgomery

2010-04-01T23:59:59.000Z

86

Does the ECMWF IFS convection parameterisation with stochastic physics correctly reproduce relationships between convection and the large-scale state?  

Science Journals Connector (OSTI)

Important questions concerning parameterisation of tropical convection are how should sub-grid scale variability be represented, and which large-scale variables should be used in the parameterisations? Here we compare the statistics of ...

Peter A. G. Watson; H. M. Christensen; T. N. Palmer

87

Identifying the top of the tropical tropopause layer from vertical mass flux analysis and CALIPSO lidar cloud observations  

E-Print Network (OSTI)

defined as the level of zero net radiative heating, which occurs near 14.5­15 km [e.g., Folkins et al layer (TTL) by analyzing the vertical mass flux profile based on radiative transfer calculations will rise into the stratosphere. Thus convection has to transport air at least to the zero radiative heating

Hochberg, Michael

88

Development of Ensemble Neural Network Convection Parameterizations for Climate Models  

SciTech Connect

The novel neural network (NN) approach has been formulated and used for development of a NN ensemble stochastic convection parametrization for climate models. This fast parametrization is built based on data from Cloud Resolving Model (CRM) simulations initialized with and forced by TOGA-COARE data. The SAM (System for Atmospheric Modeling), developed by D. Randall, M. Khairoutdinov, and their collaborators, has been used for CRM simulations. The observational data are also used for validation of model simulations. The SAM-simulated data have been averaged and projected onto the GCM space of atmospheric states to implicitly define a stochastic convection parametrization. This parametrization is emulated using an ensemble of NNs. An ensemble of NNs with different NN parameters has been trained and tested. The inherent uncertainty of the stochastic convection parametrization derived in such a way is estimated. Due to these inherent uncertainties, NN ensemble is used to constitute a stochastic NN convection parametrization. The developed NN convection parametrization have been validated in a diagnostic CAM (CAM-NN) run vs. the control CAM run. Actually, CAM inputs have been used, at every time step of the control/original CAM integration, for parallel calculations of the NN convection parametrization (CAM-NN) to produce its outputs as a diagnostic byproduct. Total precipitation (P) and cloudiness (CLD) time series, diurnal cycles, and P and CLD distributions for the large Tropical Pacific Ocean for the parallel CAM-NN and CAM runs show similarity and consistency with the NCEP reanalysis. The P and CLD distributions for the tropical area for the parallel runs have been analyzed first for the TOGA-COARE boreal winter season (November 1992 through February 1993) and then for the winter seasons of the follow-up parallel decadal simulations. The obtained results are encouraging and practically meaningful. They show the validity of the NN approach. This constitutes an important practical conclusion of the study: the obtained results on NN ensembles as a stochastic physics parametrization show a realistic possibility of development of NN convection parametrization for climate (and NWP) models based on learning cloud physics from CRM/SAM simulated data.

Fox-Rabinovitz, M. S.; Krasnopolsky, V. M.

2012-05-02T23:59:59.000Z

89

Glacial Cooling in the Tropics: Exploring the Roles of Tropospheric Water Vapor, Surface Wind Speed, and Boundary Layer Processes  

Science Journals Connector (OSTI)

This paper is a modeling study of possible roles for tropospheric water vapor, surface wind speed, and boundary layer processes in glacial cooling in the Tropics. The authors divide the Tropics into a region of persistent deep convection and a ...

Richard Seager; Amy C. Clement; Mark A. Cane

2000-07-01T23:59:59.000Z

90

What causes the large extensions of red-supergiant atmospheres? Comparisons of interferometric observations with 1-D hydrostatic, 3-D convection, and 1-D pulsating model atmospheres  

E-Print Network (OSTI)

We present the atmospheric structure and the fundamental parameters of three red supergiants, increasing the sample of RSGs observed by near-infrared spectro-interferometry. Additionally, we test possible mechanisms that may explain the large observed atmospheric extensions of RSGs. We carried out spectro-interferometric observations of 3 RSGs in the near-infrared K-band with the VLTI/AMBER instrument at medium spectral resolution. To comprehend the extended atmospheres, we compared our observational results to predictions by available hydrostatic PHOENIX, available 3-D convection, and new 1-D self-excited pulsation models of RSGs. Our near-infrared flux spectra are well reproduced by the PHOENIX model atmospheres. The continuum visibility values are consistent with a limb-darkened disk as predicted by the PHOENIX models, allowing us to determine the angular diameter and the fundamental parameters of our sources. Nonetheless, in the case of V602 Car and HD 95686, the PHOENIX model visibilities do not predict ...

Arroyo-Torres, B; Chiavassa, A; Scholz, M; Freytag, B; Marcaide, J M; Hauschildt, P H; Wood, P R; Abellan, F J

2015-01-01T23:59:59.000Z

91

Convection towers  

DOE Patents (OSTI)

Convection towers which are capable of cleaning the pollution from large quantities of air, of generating electricity, and of producing fresh water utilize the evaporation of water sprayed into the towers to create strong airflows and to remove pollution from the air. Turbines in tunnels at the skirt section of the towers generate electricity, and condensers produce fresh water.

Prueitt, Melvin L. (Los Alamos, NM)

1996-01-01T23:59:59.000Z

92

Convection towers  

DOE Patents (OSTI)

Convection towers which are capable of cleaning the pollution from large quantities of air, of generating electricity, and of producing fresh water utilize the evaporation of water sprayed into the towers to create strong airflows and to remove pollution from the air. Turbines in tunnels at the skirt section of the towers generate electricity, and condensers produce fresh water.

Prueitt, Melvin L. (Los Alamos, NM)

1995-01-01T23:59:59.000Z

93

Convection towers  

DOE Patents (OSTI)

Convection towers which are capable of cleaning the pollution from large quantities of air, of generating electricity, and of producing fresh water utilize the evaporation of water sprayed into the towers to create strong airflows and to remove pollution from the air. Turbines in tunnels at the skirt section of the towers generate electricity, and condensers produce fresh water. 6 figs.

Prueitt, M.L.

1996-01-16T23:59:59.000Z

94

Convection towers  

DOE Patents (OSTI)

Convection towers which are capable of cleaning the pollution from large quantities of air and of generating electricity utilize the evaporation of water sprayed into the towers to create strong airflows and to remove pollution from the air. Turbines in tunnels at the skirt section of the towers generate electricity. Other embodiments may also provide fresh water, and operate in an updraft mode.

Prueitt, Melvin L. (Los Alamos, NM)

1994-01-01T23:59:59.000Z

95

Simple Multicloud Models for the Diurnal Cycle of Tropical Precipitation. Part I: Formulation and the Case of the Tropical Oceans  

Science Journals Connector (OSTI)

The variation of tropical precipitation due to the diurnal cycle of solar heating is examined here in the context of two simple models for tropical convection. The models utilize three cloud types—congestus, deep, and stratiform—that are believed ...

Yevgeniy Frenkel; Boualem Khouider; Andrew J. Majda

2011-10-01T23:59:59.000Z

96

Convection towers  

DOE Patents (OSTI)

Convection towers which are capable of cleaning the pollution from large quantities of air and of generating electricity utilize the evaporation of water sprayed into the towers to create strong airflows and to remove pollution from the air. Turbines in tunnels at the skirt section of the towers generate electricity. Other embodiments may also provide fresh water, and operate in an updraft mode. 5 figures.

Prueitt, M.L.

1994-02-08T23:59:59.000Z

97

Different convection models in ATLAS  

E-Print Network (OSTI)

Convection is an important phenomenon in the atmospheres of A-type and cooler stars. A description of convection in ATLAS models is presented, together with details of how it is specified in model calculations. The effects of changing the treatment of convection on model structures and how this affects observable quantities are discussed. The role of microturbulence is examined, and its link to velocity fields within the atmosphere. Far from being free parameters, mixing-length and microturbulence should be constrained in model calculations.

Barry Smalley

2005-09-19T23:59:59.000Z

98

Momentum and energy transport in the Sun's convection zone under the observational constraint of flux and temperature homogeneity at the surface  

Science Journals Connector (OSTI)

A previous authors' non-Boussinesq model of solar differential rotation (BPCM) is used to determine the angular velocity distribution within the convection zone, when the momentum ... boundary conditions expressi...

Gaetano Belvedere; Lucio Paternò

1978-11-01T23:59:59.000Z

99

Multiscale Variability of Deep Convection In Realation to Large-Scale Circulation in TOGA COARE  

Science Journals Connector (OSTI)

Deep convection over the Indo–Pacific oceanic warm pool in the Tropical Ocean Global Atmosphere Coupled Ocean–Atmosphere Response Experiment (TOGA COARE) occurred in cloud clusters, which grouped together in regions favoring their occurrence. ...

Shuyi S. Chen; Robert A. Houze Jr.; Brian E. Mapes

1996-05-01T23:59:59.000Z

100

Analysis of Strengthening and Dissipating Mesoscale Convective Systems Propagating off the West African Coast  

Science Journals Connector (OSTI)

A large number of Atlantic tropical depressions are generated in the eastern basin in relation to the African easterly wave (AEW) and embedded mesoscale convective systems (MCSs) coming from the African continent. In this paper, the structures of ...

Abdou L. Dieng; Laurence Eymard; Saidou M. Sall; Alban Lazar; Marion Leduc-Leballeur

2014-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical convection observed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Deep Convective Transition Characteristics in the Community Climate System Model and Changes under Global Warming  

Science Journals Connector (OSTI)

Tropical deep convective transition characteristics, including precipitation pickup, occurrence probability, and distribution tails related to extreme events, are analyzed using uncoupled and coupled versions of the Community Climate System Model (...

Sandeep Sahany; J. David Neelin; Katrina Hales; Richard B. Neale

2014-12-01T23:59:59.000Z

102

Evaluation of tropical cloud and precipitation statistics of CAM3 using CloudSat and CALIPSO data  

SciTech Connect

The combined CloudSat and CALIPSO satellite observations provide the first simultaneous measurements of cloud and precipitation vertical structure, and are used to examine the representation of tropical clouds and precipitation in the Community Atmosphere Model Version 3 (CAM3). A simulator package utilizing a model-to-satellite approach facilitates comparison of model simulations to observations, and a revised clustering method is used to sort the subgrid-scale patterns of clouds and precipitation into principal cloud regimes. Results from weather forecasts performed with CAM3 suggest that the model underestimates the horizontal extent of low and mid-level clouds in subsidence regions, but overestimates that of high clouds in ascending regions. CAM3 strongly overestimates the frequency of occurrence of the deep convection with heavy precipitation regime, but underestimates the horizontal extent of clouds and precipitation at low and middle levels when this regime occurs. This suggests that the model overestimates convective precipitation and underestimates stratiform precipitation consistent with a previous study that used only precipitation observations. Tropical cloud regimes are also evaluated in a different version of the model, CAM3.5, which uses a highly entraining plume in the parameterization of deep convection. While the frequency of occurrence of the deep convection with heavy precipitation regime from CAM3.5 forecasts decreases, the incidence of the low clouds with precipitation and congestus regimes increases. As a result, the parameterization change does not reduce the frequency of precipitating convection that is far too high relative to observations. For both versions of CAM, clouds and precipitation are overly reflective at the frequency of the CloudSat radar and thin clouds that could be detected by the lidar only are underestimated.

Zhang, Y; Klein, S; Boyle, J; Mace, G G

2008-11-20T23:59:59.000Z

103

Convective heater  

DOE Patents (OSTI)

A convective heater for heating fluids such as a coal slurry is constructed of a tube circuit arrangement which obtains an optimum temperature distribution to give a relatively constant slurry film temperature. The heater is constructed to divide the heating gas flow into two equal paths and the tube circuit for the slurry is arranged to provide a mixed flow configuration whereby the slurry passes through the two heating gas paths in successive co-current, counter-current and co-current flow relative to the heating gas flow. This arrangement permits the utilization of minimum surface area for a given maximum film temperature of the slurry consistent with the prevention of coke formation.

Thorogood, Robert M. (Macungie, PA)

1983-01-01T23:59:59.000Z

104

Convective heater  

DOE Patents (OSTI)

A convective heater for heating fluids such as a coal slurry is constructed of a tube circuit arrangement which obtains an optimum temperature distribution to give a relatively constant slurry film temperature. The heater is constructed to divide the heating gas flow into two equal paths and the tube circuit for the slurry is arranged to provide a mixed flow configuration whereby the slurry passes through the two heating gas paths in successive co-current, counter-current and co-current flow relative to the heating gas flow. This arrangement permits the utilization of minimum surface area for a given maximum film temperature of the slurry consistent with the prevention of coke formation.

Thorogood, Robert M. (Macungie, PA)

1986-01-01T23:59:59.000Z

105

Data assimilation for stratified convection  

E-Print Network (OSTI)

We show how the 3DVAR data assimilation methodology can be used in the astrophysical context of a two-dimensional convection flow. We study the way this variational approach finds best estimates of the current state of the flow from a weighted average of model states and observations. We use numerical simulations to generate synthetic observations of a vertical two-dimensional slice of the outer part of the solar convection zone for varying noise levels and implement 3DVAR when the covariance matrices are scalar. Our simulation results demonstrate the capability of 3DVAR to produce error estimates of system states between up to tree orders of magnitude below the original noise level present in the observations. This work exemplifies the importance of applying data assimilation techniques in simulations of the stratified convection.

Svedin, Andreas; Brandenburg, Axel

2013-01-01T23:59:59.000Z

106

ARM - Evaluation Product - Convective Vertical Velocity  

NLE Websites -- All DOE Office Websites (Extended Search)

ProductsConvective Vertical Velocity ProductsConvective Vertical Velocity Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Evaluation Product : Convective Vertical Velocity 2011.04.25 - 2011.05.23 Site(s) SGP General Description Convective processes play an important role in Earth's energy balance by distributing heat and moisture throughout the atmosphere. In particular, vertical air motions associated with these processes are inherently linked to the life cycle of these convective systems and are therefore directly tied to their energy budget. However, direct measurements of vertical air motions (e.g., in situ aircraft observations) are sparse, making it difficult to compare them with numerical model output, which relies on convective parameterization schemes that have yet to be extensively

107

HEAT TRANSFERS IN A DOUBLE SKIN ROOF VENTILATED BY NATURAL CONVECTION IN SUMMER TIME  

E-Print Network (OSTI)

1 HEAT TRANSFERS IN A DOUBLE SKIN ROOF VENTILATED BY NATURAL CONVECTION IN SUMMER TIME P. H or in tropical and arid countries. In this work, radiation, convection and conduction heat transfers-dimensional numerical simulation of the heat transfers through the double skin reveals the most important parameters

Boyer, Edmond

108

Warm Core Structures in Organized Cloud Clusters Developing or Not Developing into Tropical Storms Observed by the Advanced Microwave Sounding Unit  

Science Journals Connector (OSTI)

The temperature profiles of organized cloud clusters developing or not developing (nondeveloping) into tropical storms (TSs; maximum surface wind >34 kt) over the western North Pacific in 2004 were investigated using Advanced Microwave Sounding ...

Kotaro Bessho; Tetsuo Nakazawa; Shuji Nishimura; Koji Kato

2010-07-01T23:59:59.000Z

109

Latent heating contribution from precipitation systems with different sizes, depths and intensities in the tropics  

Science Journals Connector (OSTI)

Latent Heating (LH) from precipitation systems with different sizes, depths and convective intensities are quantified with 15 years of LH retrievals from Version 7 Precipitation Radar (PR) products of the Tropical Rainfall Measuring Mission (TRMM)...

Chuntao Liu; Shoichi Shige; Yukari N. Takayabu; Edward Zipser

110

Transport Processes in the Tropical Warm Pool Boundary Layer. Part II: Vertical Structure and Variability  

Science Journals Connector (OSTI)

The structure of the intertropical convergence zone ITCZ cloud-topped marine atmospheric boundary layer away from the most intense mesoscale convective systems during the Tropical Ocean Global Atmosphere Coupled Ocean–Atmosphere Response ...

A. G. Williams; J. M. Hacker; H. Kraus

1997-08-01T23:59:59.000Z

111

On the Diurnal Cycle of Deep Convection, High-Level Cloud, and Upper Troposphere Water Vapor in the Multiscale Modeling Framework  

SciTech Connect

The Multiscale Modeling Framework (MMF), also called ‘‘superparameterization’’, embeds a cloud-resolving model (CRM) at each grid column of a general circulation model to replace traditional parameterizations of moist convection and large-scale condensation. This study evaluates the diurnal cycle of deep convection, high-level clouds, and upper troposphere water vapor by applying an infrared (IR) brightness temperature (Tb) and a precipitation radar (PR) simulator to the CRM column data. Simulator results are then compared with IR radiances from geostationary satellites and PR reflectivities from the Tropical Rainfall Measuring Mission (TRMM). While the actual surface precipitation rate in the MMF has a reasonable diurnal phase and amplitude when compared with TRMM observations, the IR simulator results indicate an inconsistency in the diurnal anomalies of high-level clouds between the model and the geostationary satellite data. Primarily because of its excessive high-level clouds, the MMF overestimates the simulated precipitation index (PI) and fails to reproduce the observed diurnal cycle phase relationships among PI, high-level clouds, and upper troposphere relative humidity. The PR simulator results show that over the tropical oceans, the occurrence fraction of reflectivity in excess of 20 dBZ is almost 1 order of magnitude larger than the TRMM data especially at altitudes above 6 km. Both results suggest that the MMF oceanic convection is overactive and possible reasons for this bias are discussed. However, the joint distribution of simulated IR Tb and PR reflectivity indicates that the most intense deep convection is found more often over tropical land than ocean, in agreement with previous observational studies.

Zhang, Yunyan; Klein, Stephen A.; Liu, Chuntao; Tian, Baijun; Marchand, Roger T.; Haynes, J. M.; McCoy, Renata; Zhang, Yuying; Ackerman, Thomas P.

2008-08-22T23:59:59.000Z

112

Radiative Heating of the ISCCP Upper Level Cloud Regimes and its Impact on the Large-scale Tropical Circulation  

SciTech Connect

Radiative heating profiles of the International Satellite Cloud Climatology Project (ISCCP) cloud regimes (or weather states) were estimated by matching ISCCP observations with radiative properties derived from cloud radar and lidar measurements from the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) sites at Manus, Papua New Guinea, and Darwin, Australia. Focus was placed on the ISCCP cloud regimes containing the majority of upper level clouds in the tropics, i.e., mesoscale convective systems (MCSs), deep cumulonimbus with cirrus, mixed shallow and deep convection, and thin cirrus. At upper levels, these regimes have average maximum cloud occurrences ranging from 30% to 55% near 12 km with variations depending on the location and cloud regime. The resulting radiative heating profiles have maxima of approximately 1 K/day near 12 km, with equal heating contributions from the longwave and shortwave components. Upper level minima occur near 15 km, with the MCS regime showing the strongest cooling of 0.2 K/day and the thin cirrus showing no cooling. The gradient of upper level heating ranges from 0.2 to 0.4 K/(day?km), with the most convectively active regimes (i.e., MCSs and deep cumulonimbus with cirrus) having the largest gradient. When the above heating profiles were applied to the 25-year ISCCP data set, the tropics-wide average profile has a radiative heating maximum of 0.45Kday-1 near 250 hPa. Column-integrated radiative heating of upper level cloud accounts for about 20% of the latent heating estimated by the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR). The ISCCP radiative heating of tropical upper level cloud only slightly modifies the response of an idealized primitive equation model forced with the tropics-wide TRMM PR latent heating, which suggests that the impact of upper level cloud is more important to large-scale tropical circulation variations because of convective feedbacks rather than direct forcing by the cloud radiative heating profiles. However, the height of the radiative heating maxima and gradient of the heating profiles are important to determine the sign and patterns of the horizontal circulation anomaly driven by radiative heating at upper levels.

Li, Wei; Schumacher, Courtney; McFarlane, Sally A.

2013-01-31T23:59:59.000Z

113

Momentum transport processes in the stratiform regions of mesoscale convective systems over the western Pacific warm pool  

E-Print Network (OSTI)

Momentum transport by the stratiform components of mesoscale convective systems (MCSs) during the Tropical Ocean–Global Atmosphere Coupled Ocean–Atmosphere Response Experiment in December 1992 is investigated using a ...

Mechem, David B.; Chen, Shuyi S.; Houze, Robert A. Jr.

2006-04-01T23:59:59.000Z

114

The influence of tropical heating displacements on the extratropical climate  

SciTech Connect

The hypothesis is advanced that a latitudinal shift in the tropical convective heating pattern can significantly alter temperatures in the extratropics. Results of a simplified GCM show that the shift of a prescribed tropical heating toward the summer pole, on time scales longer than a few weeks, leads to a more intense cross-equatorial [open quotes]winter[close quotes] Hadley circulation, enhanced upper-level tropical easterlies, and a slightly stronger subtropical winter jet, accompanied by warming at the winter middle and high latitudes as a result of increased dynamical heating. The indications are that there is a robust connection between the net dynamic heating in the extratropics and the implied changes in the subtropical wind shear resulting from adjustments in the Hadley circulation associated with convective heating displacements in the tropics. The implications are that (i) the low-frequency temporal variability in the Hadley circulation may play an important role in modulating wave transport in the winter extratropics, (ii) the global climate may be sensitive to those processes that control deep cumulus convection in the tropics, and (iii) systematic temperature biases in GCMs may be reduced by improving the tropical rainfall simulation. 43 refs., 49 figs.

Hou, A.Y. (NASA/Goddard Space Flight Center, Greenbelt, MD (United States))

1993-11-01T23:59:59.000Z

115

SURFACE TENSION DRIVEN CONVECTION  

E-Print Network (OSTI)

SURFACE TENSION DRIVEN CONVECTION DIJKSTRA, SENGUL, WANG INTRODUCTION LINEAR THEORY MAIN THEOREMS CONCLUDING REMARKS DYNAMIC TRANSITIONS OF SURFACE TENSION DRIVEN CONVECTION H.Dijkstra T. Sengul S. Wang #12;SURFACE TENSION DRIVEN CONVECTION DIJKSTRA, SENGUL, WANG INTRODUCTION LINEAR THEORY MAIN THEOREMS

Wang, Shouhong

116

Modeling convection in the Greenland Sea  

E-Print Network (OSTI)

A detailed examination of the development of a deep convection event observed in the Greenland Sea in 1988-89 is carried out through a combination of modeling, scale estimates, and data analysis. We develop a prognostic ...

Bhushan, Vikas

1998-01-01T23:59:59.000Z

117

Assimilation of high-resolution tropical cyclone observations with an Ensemble Kalman Filter Using HEDAS: Evaluation of 2008-2011 HWRF forecasts  

Science Journals Connector (OSTI)

NOAA has been gathering high-resolution flight-level, dropwindsonde and airborne Doppler radar data in tropical cyclones for almost three decades; the U.S. Air Force routinely obtained the same type and quality of data, excepting Doppler radar, ...

Sim D. Aberson; Altu? Aksoy; Kathryn J. Sellwood; Tomislava Vukicevic; Xuejin Zhang

118

Building Blocks of Tropical Diabatic Heating  

SciTech Connect

Rotated EOF analyses are used to study the composition and variability of large-scale tropical diabatic heating profiles estimated from eight field campaigns. The results show that the profiles are composed of a pair of building blocks. These are the stratiform heating with peak heating near 400hpa and a cooling peak near 700hPa and convective heating with a heating maximum near 700hPa. Variations in the contributions of these building blocks account for the evolution of the large-scale heating profile. Instantaneous top (bottom) heavy large scale heating profiles associated with excess of stratiform (convective) heating evolve towards a stationary mean profile due to exponential decay of the excess stratiform (convective) heating.

Hagos, Samson M.

2010-07-01T23:59:59.000Z

119

Convective cell development and propagation in a mesoscale convective complex  

E-Print Network (OSTI)

~ , National Fisheries University of Pusan Chairman of Advisory Committee: Dr ~ Kennth CD Brundidge A case study was made of the mesoscale convective complex (MCC) which occurred over southern Oklahoma and northern Texas on 27 May 1981. This storm moved... in an east-southeasterly direction and during much of its lifetime was observable by radars at Oklahoma City, OK and Stephenville, TX. It was found that the direction of cell (VIP level 3 or more reflectivity) propagation was somewhat erratic...

Ahn, Yoo-Shin

2012-06-07T23:59:59.000Z

120

The convective structures associated with cloud-to-ground lightning in TOGA COARE Mesoscale Convective Systems  

E-Print Network (OSTI)

indicate a pronounced difference between lightning producing and non-lightning producing cells. Lightning producing convective cells have higher radar reflectivity in the 5.0- 8.0 km layer, and a slower decrease with height, both observations indicating...

Restivo, Michael Edward

2012-06-07T23:59:59.000Z

Note: This page contains sample records for the topic "tropical convection observed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

ARM Convective Available Potential Energy (CAPE), Convective Inhibition (CIN) Product  

SciTech Connect

ARM soundings are used to determine Convective Available Potential Energy (CAPE), Convective Inhibition (CIN) and associated properties, using the following relationships;

Jensen, Michael

2014-04-10T23:59:59.000Z

122

ARM Convective Available Potential Energy (CAPE), Convective Inhibition (CIN) Product  

DOE Data Explorer (OSTI)

ARM soundings are used to determine Convective Available Potential Energy (CAPE), Convective Inhibition (CIN) and associated properties, using the following relationships;

Jensen, Michael

123

Heat Transfer and Convection Currents  

Science Journals Connector (OSTI)

...October 1965 research-article Heat Transfer and Convection Currents D. C...convection in a medium with internal heat generation is discussed semi-quantitatively...States English United Kingdom 1966 Heat transfer and convection currents Tozer D...

1965-01-01T23:59:59.000Z

124

The Impact of Data Assimilation Length Scales on Analysis and Prediction of Convective Storms  

Science Journals Connector (OSTI)

An idealized convective test bed for the local ensemble transform Kalman filter (LETKF) is set up to perform storm-scale data assimilation of simulated Doppler radar observations. Convective systems with lifetimes exceeding 6 h are triggered in a ...

Heiner Lange; George C. Craig

2014-10-01T23:59:59.000Z

125

Mechanisms initiating deep convection over complex terrain during COPS.  

SciTech Connect

Precipitating convection in a mountain region of moderate topography is investigated, with particular emphasis on its initiation in response to boundary-layer and mid- and upper-tropospheric forcing mechanisms. The data used in the study are from COPS (Convective and Orographically-induced Precipitation Study) that took place in southwestern Germany and eastern France in the summer of 2007. It is found that the initiation of precipitating convection can be roughly classified as being due to either: (i) surface heating and low-level flow convergence; (ii) surface heating and moisture supply overcoming convective inhibition during latent and/or potential instability; or (iii) mid-tropospheric dynamical processes due to mesoscale convergence lines and forced mean vertical motion. These phenomena have to be adequately represented in models in order to improve quantitative precipitation forecast. Selected COPS cases are analyzed and classified into these initiation categories. Although only a subset of COPS data (mainly radiosondes, surface weather stations, radar and satellite data) are used here, it is shown that convective systems are captured in considerable detail by sensor synergy. Convergence lines were observed by Doppler radar in the location where deep convection is triggered several hours later. The results suggest that in many situations, observations of the location and timing of convergence lines will facilitate the nowcasting of convection. Further on, forecasting of the initiation of convection is significantly complicated if advection of potentially convective air masses over changing terrain features plays a major role. The passage of a frontal structure over the Vosges - Rhine valley - Black Forest orography was accompanied by an intermediate suppression of convection over the wide Rhine valley. Further downstream, an intensification of convection was observed over the Black Forest due to differential surface heating, a convergence line, and the flow generated by a gust front.

Kottmeier, C.; Kalthoff, N.; Barthlott, C.; Corsmeier, U.; Van Baelen, J.; Coulter, R.; Environmental Science Division; Inst. for Meteorology and Climate Research; Lab. de Meteorologie Physique; Inst. of Physics and Meteorology

2008-12-01T23:59:59.000Z

126

Layer inflow into precipitating convection over the western tropical Pacific  

E-Print Network (OSTI)

and the relativecoarseness of the TOGA COARE soundings.The available input data from the mesoscale model consist of three wind components(u, v and w), temperature, pressure, water vapour, rain water, cloud water and cloudice. The last two quantities, by de? nition, have zero... by linear interpolation of the hourly supplied MM5 data, to the right-hand side of the u, v, w, temperature, pressure and water vapour equations in a narrowzone near the lateral boundaries. The forcing is strongest at the boundary and decreasesto a ? fth...

Mechem, David B.; Houze, Robert A. Jr.; Chen, Shuyi S.

2002-07-01T23:59:59.000Z

127

Vertical velocity in oceanic convection off tropical Australia  

E-Print Network (OSTI)

. . . . . . . v Vl Vl I I 1 3 6 10 Description of the Data Data Processing . . Event Criteria 10 15 21 III RESULTS . . . 26 Cores. Environment 26 34 IV COMPARISON WITH OTHER STUDIES . . . . . 40 Cores... Variations with altitude of median and strongest 10'/o-level statistics of (a) average vertical velocity, (b) maximum vertical velocity, (c) mass flux per unit length normal to the flight track and (d) diameter 32 Figure Page Reconstructed temperature...

Lucas, Christopher

2012-06-07T23:59:59.000Z

128

Use of ARM observations and numerical models to determine radiative and latent heating profiles of mesoscale convective systems for general circulation models  

SciTech Connect

We examined cloud radar data in monsoon climates, using cloud radars at Darwin in the Australian monsoon, on a ship in the Bay of Bengal in the South Asian monsoon, and at Niamey in the West African monsoon. We followed on with a more in-depth study of the continental MCSs over West Africa. We investigated whether the West African anvil clouds connected with squall line MCSs passing over the Niamey ARM site could be simulated in a numerical model by comparing the observed anvil clouds to anvil structures generated by the Weather Research and Forecasting (WRF) mesoscale model at high resolution using six different ice-phase microphysical schemes. We carried out further simulations with a cloud-resolving model forced by sounding network budgets over the Niamey region and over the northern Australian region. We have devoted some of the effort of this project to examining how well satellite data can determine the global breadth of the anvil cloud measurements obtained at the ARM ground sites. We next considered whether satellite data could be objectively analyzed to so that their large global measurement sets can be systematically related to the ARM measurements. Further differences were detailed between the land and ocean MCS anvil clouds by examining the interior structure of the anvils with the satellite-detected the CloudSat Cloud Profiling Radar (CPR). The satellite survey of anvil clouds in the Indo-Pacific region was continued to determine the role of MCSs in producing the cloud pattern associated with the MJO.

Houze, Jr., Robert A. [University of Washington Dept. of Atmospheric Sciences

2013-11-13T23:59:59.000Z

129

Convective Cloud Lifecycles Lunchtime seminar  

E-Print Network (OSTI)

Convective Cloud Lifecycles Lunchtime seminar 19th May 2009 Bob Plant Department of Meteorology, University of Reading, UK #12;Introduction Obtain life cycle statistics for clouds in CRM simulations Why Conclusions Convective Cloud Lifecycles ­ p.1/3 #12;Why bother? Convective Cloud Lifecycles ­ p.2/3 #12;Some

Plant, Robert

130

Vertical Structure of Convective Systems during NAME 2004  

Science Journals Connector (OSTI)

This study describes the vertical structure of mesoscale convective systems (MCSs) that characterized the 2004 North American monsoon utilizing observations from a 2875-MHz (S band) profiler and a dual-polarimetric scanning Doppler radar. Both ...

David G. Lerach; Steven A. Rutledge; Christopher R. Williams; Robert Cifelli

2010-05-01T23:59:59.000Z

131

A Unified Convection Scheme (UNICON). Part II: Simulation  

Science Journals Connector (OSTI)

A unified convection scheme (UNICON) is implemented into the Community Atmosphere Model, version 5 (CAM5), and tested in single-column and global simulations forced by observed sea surface temperature. Compared to CAM5, UNICON substantially ...

Sungsu Park

2014-11-01T23:59:59.000Z

132

Can the vertical motions in the eyewall of tropical cyclones support persistent UAV flight?  

E-Print Network (OSTI)

Powered flights in the form of manned or unmanned aerial vehicles (UAVs) have been flying into tropical cyclones to obtain vital atmospheric measurements with flight duration typically lasting between 12 and 36 hours. Convective vertical motion properties of tropical cyclones have previously been studied. This work investigates the possibility to achieve persistent flight by harnessing the generally pervasive updrafts in the eyewall of tropical cyclones. A sailplane UAV capable of vertical take-off and landing (VTOL) is proposed and its flight characteristics simulated. Results suggest that the concept of persistent flight within the eyewall is promising and may be extendable to the rainband regions.

Poh, Chung-Kiak

2014-01-01T23:59:59.000Z

133

Tropical and subtropical cloud transitions in weather and climate prediction models: the GCSS/WGNE Pacific Cross-Section Intercomparison (GPCI)  

SciTech Connect

A model evaluation approach is proposed where weather and climate prediction models are analyzed along a Pacific Ocean cross-section, from the stratocumulus regions off the coast of California, across the shallow convection dominated trade-winds, to the deep convection regions of the ITCZ: the GCSS/WGNE Pacific Cross-section Intercomparison (GPCI). The main goal of GPCI is to evaluate, and help understand and improve the representation of tropical and sub-tropical cloud processes in weather and climate prediction models. In this paper, a detailed analysis of cloud regime transitions along the cross-section from the sub-tropics to the tropics for the season JJA of 1998 is presented. This GPCI study confirms many of the typical weather and climate prediction model problems in the representation of clouds: underestimation of clouds in the stratocumulus regime by most models with the corresponding consequences in terms of shortwave radiation biases; overestimation of clouds by the ECMWF Re-Analysis (ERA40) in the deep tropics (in particular) with the corresponding impact in the outgoing longwave radiation; large spread between the different models in terms of cloud cover, liquid water path and shortwave radiation; significant differences between the models in terms of vertical crosssections of cloud properties (in particular), vertical velocity and relative humidity. An alternative analysis of cloud cover mean statistics is proposed where sharp gradients in cloud cover along the GPCI transect are taken into account. This analysis shows that the negative cloud bias of some models and ERA40 in the stratocumulus regions (as compared to ISCCP) is associated not only with lower values of cloud cover in these regimes, but also with a stratocumulus-to-cumulus transition that occurs too early along the trade-wind Lagrangian trajectory. Histograms of cloud cover along the cross-section differ significantly between models. Some models exhibit a quasi-bimodal structure with cloud cover being either very large (close to 100%) or very small, while other models show a more continuous transition. The ISCCP observations suggest that reality is in-between these two extreme examples. These different patterns reflect the diverse nature of the cloud, boundary layer, and convection parameterizations in the participating weather and climate prediction models.

Teixeira, J.; Cardoso, S.; Bonazzola, M.; Cole, Jason N.; DelGenio, Anthony D.; DeMott, C.; Franklin, A.; Hannay, Cecile; Jakob, Christian; Jiao, Y.; Karlsson, J.; Kitagawa, H.; Koehler, M.; Kuwano-Yoshida, A.; LeDrian, C.; Lock, Adrian; Miller, M.; Marquet, P.; Martins, J.; Mechoso, C. R.; Meijgaard, E. V.; Meinke, I.; Miranda, P.; Mironov, D.; Neggers, Roel; Pan, H. L.; Randall, David A.; Rasch, Philip J.; Rockel, B.; Rossow, William B.; Ritter, B.; Siebesma, A. P.; Soares, P.; Turk, F. J.; Vaillancourt, P.; Von Engeln, A.; Zhao, M.

2011-11-01T23:59:59.000Z

134

Ocean Barrier Layers’ Effect on Tropical Cyclone Intensification  

SciTech Connect

Improving a tropical cyclone's forecast and mitigating its destructive potential requires knowledge of various environmental factors that influence the cyclone's path and intensity. Herein, using a combination of observations and model simulations, we systematically demonstrate that tropical cyclone intensification is significantly affected by salinity-induced barrier layers, which are 'quasi-permanent' features in the upper tropical oceans. When tropical cyclones pass over regions with barrier layers, the increased stratification and stability within the layer reduce storm-induced vertical mixing and sea surface temperature cooling. This causes an increase in enthalpy flux from the ocean to the atmosphere and, consequently, an intensification of tropical cyclones. On average, the tropical cyclone intensification rate is nearly 50% higher over regions with barrier layers, compared to regions without. Our finding, which underscores the importance of observing not only the upper-ocean thermal structure but also the salinity structure in deep tropical barrier layer regions, may be a key to more skillful predictions of tropical cyclone intensities through improved ocean state estimates and simulations of barrier layer processes. As the hydrological cycle responds to global warming, any associated changes in the barrier layer distribution must be considered in projecting future tropical cyclone activity.

Balaguru, Karthik; Chang, P.; Saravanan, R.; Leung, Lai-Yung R.; Xu, Zhao; Li, M.; Hsieh, J.

2012-09-04T23:59:59.000Z

135

Cyclone Center Using Crowdsourcing to Determine Tropical Cyclone Intensity  

E-Print Network (OSTI)

Cyclone Center Using Crowdsourcing to Determine Tropical Cyclone Intensity Almost all tropical cyclones are not directly observed. Agency estimates of storm position and intensity are not homogeneous in time and space. Cyclone Center uses crowdsourcing to collect data that will lead to a consistent

Hennon, Christopher C.

136

Sensitivity of global tropical climate to land surface processes: Mean state and interannual variability  

SciTech Connect

This study examines the sensitivity of global tropical climate to land surface processes (LSP) using an atmospheric general circulation model both uncoupled (with prescribed SSTs) and coupled to an oceanic general circulation model. The emphasis is on the interactive soil moisture and vegetation biophysical processes, which have first order influence on the surface energy and water budgets. The sensitivity to those processes is represented by the differences between model simulations, in which two land surface schemes are considered: 1) a simple land scheme that specifies surface albedo and soil moisture availability, and 2) the Simplified Simple Biosphere Model (SSiB), which allows for consideration of interactive soil moisture and vegetation biophysical process. Observational datasets are also employed to assess the reality of model-revealed sensitivity. The mean state sensitivity to different LSP is stronger in the coupled mode, especially in the tropical Pacific. Furthermore, seasonal cycle of SSTs in the equatorial Pacific, as well as ENSO frequency, amplitude, and locking to the seasonal cycle of SSTs are significantly modified and more realistic with SSiB. This outstanding sensitivity of the atmosphere-ocean system develops through changes in the intensity of equatorial Pacific trades modified by convection over land. Our results further demonstrate that the direct impact of land-atmosphere interactions on the tropical climate is modified by feedbacks associated with perturbed oceanic conditions ("indirect effect" of LSP). The magnitude of such indirect effect is strong enough to suggest that comprehensive studies on the importance of LSP on the global climate have to be made in a system that allows for atmosphere-ocean interactions.

Ma, Hsi-Yen; Xiao, Heng; Mechoso, C. R.; Xue, Yongkang

2013-03-01T23:59:59.000Z

137

CAPE in Tropical Cyclones  

E-Print Network (OSTI)

1999) found that lightning flash frequency was proportionallightning distribution in tropical cyclones. The ratio of downshear to upshear flasheslightning from 100-300 km radii found by Corbosiero and Molinari (2003), with larger CAPE associated with greater flash

Molinari, J.

2014-01-01T23:59:59.000Z

138

The multiple vortex nature of tropical cyclogenesis  

E-Print Network (OSTI)

) __________________________ __________________________ John Nielsen-Gammon Craig Epifanio (Chair of Committee) (Member) __________________________ __________________________ Fuqing Zhang Hongxing Liu (Member) (Member) December 2004 Major Subject: Atmospheric Sciences... iii ABSTRACT The Multiple Vortex Nature of Tropical Cyclogenesis. (December 2004) Jason Allen Sippel, B.S., Texas A&M University Chair of Advisory Committee: Dr. John Nielsen-Gammon This thesis contains an observational analysis...

Sippel, Jason Allen

2005-02-17T23:59:59.000Z

139

Eddy formation and propagation in the eastern tropical Pacific  

E-Print Network (OSTI)

Observations of eddies in the eastern tropical Pacific from TOPEX altimetry data show that there are seasonal and interannual variations in eddy activity. Comparisons between time of eddy formation and corresponding wind data show that not all...

Jhingran, Vikas Gopal

2012-06-07T23:59:59.000Z

140

Reduction of tropical land region precipitation variability via transpiration  

E-Print Network (OSTI)

Tropical rainforests are known to exhibit low intraseasonal precipitation variability compared with oceanic areas with similar mean precipitation in observations and models. In the present study, the potential role of ...

Lee, Jung-Eun

Note: This page contains sample records for the topic "tropical convection observed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Biodiversity Conservation in Tropical Agroecosystems  

E-Print Network (OSTI)

Biodiversity Conservation in Tropical Agroecosystems A New Conservation Paradigm Ivette Perfectoa areas of the world. Although most ecologists con- cerned with biodiversity conservation would agree. This conclusion has major consequences for biodiversity con- servation in fragmented tropical forests

142

A three-dimensional numerical model of dry convection in an ambient wind field  

E-Print Network (OSTI)

effects of the ambient wind field on convection. Nost of the numerical results are shown to correspond to empirical observations, while some results are unexpected but reasonable. Nechanical and thermal energy equations have been developed... to investigate the effects on convection of an The citations on the following pages follow the tyl of th J* J of ~At * h ' f ambient wind with a vertical shear He also examined the energy interactions between convective flow and nean flows. There were many...

Burgeson, John Carl

2012-06-07T23:59:59.000Z

143

Measurements of Heavy Convective Rainfall in the Presence of Hail in Flood-Prone Areas Using an X-Band Polarimetric Radar  

Science Journals Connector (OSTI)

The utility of X-band polarimetric radar to provide rainfall estimations with high spatial and temporal resolution in heavy convective precipitation in the presence of hail is explored. A case study involving observations of strong convective ...

Sergey Y. Matrosov; Robert Cifelli; David Gochis

2013-02-01T23:59:59.000Z

144

ARM - Field Campaign - Observations and Modeling of the Green Ocean Amazon  

NLE Websites -- All DOE Office Websites (Extended Search)

govCampaignsObservations and Modeling of the Green Ocean Amazon Aerial govCampaignsObservations and Modeling of the Green Ocean Amazon Aerial Campaign Campaign Links GOAMAZON Website Related Campaigns Observations and Modeling of the Green Ocean Amazon (GOAMAZON 2014) 2014.01.01, Martin, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Observations and Modeling of the Green Ocean Amazon Aerial Campaign 2014.02.15 - 2014.10.15 Lead Scientist : Scot Martin Description The hydrologic cycle of the Amazon Basin is one of the primary heat engines of the Southern Hemisphere. Any accurate climate model must succeed in a good description of the Basin, both in its natural state and in states perturbed by regional and global human activities. At the present time, however, tropical deep convection in a natural state is poorly understood

145

Tropical Limit in Statistical Physics  

E-Print Network (OSTI)

Tropical limit for macroscopic systems in equilibrium defined as the formal limit of Boltzmann constant k going to 0 is discussed. It is shown that such tropical limit is well-adapted to analyse properties of systems with highly degenerated energy levels, particularly of frustrated systems like spin ice and spin glasses. Tropical free energy is a piecewise linear function of temperature, tropical entropy is a piecewise constant function and the system has energy for which tropical Gibbs' probability has maximum. Properties of systems in the points of jump of entropy are studied. Systems with finite and infinitely many energy levels and phenomena of limiting temperatures are discussed.

M. Angelelli; B. Konopelchenko

2015-02-04T23:59:59.000Z

146

Water and tropical agriculture  

Science Journals Connector (OSTI)

... covers what is potentially an important field. The author has spent six years lecturing in Tanzania, so he has first-hand experience of the problems and is well qualified to ... depends largely on the available radiation, but there is no discussion of the distribution of solar radiation in the tropical world. Given an adequate water supply, plant yields depend to ...

J. G. Lockwood

1977-09-08T23:59:59.000Z

147

Tropical Cyclone Eye Thermodynamics  

Science Journals Connector (OSTI)

In intense tropical cyclones, sea level pressures at the center are 50–100 hPa lower than outside the vortex, but only 10–30 hPa of the total pressure fall occurs inside the eye between the eyewall and the center. Warming by dry subsidence ...

H. E. Willoughby

1998-12-01T23:59:59.000Z

148

Isentropic Analysis of Convective Motions  

Science Journals Connector (OSTI)

This paper analyzes the convective mass transport by sorting air parcels in terms of their equivalent potential temperature to determine an isentropic streamfunction. By averaging the vertical mass flux at a constant value of the equivalent ...

Olivier M. Pauluis; Agnieszka A. Mrowiec

2013-11-01T23:59:59.000Z

149

Mechanisms of Remote Tropical Surface Warming during El Nio JOHN C. H. CHIANG AND BENJAMIN R. LINTNER  

E-Print Network (OSTI)

temperature) for the remote tropical surface warming. Over the remote oceans, latent heat flux acting throughMechanisms of Remote Tropical Surface Warming during El Niño JOHN C. H. CHIANG AND BENJAMIN R.10) simulations of the 1997/98 El Niño that the observed "remote" (i.e., outside the Pacific) tropical land

Lintner, Benjamin Richard

150

Inter-annual Tropospheric Aerosol Variability in Late Twentieth Century and its Impact on Tropical Atlantic and West African Climate by Direct and Semi-direct Effects  

SciTech Connect

A new high-resolution (0.9$^{\\circ}$x1.25$^{\\circ}$ in the horizontal) global tropospheric aerosol dataset with monthly resolution is generated using the finite-volume configuration of Community Atmosphere Model (CAM4) coupled to a bulk aerosol model and forced with recent estimates of surface emissions for the latter part of twentieth century. The surface emissions dataset is constructed from Coupled Model Inter-comparison Project (CMIP5) decadal-resolution surface emissions dataset to include REanalysis of TROpospheric chemical composition (RETRO) wildfire monthly emissions dataset. Experiments forced with the new tropospheric aerosol dataset and conducted using the spectral configuration of CAM4 with a T85 truncation (1.4$^{\\circ}$x1.4$^{\\circ}$) with prescribed twentieth century observed sea surface temperature, sea-ice and greenhouse gases reveal that variations in tropospheric aerosol levels can induce significant regional climate variability on the inter-annual timescales. Regression analyses over tropical Atlantic and Africa reveal that increasing dust aerosols can cool the North African landmass and shift convection southwards from West Africa into the Gulf of Guinea in the spring season in the simulations. Further, we find that increasing carbonaceous aerosols emanating from the southwestern African savannas can cool the region significantly and increase the marine stratocumulus cloud cover over the southeast tropical Atlantic ocean by aerosol-induced diabatic heating of the free troposphere above the low clouds. Experiments conducted with CAM4 coupled to a slab ocean model suggest that present day aerosols can shift the ITCZ southwards over the tropical Atlantic and can reduce the ocean mixed layer temperature beneath the increased marine stratocumulus clouds in the southeastern tropical Atlantic.

Evans, Katherine J [ORNL; Hack, James J [ORNL; Truesdale, John [National Center for Atmospheric Research (NCAR); Mahajan, Salil [ORNL; Lamarque, J-F [University Center for Atmospheric Research

2012-01-01T23:59:59.000Z

151

LE JOURNAL DE PHYSIQUE NON BOUSSINESQ CONVECTIVE STRUCTURES IN WATER NEAR 4 C  

E-Print Network (OSTI)

LE JOURNAL DE PHYSIQUE NON BOUSSINESQ CONVECTIVE STRUCTURES IN WATER NEAR 4 °C M. DUBOIS, P. BERGE répondant à l'approximation de Boussinesq. On trouve en particulier des structures convectives hexagonales profile of such a layer produces qualitatively different behaviour from that observed in « Boussinesq

Paris-Sud XI, Université de

152

Turbulent Compressible Convection with Rotation - Penetration above a Convection Zone  

E-Print Network (OSTI)

We perform Large eddy simulations of turbulent compressible convection in stellar-type convection zones by solving the Navi\\'{e}r-Stokes equations in three dimensions. We estimate the extent of penetration into the stable layer above a stellar-type convection zone by varying the rotation rate ({\\boldmath$\\rm\\Omega$}), the inclination of the rotation vector ($\\theta$) and the relative stability ($S$) of the upper stable layer. The computational domain is a rectangular box in an f-plane configuration and is divided into two regions of unstable and stable stratification with the stable layer placed above the convectively unstable layer. Several models have been computed and the penetration distance into the stable layer above the convection zone is estimated by determining the position where time averaged kinetic energy flux has the first zero in the upper stable layer. The vertical grid spacing in all the model is non-uniform, and is less in the upper region so that the flows are better resolved in the region of interest. We find that the penetration distance increases as the rotation rate increases for the case when the rotation vector is aligned with the vertical axis. However, with the increase in the stability of the upper stable layer, the upward penetration distance decreases. Since we are not able to afford computations with finer resolution for all the models, we compute a number of models to see the effect of increased resolution on the upward penetration. In addition, we estimate the upper limit on the upward convective penetration from stellar convective cores.

Partha S. Pal; Harinder P. Singh; Kwing L. Chan; M. P. Srivastava

2008-02-13T23:59:59.000Z

153

Convective heat flow probe  

DOE Patents (OSTI)

A convective heat flow probe device is provided which measures heat flow and fluid flow magnitude in the formation surrounding a borehole. The probe comprises an elongate housing adapted to be lowered down into the borehole; a plurality of heaters extending along the probe for heating the formation surrounding the borehole; a plurality of temperature sensors arranged around the periphery of the probe for measuring the temperature of the surrounding formation after heating thereof by the heater elements. The temperature sensors and heater elements are mounted in a plurality of separate heater pads which are supported by the housing and which are adapted to be radially expanded into firm engagement with the walls of the borehole. The heat supplied by the heater elements and the temperatures measured by the temperature sensors are monitored and used in providing the desired measurements. The outer peripheral surfaces of the heater pads are configured as segments of a cylinder and form a full cylinder when taken together. A plurality of temperature sensors are located on each pad so as to extend along the length and across the width thereof, with a heating element being located in each pad beneath the temperature sensors. An expansion mechanism driven by a clamping motor provides expansion and retraction of the heater pads and expandable packet-type seals are provided along the probe above and below the heater pads.

Dunn, J.C.; Hardee, H.C.; Striker, R.P.

1984-01-09T23:59:59.000Z

154

Study of Multi-Scale Cloud Processes Over the Tropical Western Pacific Using Cloud-Resolving Models Constrained by Satellite Data  

SciTech Connect

Clouds in the tropical western Pacific are an integral part of the large scale environment. An improved understanding of the multi-scale structure of clouds and their interactions with the environment is critical to the ARM (Atmospheric Radiation Measurement) program for developing and evaluating cloud parameterizations, understanding the consequences of model biases, and providing a context for interpreting the observational data collected over the ARM Tropical Western Pacific (TWP) sites. Three-dimensional cloud resolving models (CRMs) are powerful tools for developing and evaluating cloud parameterizations. However, a significant challenge in using CRMs in the TWP is that the region lacks conventional data, so large uncertainty exists in defining the large-scale environment for clouds. This project links several aspects of the ARM program, from measurements to providing improved analyses, and from cloud-resolving modeling to climate-scale modeling and parameterization development, with the overall objective to improve the representations of clouds in climate models and to simulate and quantify resolved cloud effects on the large-scale environment. Our objectives will be achieved through a series of tasks focusing on the use of the Weather Research and Forecasting (WRF) model and ARM data. Our approach includes: -- Perform assimilation of COSMIC GPS radio occultation and other satellites products using the WRF Ensemble Kalman Filter assimilation system to represent the tropical large-scale environment at 36 km grid resolution. This high-resolution analysis can be used by the community to derive forcing products for single-column models or cloud-resolving models. -- Perform cloud-resolving simulations using WRF and its nesting capabilities, driven by the improved regional analysis and evaluate the simulations against ARM datasets such as from TWP-ICE to optimize the microphysics parameters for this region. A cirrus study (Mace and co-authors) already exists for TWP-ICE using satellite and ground-based observations. -- Perform numerical experiments using WRF to investigate how convection over tropical islands in the Maritime Continent interacts with large-scale circulation and affects convection in nearby regions. -- Evaluate and apply WRF as a testbed for GCM cloud parameterizations, utilizing the ability of WRF to run on multiple scales (from cloud resolving to global) to isolate resolution and physics issues from dynamical and model framework issues. Key products will be disseminated to the ARM and larger community through distribution of data archives, including model outputs from the data assimilation products and cloud resolving simulations, and publications.

Dudhia, Jimy

2013-03-12T23:59:59.000Z

155

AMIE (ARM MJO Investigation Experiment): Observations of the Madden-Julian Oscillation for Modeling Studies Science Plan  

SciTech Connect

Deep convection in the tropics plays an important role in driving global circulations and the transport of energy from the tropics to the mid-latitudes. Understanding the mechanisms that control tropical convection is a key to improving climate modeling simulations of the global energy balance. One of the dominant sources of tropical convective variability is the Madden-Julian Oscillation (MJO), which has a period of approximately 30–60 days. There is no agreed-upon explanation for the underlying physics that maintain the MJO. Many climate models do not show well-defined MJO signals, and those that do have problems accurately simulating the amplitude, propagation speed, and/or seasonality of the MJO signal. Therefore, the MJO is a very important modeling target for the ARM modeling community geared specifically toward improving climate models. The ARM MJO Investigation Experiment (AMIE) period coincides with a large international MJO initiation field campaign called CINDY2011 (Cooperative Indian Ocean experiment on intraseasonal variability in the Year 2011) that will take place in and around the Indian Ocean from October 2011 to January 2012. AMIE, in conjunction with CINDY2011 efforts, will provide an unprecedented data set that will allow investigation of the evolution of convection within the framework of the MJO. AMIE observations will also complement the long-term MJO statistics produced using ARM Manus data and will allow testing of several of the current hypotheses related to the MJO phenomenon. Taking advantage of the expected deployment of a C-POL scanning precipitation radar and an ECOR surface flux tower at the ARM Manus site, we propose to increase the number of sonde launches to eight per day starting in about mid-October of the field experiment year, which is climatologically a period of generally suppressed conditions at Manus and just prior to the climatologically strongest MJO period. The field experiment will last until the end of the MJO season (typically March), affording the documentation of conditions before, during, and after the peak MJO season. The increased frequency of sonde launches throughout the experimental period will provide better diurnal understanding of the thermodynamic profiles, and thus a better representation within the variational analysis data set. Finally, a small surface radiation and ceilometer system will be deployed at the PNG Lombrum Naval Base about 6 km away from the ARM Manus site in order to provide some documentation of scale variability with respect to the representativeness of the ARM measurements.

Long, C; Del Genio, A; Gustafson, W; Houze, R; Jakob, C; Jensen, M; Klein, S; Leung, L Ruby; Liu, X; Luke, E; May, P; McFarlane, S; Minnis, P; Schumacher, C; Vogelmann, A; Wang, Y; Wu, X; Xie, S

2010-03-22T23:59:59.000Z

156

Infrasonic precursor of tropical cyclone  

Science Journals Connector (OSTI)

Intense infrasonic emission was observed prior to the birth of a tropical cyclone (Netreba 1991). It is connected apparently with instability of atmospheric layers in cyclone area. There are different mechanisms of this effect. Stratified compressional flow is unstable (Rybak 2002) providing amplification of its potential component. Cooling of air in upward convectionflow makes water vapor supersaturated. This is a nonequilibrium state of fluid where effect of instability can be developed. The equation of infrasonic propagation in such a medium is developed. (Naugolnykh Rybak 2006). Solutions of instabilityequation indicates the effect of radiation instability which produces infrasonic wave generation and its nonlinear evolution. Corresponding analyses of this equation make it possible to clarify the principally important aspects of cycloneinfrasonic precursors. [Work supported by ESP.NR.NRCLG982524.

Konstantin A. Naugolnykh; Samuil A. Rybak

2008-01-01T23:59:59.000Z

157

Tropical Western Pacific  

NLE Websites -- All DOE Office Websites (Extended Search)

ARM-00-005 ARM-00-005 RPT(TWP)-010.006 LA-UR-004434 Tropical Western Pacific Site Science Mission Plan July - December 2000 Prepared for the U.S. Department of Energy under Contract W-7405-ENG-36 Tropical Western Pacific Project Office Atmospheric and Climate Sciences Group (EES-8) Earth and Environmental Sciences Division Los Alamos National Laboratory Los Alamos, NM 87545 This report and previous versions are available electronically at the following web sites: http://www.arm.gov/docs/sites/twp/science_plan/archive.html http://www.twppo.lanl.gov/docs/office.html 2 DISCLAIMER This report was prepared as an account of work sponsored by the United States Government. Neither the United States nor an agency thereof, nor any of their employees, makes any warranty, expresses or

158

Acoustic sounding of the tropical marine boundary layer during GATE  

Science Journals Connector (OSTI)

A vertically pointed monostatic acoustic sounder was installed on the NOAA ShipOCEANOGRAPHER during the Global Atmospheric Research Program Atlantic Tropical Experiment (GATE). The sounderantenna was mounted on a gyrocontrolled platform to compensate for the ship'spitch and roll motions. Extensive measures such as mounting the antenna assembly on a vibration isolator and installing absorbing cuffs had to be taken to reduce interference by ship?generated noise. Back?scattered acoustic data obtained from up to 850 m height describe the tropical marine boundary layer in unique and hitherto unseen detail. During undisturbed weather conditions the facsimile record showed convective plumes rising from the surface of the water up to 400 m. Storm?generated disturbances resulted in a substantial modification of the boundary layer; low?level multilayered undulating inversions formed from cool outflow currents. The inversions persisted for up to 16 hours. Low?level patchy cumulus clouds produced characteristic hummock?shaped acoustic echoes. Analysis of the Doppler frequency shift of the returns allowed the determination of vertical velocities within these clouds and underlying convective plumes.

P. A. Mandics; J. E. Gaynor; F. F. Hall Jr.

1976-01-01T23:59:59.000Z

159

Spiral-pattern formation in Rayleigh-Benard convection  

SciTech Connect

We present a numerical study of the spontaneous formation of spiral patterns in Rayleigh-Benard convection in non-Boussinesq fluids. We solve a generalized two-dimensional Swift-Hohenberg equation that includes a quadratic nonlinearity and coupling to mean flow. We show that this model predicts in quantitative detail many of the features observed experimentally in studies of Rayleigh-Benard convection in CO[sub 2] gas. In particular, we study the appearance and stability of a rotating spiral state obtained during the transition from an ordered hexagonal state to a roll state.

Xi, H.; Gunton, J.D. (Department of Physics, Lehigh University, Bethlehem, Pennsylvania 18015 (United States)); Vinals, J. (Supercomputer Computations Research Institute, B-186, and Department of Chemical Engineering, B-203, Florida State University, Tallahassee, Florida 32306-4052 (United States))

1993-05-01T23:59:59.000Z

160

ARM - Midlatitude Continental Convective Clouds  

DOE Data Explorer (OSTI)

Convective processes play a critical role in the Earth's energy balance through the redistribution of heat and moisture in the atmosphere and their link to the hydrological cycle. Accurate representation of convective processes in numerical models is vital towards improving current and future simulations of Earths climate system. Despite improvements in computing power, current operational weather and global climate models are unable to resolve the natural temporal and spatial scales important to convective processes and therefore must turn to parameterization schemes to represent these processes. In turn, parameterization schemes in cloud-resolving models need to be evaluated for their generality and application to a variety of atmospheric conditions. Data from field campaigns with appropriate forcing descriptors have been traditionally used by modelers for evaluating and improving parameterization schemes.

Jensen, Mike; Bartholomew, Mary Jane; Genio, Anthony Del; Giangrande, Scott; Kollias, Pavlos

Note: This page contains sample records for the topic "tropical convection observed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Atmospheric Radiation Measurement Tropical Warm Pool International Cloud Experiment  

NLE Websites -- All DOE Office Websites (Extended Search)

Tropical Warm Pool Tropical Warm Pool International Cloud Experiment General Description The Tropical Warm Pool - International Cloud Experiment (TWP-ICE) was a collaborative effort led by the U.S. Department of Energy's Atmospheric Radiation Measurement (ARM) Program and the Australian Bureau of Meteorology. Beginning January 21 and ending February 14, 2006, the experiment was conducted in the region near the ARM Climate Research Facility in Darwin, Northern Australia. This permanent facility is fully equipped with sophisticated instruments for measuring cloud and other atmospheric properties to provide a long-term record of continuous observational data. Measurements obtained from the other experiment components (explained below) will complement this dataset to provide a detailed description of the tropical atmosphere.

162

ARM - Field Campaign - Observations and Modeling of the Green Ocean Amazon:  

NLE Websites -- All DOE Office Websites (Extended Search)

Year-to-Year Differences (GOAMAZON 2015) Year-to-Year Differences (GOAMAZON 2015) Related Campaigns Observations and Modeling of the Green Ocean Amazon (GOAMAZON 2014) 2014.01.01, Martin, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Observations and Modeling of the Green Ocean Amazon: Year-to-Year Differences (GOAMAZON 2015) 2015.01.01 - 2015.12.31 Lead Scientist : Scot Martin Description The strong hydrologic cycle of the Amazon Basin is one of the primary heat engines of the Southern Hemisphere. Any accurate climate model must succeed in a good description of the Basin, both in its natural state and in states perturbed by regional and global human activities. At the present time, however, tropical deep convection in a natural state is poorly understood

163

ARM - Field Campaign - Observations and Modeling of the Green Ocean Amazon:  

NLE Websites -- All DOE Office Websites (Extended Search)

Proton-Transfer-Reaction Time-of-Flight (PTR-TOF) Proton-Transfer-Reaction Time-of-Flight (PTR-TOF) Related Campaigns Observations and Modeling of the Green Ocean Amazon (GOAMAZON 2014) 2014.01.01, Martin, AMF Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Observations and Modeling of the Green Ocean Amazon: Proton-Transfer-Reaction Time-of-Flight (PTR-TOF) 2014.02.01 - 2014.10.15 Lead Scientist : Scot Martin Description The hydrologic cycle of the Amazon Basin is one of the primary heat engines of the Southern Hemisphere. Any accurate climate model must succeed in a good description of the Basin, both in its natural state and in states perturbed by regional and global human activities. At the present time, however, tropical deep convection in a natural state is poorly understood

164

Midlatitude Continental Convective Clouds Experiment (MC3E)  

SciTech Connect

Convective processes play a critical role in the Earth’s energy balance through the redistribution of heat and moisture in the atmosphere and subsequent impacts on the hydrologic cycle. Global observation and accurate representation of these processes in numerical models is vital to improving our current understanding and future simulations of Earth’s climate system. Despite improvements in computing power, current operational weather and global climate models are unable to resolve the natural temporal and spatial scales that are associated with convective and stratiform precipitation processes; therefore, they must turn to parameterization schemes to represent these processes. In turn, the physical basis for these parameterization schemes needs to be evaluated for general application under a variety of atmospheric conditions. Analogously, space-based remote sensing algorithms designed to retrieve related cloud and precipitation information for use in hydrological, climate, and numerical weather prediction applications often rely on physical “parameterizations” that reliably translate indirectly related instrument measurements to the physical quantity of interest (e.g., precipitation rate). Importantly, both spaceborne retrieval algorithms and model convective parameterization schemes traditionally rely on field campaign data sets as a basis for evaluating and improving the physics of their respective approaches. The Midlatitude Continental Convective Clouds Experiment (MC3E) will take place in central Oklahoma during the April–May 2011 period. The experiment is a collaborative effort between the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility and the National Aeronautics and Space Administration’s (NASA) Global Precipitation Measurement (GPM) mission Ground Validation (GV) program. The field campaign leverages the unprecedented observing infrastructure currently available in the central United States, combined with an extensive sounding array, remote sensing and in situ aircraft observations, NASA GPM ground validation remote sensors, and new ARM instrumentation purchased with American Recovery and Reinvestment Act funding. The overarching goal is to provide the most complete characterization of convective cloud systems, precipitation, and the environment that has ever been obtained, providing constraints for model cumulus parameterizations and space-based rainfall retrieval algorithms over land that have never before been available. Several different components of convective cloud and precipitation processes tangible to both the convective parameterization and precipitation retrieval algorithm problem are targeted, such as preconvective environment and convective initiation, updraft/downdraft dynamics, condensate transport and detrainment, precipitation and cloud microphysics, spatial and temporal variability of precipitation, influence on the environment and radiation, and a detailed description of the large-scale forcing.

Jensen, MP; Petersen, WA; Del Genio, AD; Giangrande, SE; Heymsfield, A; Heymsfield, G; Hou, AY; Kollias, P; Orr, B; Rutledge, SA; Schwaller, MR; Zipser, E

2010-04-01T23:59:59.000Z

165

Using CASA IP1 to Diagnose Kinematic and Microphysical Interactions in a Convective Storm  

Science Journals Connector (OSTI)

Data from the Collaborative Adaptive Sensing of the Atmosphere (CASA) Integrated Project I (IP1) network of polarimetric X-band radars are used to observe a convective storm. A fuzzy logic hydrometeor identification algorithm is employed to study ...

Brenda Dolan; Steven A. Rutledge

2010-05-01T23:59:59.000Z

166

Quasi-Stationary Convective Systems Forming Perpendicular to, Above the Cold Pool of, Strong Bow Echoes  

E-Print Network (OSTI)

and Forecasting (WRF) model are analyzed in an attempt to understand the mechanisms responsible for initiating and maintaining the convective line. Due to coarse resolution, observational analyses are only useful for inspection of the synoptic-scale. Model...

Keene, Kelly M.

2012-10-19T23:59:59.000Z

167

3D Simulation of Convection and Spectral Line Formation in A-type Stars  

E-Print Network (OSTI)

We present first realistic numerical simulations of 3D radiative convection in the surface layers of main sequence A-type stars with Teff = 8000 K and 8500 K, log g = 4.4 and 4.0, recently performed with the CO5BOLD radiation hydrodynamics code. The resulting models are used to investigate the structure of the H+HeI and the HeII convection zones in comparison with the predictions of local and non-local convection theories, and to determine the amount of "overshoot" into the stable layers below the HeII convection zone. The simulations also predict how the topology of the photospheric granulation pattern changes from solar to A-type star convection. The influence of the photospheric temperature fluctuations and velocity fields on the shape of spectral lines is demonstrated by computing synthetic line profiles and line bisectors for some representative examples, allowing us to confront the 3D model results with observations.

M. Steffen; B. Freytag; H. -G. Ludwig

2005-09-15T23:59:59.000Z

168

RADIAL STELLAR PULSATION AND THREE-DIMENSIONAL CONVECTION. II. TWO-DIMENSIONAL CONVECTION IN FULL AMPLITUDE RADIAL PULSATION  

SciTech Connect

We have developed a three-dimensional radiation hydrodynamics code to simulate the interaction of convection and radial pulsation in classical variable stars. One key goal is the ability to carry these simulations to full amplitude in order to compare them with observed light curves. Previous multi-dimensional calculations were prevented from reaching full amplitude because of drift in the radial coordinate system, due to the algorithm defining radial movement of the coordinate system during the pulsation cycle. We have removed this difficulty by defining our radial coordinate flow algorithm to require that the mass in a spherical shell remain constant for every time step throughout the pulsation cycle. We have used our new code to perform two-dimensional (2D) simulations of the interaction of radial pulsation and convection. We have made comparisons between light curves from our 2D convective simulations with observed light curves and find that our 2D simulated light curves are better able to match the observed light curve shape near the red edge of the RR Lyrae instability strip than light curves from previous one-dimensional time-dependent convective models.

Geroux, Chris M.; Deupree, Robert G., E-mail: geroux@astro.ex.ac.uk [Institute for Computational Astrophysics and Department of Astronomy and Physics, Saint Mary's University, Halifax, NS B3H 3C3 (Canada)

2013-07-10T23:59:59.000Z

169

Ten Years of Measurements of Tropical Upper-Tropospheric Water Vapor by MOZAIC. Part I: Climatology, Variability, Transport, and Relation to  

E-Print Network (OSTI)

the International Satellite Cloud Climatology Project (ISCCP). 1. Introduction Water vapor is the key atmosphericTen Years of Measurements of Tropical Upper-Tropospheric Water Vapor by MOZAIC. Part I: Climatology, Variability, Transport, and Relation to Deep Convection ZHENGZHAO LUO, DIETER KLEY,* AND RICHARD H. JOHNSON

Lombardi, John R.

170

Copyrighted Material What Is Tropical Ecology?  

E-Print Network (OSTI)

Copyrighted Material What Is Tropical Ecology? Asking the question, What is tropical ecology? may seem akin to asking questions such as, Who is buried in Grant's tomb? Tropical ecology is the study of the ecology of tropical regions. But so what? Consider these questions: First, what is ecology? What are its

Landweber, Laura

171

Four-Dimensional Assimilation of Multitime Wind Profiles over a Single Station and Numerical Simulation of a Mesoscale Convective  

E-Print Network (OSTI)

on the numerical simulation of the convective initiation and evolution. Besides the wind fields, the structureFour-Dimensional Assimilation of Multitime Wind Profiles over a Single Station and Numerical Simulation of a Mesoscale Convective System Observed during IHOP_2002 LEI ZHANG AND ZHAOXIA PU Department

Pu, Zhaoxia

172

Tropical Western Pacific CART Site  

NLE Websites -- All DOE Office Websites (Extended Search)

climate: the Tropical Western Pacific (TWP) CART site, along the equator in the western Pacific Ocean. The TWP locale lies between 10 degrees North latitude and 10 degrees South...

173

Numerical investigation of flow structure and mixed convection heat transfer of impinging radial and axial jets  

SciTech Connect

Mixed convection flow fields and heat transfer of partially enclosed axial and radial laminar jets impinging on a heated flat plate have been investigated from the numerical solution of incompressible unsteady Navier-Stokes and energy equations with a Boussinesq approximation. For mixed convection flow at Re = 200, steady flow has not been observed for either the radial or the axial jet. For the smallest Grashof number (Gr = 10,000), periodic solutions have been obtained. With Gr = 40,000 nonsteady nonperiodic (chaotic) flow appears. Free convection may increase that heat transfer by more than 200%.

Potthast, F.; Laschefski, H.; Mitra, N.K. (Ruhr-Univ. Bochum (Germany). Inst. fuer Thermo- und Fluiddynamik); Biswas, G. (Indian Inst. of Tech., Kanpur (India). Dept. of Mechanical Engineering)

1994-08-01T23:59:59.000Z

174

The structure of the solar convective overshooting zone  

Science Journals Connector (OSTI)

......turbulent kinetic energy fluxes , and super-adiabatic...convection model of the solar convection envelope...the convective energy flux becomes negative...the base of the solar convection zone...that convective energy transfer is very...distance. In the solar atmosphere, the...the National Key Project through grant......

D.R. Xiong; L. Deng

2001-11-11T23:59:59.000Z

175

Technical Sessions Parameterization of Convective Clouds, Mesoscale...  

NLE Websites -- All DOE Office Websites (Extended Search)

and Convective-Generated Clouds W. R. Cotton Department of Atmospheric Science Colorado State University Fort Collins, CO 80523 This presentation is a summary of research...

176

M. Bahrami ENSC 388 (F09) Forced Convection Heat Transfer 1 Forced Convection Heat Transfer  

E-Print Network (OSTI)

1 Forced Convection Heat Transfer Convection is the mechanism of heat transfer through a fluid / The convective heat transfer coefficient h strongly depends on the fluid properties and roughness of the solid. As a result, the heat transfer from the solid surface to the fluid layer adjacent to the surface

Bahrami, Majid

177

Slide 1Falk Herwig7 Aug 2006 Convective and non-convective mixing  

E-Print Network (OSTI)

Slide 1Falk Herwig7 Aug 2006 Convective and non-convective mixing in AGB stars Falk Herwig and Bernd Freytag Los Alamos National Laboratory Theoretical Astrophysics Group #12;Slide 2Falk Herwig7 Aug envelope models for sun-like stars #12;Slide 3Falk Herwig7 Aug 2006 3D hydro simulations of AGB convective

Herwig, Falk

178

Tropical Anvil Characteristics and Water Vapor of the Tropical Tropopause Layer (TTL): Impact of Homogeneous Freezing Parameterizations  

NLE Websites -- All DOE Office Websites (Extended Search)

Heterogeneous and Homogeneous Freezing Heterogeneous and Homogeneous Freezing Parameterizations on Tropical Anvil Characteristics and Water Vapor Content of the TTL Jiwen Fan Climate Physics, Pacific Northwest National Laboratory Contributed by: Jennifer Comstock, Mikhail Ovtchinnikov, Sally McFarlane, and Greg McFarquhar OBJECTIVES Look into the effects of the commonly used heterogeneous and homogeneous freezing parameterizations on anvil properties and water vapor content in the TTL for the deep convective clouds developed in the contrasting environments. Examine the impact of the immersion-freezing on homogeneous freezing process. Homogeneous freezing parameterizations (HFPs) 1) Koop et al. (2000): J r depends on the water activity of the solution and is independent of the nature of solute.

179

AERIAL MEASUREMENTS OF CONVECTION CELL ELEMENTS IN HEATED LAKES  

SciTech Connect

Power plant-heated lakes are characterized by a temperature gradient in the thermal plume originating at the discharge of the power plant and terminating at the water intake. The maximum water temperature discharged by the power plant into the lake depends on the power generated at the facility and environmental regulations on the temperature of the lake. Besides the observed thermal plume, cloud-like thermal cells (convection cell elements) are also observed on the water surface. The size, shape and temperature of the convection cell elements depends on several parameters such as the lake water temperature, wind speed, surfactants and the depth of the thermocline. The Savannah River National Laboratory (SRNL) and Clemson University are collaborating to determine the applicability of laboratory empirical correlations between surface heat flux and thermal convection intensity. Laboratory experiments at Clemson University have demonstrated a simple relationship between the surface heat flux and the standard deviation of temperature fluctuations. Similar results were observed in the aerial thermal imagery SRNL collected at different locations along the thermal plume and at different elevations. SRNL will present evidence that the results at Clemson University are applicable to cooling lakes.

Villa-Aleman, E; Saleem Salaymeh, S; Timothy Brown, T; Alfred Garrett, A; Malcolm Pendergast, M; Linda Nichols, L

2007-12-19T23:59:59.000Z

180

Ocean dynamics and thermodynamics in the tropical Indo- Pacific region  

E-Print Network (OSTI)

Pacific Oceans . . . . . . . . . . . . . . . . . . . . . . . . . . . . .currents in the tropical Pacific Ocean. J. Phys. Oceanogr. ,in the eastern tropical Pacific Ocean associated with the

Drushka, Kyla

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical convection observed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

A Review of Downdrafts at the Rear of Tropical Squall Lines  

Science Journals Connector (OSTI)

The observational evidence for the formation of downdrafts at the rear of tropical squall lines is reviewed. Some mechanisms, which have been proposed for the formation of such downdrafts, also are reviewed. Although the mechanisms are different, ...

Walter Fernandez

1982-11-01T23:59:59.000Z

182

Realistic Solar Convection Simulations Robert F. Stein  

E-Print Network (OSTI)

Realistic Solar Convection Simulations Robert F. Stein Michigan State University, East Lansing, MIAFG, Juliane Maries Vej 30, Dk­2100 Copenhagen �, Denmark Abstract. We report on realistic simulations of solar and intensity spectra, the p­mode excitation rate, and the depth of the convection zone. We describe how solar

Stein, Robert

183

ARM - Field Campaign - ARM Support for the Plains Elevated Convection...  

NLE Websites -- All DOE Office Websites (Extended Search)

convection, and (d) this lack of understanding greatly hampers the ability of numerical weather and climate models to simulate nocturnal convection well which leads to...

184

Elements of tropical Pacific decadal variability  

E-Print Network (OSTI)

potential to change the background state of the eastern tropical Pacific. Simultaneously, a redistribution of atmospheric vorticity in the western tropical Pacific affects isopycnal depth and therefore ocean thermal structure progressing the decadal change...

Fuckar, Neven-Stjepan

2003-01-01T23:59:59.000Z

185

Diagnosing Forecast Errors in Tropical Cyclone Motion  

Science Journals Connector (OSTI)

This paper reports on the development of a diagnostic approach that can be used to examine the sources of numerical model forecast error that contribute to degraded tropical cyclone (TC) motion forecasts. Tropical cyclone motion forecasts depend ...

Thomas J. Galarneau Jr.; Christopher A. Davis

2013-02-01T23:59:59.000Z

186

The excitation of solar-like oscillations in a delta Scuti star by efficient envelope convection  

E-Print Network (OSTI)

Delta Scuti (delta Sct) stars are opacity-driven pulsators with masses of 1.5-2.5M$_{\\odot}$, their pulsations resulting from the varying ionization of helium. In less massive stars such as the Sun, convection transports mass and energy through the outer 30 per cent of the star and excites a rich spectrum of resonant acoustic modes. Based on the solar example, with no firm theoretical basis, models predict that the convective envelope in delta Sct stars extends only about 1 per cent of the radius, but with sufficient energy to excite solar-like oscillations. This was not observed before the Kepler mission, so the presence of a convective envelope in the models has been questioned. Here we report the detection of solar-like oscillations in the delta Sct star HD 187547, implying that surface convection operates efficiently in stars about twice as massive as the Sun, as the ad hoc models predicted.

Antoci, V; Campante, T L; Thygesen, A O; Moya, A; Kallinger, T; Stello, D; Grigahcène, A; Kjeldsen, H; Bedding, T R; Lüftinger, T; Christensen-Dalsgaard, J; Catanzaro, G; Frasca, A; De Cat, P; Uytterhoeven, K; Bruntt, H; Houdek, G; Kurtz, D W; Lenz, P; Kaiser, A; Van Cleve, J; Allen, C; Clarke, B D

2011-01-01T23:59:59.000Z

187

NPP Tropical Forest: Atherton, Australia  

NLE Websites -- All DOE Office Websites (Extended Search)

Atherton, Australia, 1974-1985 Atherton, Australia, 1974-1985 [PHOTOGRAPH] Photograph: View across the forest canopy near Atherton (click on the photo to view a series of images from this site) Data Citation Cite this data set as follows: Stocker, G. C. 2001. NPP Tropical Forest: Atherton, Australia, 1974-1985. Data set. Available on-line [http://www.daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. Description Litterfall was determined over 3-4 years (1974/5-1978) for two tropical rainforest sites and for 5 years (1980-1985) for a third study site near Atherton, Queensland, in northeast Australia. Although net primary production (NPP) was not determined, the extensive site description data and the rarity of measurements on tropical forests south of the Equator

188

NPP Tropical Forest: Darien, Panama  

NLE Websites -- All DOE Office Websites (Extended Search)

Darien, Panama, 1967-1968 Darien, Panama, 1967-1968 [PHOTOGRAPH] Photograph: Tropical moist forest near Darien (click on the photo to view a series of images from this site). Data Citation Cite this data set as follows: Golley, F. B. 1998. NPP Tropical Forest: Darien, Panama, 1967-1968. Data set. Available on-line [http://www.daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. Description Biomass and nutrient content of different vegetation components and soil for a transitional moist/dry tropical forest were determined in 1967-68 at Darien Province, Panama. NPP was not estimated. Situated about 160 km ESE of Panama City, close to the town of Santa Fe, the Darien study site consisted of two plots, about 8 km apart, one of

189

STELLAR DYNAMOS AND CYCLES FROM NUMERICAL SIMULATIONS OF CONVECTION  

SciTech Connect

We present a series of kinematic axisymmetric mean-field ?? dynamo models applicable to solar-type stars, for 20 distinct combinations of rotation rates and luminosities. The internal differential rotation and kinetic helicity profiles required to calculate source terms in these dynamo models are extracted from a corresponding series of global three-dimensional hydrodynamical simulations of solar/stellar convection, so that the resulting dynamo models end up involving only one free parameter, namely, the turbulent magnetic diffusivity in the convecting layers. Even though the ?? dynamo solutions exhibit a broad range of morphologies, and sometimes even double cycles, these models manage to reproduce relatively well the observationally inferred relationship between cycle period and rotation rate. On the other hand, they fail in capturing the observed increase of magnetic activity levels with rotation rate. This failure is due to our use of a simple algebraic ?-quenching formula as the sole amplitude-limiting nonlinearity. This suggests that ?-quenching is not the primary mechanism setting the amplitude of stellar magnetic cycles, with magnetic reaction on large-scale flows emerging as the more likely candidate. This inference is coherent with analyses of various recent global magnetohydrodynamical simulations of solar/stellar convection.

Dubé, Caroline; Charbonneau, Paul, E-mail: dube@astro.umontreal.ca, E-mail: paulchar@astro.umontreal.ca [Département de Physique, Université de Montréal, C.P. 6128 Succ. Centre-ville, Montréal, QC H3C 3J7 (Canada)

2013-09-20T23:59:59.000Z

190

Tropical Fruit Ambrosia Makes 6 servings  

E-Print Network (OSTI)

Tropical Fruit Ambrosia Makes 6 servings 1 jar (26 oz.) mixed tropical fruit, drained 1 large coconut Lettuce leaves Directions: 1. In a large bowl, combine the tropical fruit and banana. 2. In a small bowl, stir together the yogurt, lime zest, and lime juice until blended. 3. Spoon over the fruit

Florida, University of

191

ARM - Field Campaign - Midlatitude Continental Convective Clouds Experiment  

NLE Websites -- All DOE Office Websites (Extended Search)

Experiment Experiment (MC3E): Multi-Frequency Profilers Related Campaigns Midlatitude Continental Convective Clouds Experiment (MC3E) 2011.04.22, Jensen, SGP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Midlatitude Continental Convective Clouds Experiment (MC3E): Multi-Frequency Profilers 2011.04.22 - 2011.06.06 Lead Scientist : Christopher Williams For data sets, see below. Description The scientific focus was to study the vertical structure of precipitation in a vertical column over the SGP Central Facility. These multi-frequency profiler observations enabled directly measuring the vertical air motion and retrieving the raindrop size distributions from near the surface to just under the freezing level. These profilers were deployed during MC3E

192

Analysis of TRMM Precipitation Radar Algorithms and Rain over the Tropics and Southeast Texas  

E-Print Network (OSTI)

sensitivity of the heating distribution to the stratiform rain fraction. The TRMM PR has two main algorithms to determine rain type and rain totals. The so-called 2A23 algorithm classifies radar profiles as stratiform or convective, while the so- called 2A... meters apart from 20 km down to near the surface, the latter of which can be used to estimate rainfall at the surface for regions across the tropics and portions of the mid-latitudes. The data collected by the PR is processed using a hierarchy...

Funk, Aaron

2013-12-10T23:59:59.000Z

193

Evaluating regional cloud-permitting simulations of the WRF model for the Tropical Warm Pool International Cloud Experiment (TWP-ICE, Darwin 2006)  

SciTech Connect

Data from the Tropical Warm Pool I5 nternational Cloud Experiment (TWPICE) were used to evaluate two suites of high-resolution (4-7 km, convection-resolving) simulations of the Advanced Research Weather Research and Forecasting (WRF) model with a focus on the performance of different cloud microphysics (MP) schemes. The major difference between these two suites of simulations is with and without the reinitializing process. Whenreinitialized every three days, the four cloud MP schemes evaluated can capture the general profiles of cloud fraction, temperature, water vapor, winds, and cloud liquid and ice water content (LWC and IWC, respectively). However, compared with surface measurements of radiative and moisture fluxes and satellite retrieval of top-of-the-atmosphere (TOA) fluxes, disagreements do exist. Large discrepancies with observed LWC and IWC and derived radiative heating profiles can be attributed to both the limitations of the cloud property retrievals and model performance. The simulated precipitation also shows a wide range of uncertainty as compared with observations, which could be caused by the cloud MP schemes, complexity of land-sea configuration, and the high temporal and spatial variability. In general, our result indicates the importance of large-scale initial and lateral boundary conditions in re-producing basic features of cloudiness and its vertical structures. Based on our case study, we find overall the six-hydrometer single-moment MP scheme(WSM6) [Hong and Lim, 2006] in the WRF model si25 mulates the best agree- ment with the TWPICE observational analysis.

Wang, Yi; Long, Charles N.; Leung, Lai-Yung R.; Dudhia, Jimy; McFarlane, Sally A.; Mather, James H.; Ghan, Steven J.; Liu, Xiaodong

2009-11-05T23:59:59.000Z

194

Tropical rainforest biodiversity: field and  

E-Print Network (OSTI)

. The Udzungwas in particular, are one of the single, most important areas in Africa for biodiversity conservationTropical rainforest biodiversity: field and GIS tools for assessing, monitoring and mapping II with Tanzania National ParksTanzania National Parks andand Wildlife Conservation SocietyWildlife Conservation

195

Total lightning observations of severe convection over North Texas  

E-Print Network (OSTI)

potential. Total lightning data were obtained from Vaisala Inc.’s Dallas/Fort Worth (D/FW) Lightning Detection and Ranging (LDAR) network. Radar data from two Weather Surveillance Radar – 1988 Doppler (WSR-88D) sites were used for position data...

McKinney, Christopher Michael

2009-05-15T23:59:59.000Z

196

Three-dimensional simulations of the upper radiation–convection transition layer in subgiant stars  

Science Journals Connector (OSTI)

......University of Science Technology, Hong Kong...subgiant of one solar mass and a lower-gravity...of convection cell sizes. Differences...contrast with 2 106 cells observed on the solar surface. Observations...800 times the solar radius (Gray...approximately 600 cells would be needed......

F. J. Robinson; P. Demarque; L. H. Li; S. Sofia; Y.-C. Kim; K. L. Chan; D. B. Guenther

2004-02-01T23:59:59.000Z

197

Convective Cooling and Passive Stack Improvements in Motors (Presentation)  

SciTech Connect

This presentation discusses current research at NREL in convective cooling and passive stack improvements in motors.

Bennion, K.

2014-06-01T23:59:59.000Z

198

Heat Transport by Turbulent Rayleigh-Benard Convection  

SciTech Connect

We have developed a research program dedicated to the quantitative laboratory study of turbulent convection.

None

2008-10-03T23:59:59.000Z

199

Breakdown of large-scale circulation in turbulent rotating convection  

Science Journals Connector (OSTI)

Turbulent rotating convection in a cylinder is investigated both numerically and experimentally at Rayleigh number Ra=109 and Prandtl number ?=6.4. In this letter we discuss two topics: the breakdown under rotation of the domain-filling large-scale circulation (LSC) typical for confined convection, and the convective heat transfer through the fluid layer, expressed by the Nusselt number. The presence of the LSC is addressed for several rotation rates. For Rossby numbers Ro1.2 no LSC is found (the Rossby number indicates relative importance of buoyancy over rotation, hence small Ro indicates strong rotation). For larger Rossby numbers a precession of the LSC in anticyclonic direction (counter to the background rotation) is observed. It is shown that the heat transfer has a maximal value close to Ro=0.18 being about 15% larger than in the non-rotating case Ro=?. Since the LSC is no longer present at this Rossby value we conclude that the peak heat transfer is independent of the LSC.

R. P. J. Kunnen; H. J. H. Clercx; B. J. Geurts

2008-01-01T23:59:59.000Z

200

Steady, three-dimensional, internally heated convection  

SciTech Connect

Numerical calculations have been carried out of steady, symmetric, three-dimensional modes of convection in internally heated, infinite Prandtl number, Boussinesq fluids at a Rayleigh number of 1.4[times]10[sup 4] in a spherical shell with inner/outer radius of 0.55 and in a 3[times]3[times]1 rectangular box. Multiple patterns of convection occur in both geometries. In the Cartesian geometry the patterns are dominated by cylindrical cold downflows and a broad hot upwelling. In the spherical geometry the patterns consist of cylindrical cold downwellings centered either at the vertices of a tetrahedron or the centers of the faces of a cube. The cold downflow cylinders are immersed in a background of upwelling within which there are cylindrical hot concentrations (plumes) and hot halos around the downflows. The forced hot upflow return plumes of internally heated spherical convection are fundamentally different from the buoyancy-driven plumes of heated from below convection.

Schubert, G. (Department of Earth and Space Sciences and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, California 90024 (United States)); Glatzmaier, G.A.; Travis, B. (Earth and Environmental Sciences, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States))

1993-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical convection observed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Circulation and convection in the Irminger Sea  

E-Print Network (OSTI)

Aspects of the circulation and convection in the Irminger Sea are investigated using a variety of in-situ, satellite, and atmospheric reanalysis products. Westerly Greenland tip jet events are intense, small-scale wind ...

Våge, Kjetil

2010-01-01T23:59:59.000Z

202

Cloud Conditions Favoring Secondary Ice Particle Production in Tropical Maritime Convection  

Science Journals Connector (OSTI)

Progress in understanding the formation of ice in lower-tropospheric clouds is slowed by the difficulties in characterizing the many complex interactions that lead to ice initiation and to the dynamic, non-steady-state nature of the clouds. The ...

Andrew Heymsfield; Paul Willis

2014-12-01T23:59:59.000Z

203

A comparison of tropical mesoscale convective systems in El Nino and La Nina  

E-Print Network (OSTI)

the two years tend to follow these patterns. There was a greater number of MCSs in the Central Pacific and East Pacific in the El Nino year and fewer MCSs in the Maritime Continent. The area distributions and median intensities of MCSs were found...

Zolman, Jody Lynn

1999-01-01T23:59:59.000Z

204

The QBO's influence on lightning production and deep convection in the tropics  

E-Print Network (OSTI)

(increase) about the equator and increase (decrease) in off-equator regions. QBO modulation of tropopause height induces a higher/colder (lower/warmer) tropopause near the equator during the east (west) phase. While the expectation was that decreases...

Hernandez, Celina Anne

2009-05-15T23:59:59.000Z

205

NPP Tropical Forest: Kade, Ghana  

NLE Websites -- All DOE Office Websites (Extended Search)

Kade, Ghana, 1957-1972 Kade, Ghana, 1957-1972 [PHOTOGRAPH] Photograph: Forest after clearing of secondary growth at the Kade site (click on the photo to view a series of images from this site). Data Citation Cite this data set as follows: Nye, P. H., and D. J. Greenland. 1998. NPP Tropical Forest: Kade, Ghana, 1957-1972. Data set. Available on-line [http://www.daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. Description Biomass and nutrient content of different vegetation components and soil for a secondary tropical forest were determined in the late 1950s at the Kade Agricultural Research Station of the former University College, Ghana. Net primary production (NPP) was estimated on the basis of standing biomass accumulation and litter fall. Later studies on litter and wood fall and

206

NPP Tropical Forest: Chamela, Mexico  

NLE Websites -- All DOE Office Websites (Extended Search)

Chamela, Mexico, 1982-1995 Chamela, Mexico, 1982-1995 [PHOTOGRAPH] Photograph: Litter trap and throughfall collector in the Chamela forest (click on the photo to view a series of images from this site) Data Citation Cite this data set as follows: Maass, M., and A. Martinez-Yrizar. 2001. NPP Tropical Forest: Chamela, Mexico, 1982-1995. Data set. Available on-line [http://www.daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. Description Net primary productivity (NPP) of a tropical dry deciduous forest was estimated, based on the integration of ecosystem data obtained in various years between 1982 and 1995, at the Chamela Biological Station of the National Autonomous University of Mexico (UNAM). The Biosphere Reserve Chamela-Cuixmala, Jalisco, is situated near the

207

NPP Tropical Forest: Pasoh, Malaysia  

NLE Websites -- All DOE Office Websites (Extended Search)

Pasoh, Malaysia, 1971-1973 Pasoh, Malaysia, 1971-1973 [PHOTOGRAPH] Photograph: Profile of the Pasoh Forest (click on the photo to view a series of images from this site) Data Citation Cite this data set as follows: Kira, T., N. Manokaran, and S. Appanah. 1998. NPP Tropical Forest: Pasoh, Malaysia, 1971-1973. Data set. Available on-line [http://www.daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. Description Biomass and productivity of a lowland tropical forest in the Pasoh Forest Reserve, Malaysia, were determined from 1971 to 1973, under the auspices of the International Biological Programme. From 1970 to 1978, intensive research on lowland rain forest ecology and dynamics took place under a joint research project between the University of Malaya (UM) and the

208

Ecotoxicology of tropical marine ecosystems  

SciTech Connect

The negative effects of chemical contaminants on tropical marine ecosystems are of increasing concern as human populations expand adjacent to these communities. Watershed streams and ground water carry a variety of chemicals from agricultural, industrial, and domestic activities, while winds and currents transport pollutants from atmospheric and oceanic sources to these coastal ecosystems. The implications of the limited information available on impacts of chemical stressors on mangrove forests, seagrass meadows, and coral reefs are discussed in the context of ecosystem management and ecological risk assessment. Three classes of pollutants have received attention: heavy metals, petroleum, and synthetic organics. Heavy metals have been detected in all three ecosystems, causing physiological stress, reduced reproductive success, and outright mortality in associated invertebrates and fishes. Oil spills have been responsible for the destruction of entire coastal shallow-water communities, with recovery requiring years. Herbicides are particularly detrimental to mangroves and seagrasses and adversely affect the animal-algal symbioses in corals. Pesticides interfere with chemical cues responsible for key biological processes, including reproduction and recruitment of a variety of organisms. Information is lacking with regard to long-term recovery, indicator species, and biomarkers for tropical communities. Critical areas that are beginning to be addressed include the development of appropriate benchmarks for risk assessment, baseline monitoring criteria, and effective management strategies to protect tropical marine ecosystems in the face of mounting anthropogenic disturbance.

Peters, E.C. [Tetra Tech, Inc., Fairfax, VA (United States); Gassman, N.J.; Firman, J.C. [Univ. of Miami, FL (United States). Rosenstiel School of Marine and Atmospheric Science; Richmond, R.H. [Univ. of Guam, Mangilao (Guam). Marine Lab.; Power, E.A. [EVS Environment Consultants, Ltd., North Vancouver, British Columbia (Canada)

1997-01-01T23:59:59.000Z

209

UPDATE: Tropical Storm Isaac | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

UPDATE: Tropical Storm Isaac UPDATE: Tropical Storm Isaac UPDATE: Tropical Storm Isaac August 27, 2012 - 6:30pm Addthis Satellite image of Tropical Storm Isaac. | Courtesy of NOAA. Satellite image of Tropical Storm Isaac. | Courtesy of NOAA. April Saylor April Saylor Former Digital Outreach Strategist, Office of Public Affairs Tropical Storm Isaac has impacted Florida and is expected to make landfall along the Gulf Coast by early morning on August 29. As thousands of Gulf Coast residents are without power, the Energy Department's Office of Electricity Delivery and Energy Reliability will publish Emergency Situation Reports that provide details on customer outages and other energy sector impacts in the storm's path, as well as recovery and restoration activities being undertaken. The first Situation

210

Toward a Mesoscale Observation Network in Southeast Asia  

Science Journals Connector (OSTI)

The current weather observation network in Southeast Asia is unable to support the accurate monitoring and prediction of the region's predominantly convective weather. Establishing a multisensor mesoscale observation network comprising automated ...

Tieh-Yong Koh; Chee-Kiat Teo

2009-04-01T23:59:59.000Z

211

Tropical Cloud Life Cycle and Overlap Structure  

NLE Websites -- All DOE Office Websites (Extended Search)

Tropical Cloud Life Cycle and Overlap Structure Vogelmann, Andrew Brookhaven National Laboratory Jensen, Michael Brookhaven National Laboratory Kollias, Pavlos Brookhaven National...

212

Convection automated logic oven control  

SciTech Connect

For the past few years, there has been a greater push to bring more automation to the cooling process. There have been attempts at automated cooking using a wide range of sensors and procedures, but with limited success. The authors have the answer to the automated cooking process; this patented technology is called Convection AutoLogic (CAL). The beauty of the technology is that it requires no extra hardware for the existing oven system. They use the existing temperature probe, whether it is an RTD, thermocouple, or thermistor. This means that the manufacturer does not have to be burdened with extra costs associated with automated cooking in comparison to standard ovens. The only change to the oven is the program in the central processing unit (CPU) on the board. As for its operation, when the user places the food into the oven, he or she is required to select a category (e.g., beef, poultry, or casseroles) and then simply press the start button. The CAL program then begins its cooking program. It first looks at the ambient oven temperature to see if it is a cold, warm, or hot start. CAL stores this data and then begins to look at the food`s thermal footprint. After CAL has properly detected this thermal footprint, it can calculate the time and temperature at which the food needs to be cooked. CAL then sets up these factors for the cooking stage of the program and, when the food has finished cooking, the oven is turned off automatically. The total time for this entire process is the same as the standard cooking time the user would normally set. The CAL program can also compensate for varying line voltages and detect when the oven door is opened. With all of these varying factors being monitored, CAL can produce a perfectly cooked item with minimal user input.

Boyer, M.A.; Eke, K.I. [Apollo U.S.A. Inc., Orlando, FL (United States)] [Apollo U.S.A. Inc., Orlando, FL (United States)

1998-03-01T23:59:59.000Z

213

The Role of the Tropics in Abrupt Climate Changes  

SciTech Connect

Topics addressed include: abrupt climate changes and ocean circulation in the tropics; what controls the ocean thermal structure in the tropics; a permanent El Niño in paleoclimates; the energetics of the tropical ocean.

Fedorov, Alexey [Yale University] [Yale University

2013-12-07T23:59:59.000Z

214

Influence of Tropical Tropopause Layer Cooling on Atlantic Hurricane Activity  

E-Print Network (OSTI)

Virtually all metrics of Atlantic tropical cyclone activity show substantial increases over the past two decades. It is argued here that cooling near the tropical tropopause and the associated decrease in tropical cyclone ...

Solomon, Susan

215

Relationships between Tropical Cyclone Intensity and Eyewall Structure as Determined by Radial Profiles of Inner-Core Infrared Brightness Temperature  

Science Journals Connector (OSTI)

Radial profiles of infrared brightness temperature for 2405 different satellite observations from 14 western North Pacific tropical cyclones (TCs) from the 2012 season were analyzed and compared to intensity and changes in intensity. Four critical ...

Elizabeth R. Sanabia; Bradford S. Barrett; Caitlin M. Fine

2014-12-01T23:59:59.000Z

216

Characterization of Trapped Lignin-Degrading Microbes in Tropical...  

NLE Websites -- All DOE Office Websites (Extended Search)

Trapped Lignin-Degrading Microbes in Tropical Forest Soil. Characterization of Trapped Lignin-Degrading Microbes in Tropical Forest Soil. Abstract: Lignin is often the most...

217

Relationships between lightning and properties of convective cloud Joanna M. Futyan1,2  

E-Print Network (OSTI)

August 2007. [1] Satellite observations of convective system properties and lightning flash rate are used with the lightning flash rate. A roughly second order power-law fit to the mean radar echo top height above the 0°C isotherm is shown to capture both regional and land-ocean contrasts in lightning occurrence and flash rate

218

Using CASA IP1 to Diagnose Kinematic and Microphysical Interactions in a Convective Storm  

E-Print Network (OSTI)

bulk hydrometeor identification and dual-Doppler wind retrievals. Comparisons are made with the nearby-band radars are used to observe a convective storm. A fuzzy logic hydrometeor identification algorithm the type of echoes in the network based on storm identification al- gorithms, then allocates radars

Rutledge, Steven

219

BUBBLE CHARACTERISTICS AND CONVECTIVE EFFECTS IN THE FLOW BOILING HEAT TRANSFER OF BINARY MIXTURES  

E-Print Network (OSTI)

BUBBLE CHARACTERISTICS AND CONVECTIVE EFFECTS IN THE FLOW BOILING HEAT TRANSFER OF BINARY MIXTURES on the bubble growth and associated heat transfer phenomena. The present work focuses on obtaining the bubble. The bubble growth is observed using a high speed camera (1000 fps) under a magnification of 290X. The bubble

Kandlikar, Satish

220

Numerical study of pattern formation following a convective instability in non-Boussinesq fluids  

Science Journals Connector (OSTI)

We present a numerical study of a model of pattern formation following a convective instability in a non-Boussinesq fluid. It is shown that many of the features observed in convection experiments conducted on CO2 gas can be reproduced by using a generalized two-dimensional Swift-Hohenberg equation. The formation of hexagonal patterns, rolls, and spirals is studied, as well as the transitions and competition among them. We also study nucleation and growth of hexagonal patterns and find that the front velocity in this two-dimensional model is consistent with the prediction of marginal stability theory for one-dimensional fronts.

Hao-wen Xi; Jorge Viñals; J. D. Gunton

1992-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "tropical convection observed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Diurnal Precipitation Regimes in the Global Tropics  

Science Journals Connector (OSTI)

Diurnal variations of the global tropical precipitation are documented by using two complementary Tropical Rainfall Measuring Mission (TRMM) datasets (3B42 and 3G68) for 1998–2006 in an attempt to provide a unified view of the diurnal cycle and a ...

Kazuyoshi Kikuchi; Bin Wang

2008-06-01T23:59:59.000Z

222

Inverse natural convection problem of estimating wall heat flux using a moving sensor  

SciTech Connect

Inverse heat transfer problems have many applications in various branch of science and engineering. Here, the inverse problem of determining heat flux at the bottom wall of a two-dimensional cavity from temperature measurement in the domain is considered. The Boussinesq equation is used to model the natural convection induced by the wall heat flux. The inverse natural convection problem is posed as a minimization problem of the performance function, which is the sum of square residuals between calculated and observed temperature, by means of a conjugate gradient method. Instead of employing several fixed sensors, a single sensor is used which is moving at a given frequency over the bottom wall. The present method solves the inverse natural convection problem accurately without a priori information about the unknown function to be estimated.

Park, H.M.; Chung, O.Y.

1999-11-01T23:59:59.000Z

223

Origins of convective activity over Panama  

E-Print Network (OSTI)

Satellite-derived outgoing longwave radiation (OLR) data. were used to examine convective variability over the Panama region. Time series analysis of the area- averaged daily OLR data, for 1984 and 1985 revealed a, persistent 12-d oscillation... in convective activity during each season. Composite analyses of OLR data, for the area 120'W-40'W and 35'S-35'N for the 1984 dry (1 January ? 9 May) and wet (10 Msy? 4 December) seasons showed this oscillation extends beyond Panama and the Central America...

Strager, Christopher Stephen

1989-01-01T23:59:59.000Z

224

Triggering Deep Convection with a Probabilistic Plume Model  

Science Journals Connector (OSTI)

A model unifying the representation of the planetary boundary layer and dry, shallow, and deep convection, the probabilistic plume model (PPM), is presented. Its capacity to reproduce the triggering of deep convection over land is analyzed in ...

Fabio D’Andrea; Pierre Gentine; Alan K. Betts; Benjamin R. Lintner

2014-11-01T23:59:59.000Z

225

Heat Transfer by Free Convection in a Liquid Metal  

Science Journals Connector (OSTI)

19 December 1961 research-article Heat Transfer by Free Convection in a Liquid Metal F. J. Bayley...an experimental investigation of the free convection heat transfer process under the special conditions associated with...

1961-01-01T23:59:59.000Z

226

Structures and Dynamics of Quasi-2D Mesoscale Convective Systems  

Science Journals Connector (OSTI)

Recently, three distinct archetypes for midlatitude linear mesoscale convective systems (MCSs) have been identified. This article focuses on the fundamentals of two of these archetypes: convective lines with trailing stratiform (TS) precipitation ...

Matthew D. Parker; Richard H. Johnson

2004-03-01T23:59:59.000Z

227

Structure and evolution of a convective band MCS  

E-Print Network (OSTI)

The structure and evolution of the synoptic, mesoscale, and lightning characteristics of the 5 May 1993 non-squall line Mesoscale Convective System has been described. This storm was a long-lived Mesoscale Convective Complex. Its formation...

Valdes-Manzanilla, Arturo

2012-06-07T23:59:59.000Z

228

A Moisture-Stratiform Instability for Convectively Coupled Waves  

Science Journals Connector (OSTI)

A simple model of two vertical modes is constructed and analyzed to reveal the basic instability mechanisms of convectively coupled waves. The main novelty of this model is a convective parameterization based on the quasi-equilibrium concept and ...

Zhiming Kuang

2008-03-01T23:59:59.000Z

229

Radiative–Convective Equilibrium over a Land Surface  

Science Journals Connector (OSTI)

Radiative–convective equilibrium (RCE) describes an idealized state of the atmosphere in which the vertical temperature profile is determined by a balance between radiative and convective fluxes. While RCE has been applied extensively over oceans, ...

Nicolas Rochetin; Benjamin R. Lintner; Kirsten L. Findell; Adam H. Sobel; Pierre Gentine

2014-12-01T23:59:59.000Z

230

PHYSICAL, CHEMICAL, AND BIOLOGICAL OBSERVATIONS IN THE EASTERN TROPICAL  

E-Print Network (OSTI)

. Thomas University of California Scripps Institution of Oceanography La Jolla, California United States phosphorus 6 Nitrate, nitrite, and silicate 7 Incident solar radiation : 7 Submarine daylight 7 Chlorophyll Cali- fornia, thence across the mouth of the Gulf of California and along the coast of southern Mexico

231

Observational and numerical study of Atlantic tropical instability waves  

E-Print Network (OSTI)

regional climate model and one global climate model are applied to study the mechanism of atmospheric response to the Atlantic TIWs with daily TMI satellite SST forcing. Both models successfully simulated the wind velocity, wind convergence and pre...

Wu, Qiaoyan

2009-06-02T23:59:59.000Z

232

CONVECTION AND DIFFERENTIAL ROTATION IN F-TYPE STARS  

SciTech Connect

Differential rotation is a common feature of main-sequence spectral F-type stars. In seeking to make contact with observations and to provide a self-consistent picture of how differential rotation is achieved in the interiors of these stars, we use the three-dimensional anelastic spherical harmonic (ASH) code to simulate global-scale turbulent flows in 1.2 and 1.3 M{sub Sun} F-type stars at varying rotation rates. The simulations are carried out in spherical shells that encompass most of the convection zone and a portion of the stably stratified radiative zone below it, allowing us to explore the effects of overshooting convection. We examine the scaling of the mean flows and thermal state with rotation rate and mass and link these scalings to fundamental parameters of the simulations. Indeed, we find that the differential rotation becomes much stronger with more rapid rotation and larger mass, scaling as {Delta}{Omega}{proportional_to}M {sup 3.9}{Omega}{sup 0.6}{sub 0}. Accompanying the growing differential rotation is a significant latitudinal temperature contrast, with amplitudes of 1000 K or higher in the most rapidly rotating cases. This contrast in turn scales with mass and rotation rate as {Delta}T{proportional_to}M {sup 6.4}{Omega}{sup 1.6}{sub 0}. On the other hand, the meridional circulations become much weaker with more rapid rotation and with higher mass, with their kinetic energy decreasing as KE{sub MC}{proportional_to}M {sup -1.2}{Omega}{sup -0.8}{sub 0}. Additionally, three of our simulations exhibit a global-scale shear instability within their stable regions that persists for the duration of the simulations. The flow structures associated with the instabilities have a direct coupling to and impact on the flows within the convection zone.

Augustson, Kyle C.; Toomre, Juri [JILA and Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309 (United States); Brown, Benjamin P. [Department of Astronomy and Center for Magnetic Self-Organization (CMSO) in Laboratory and Astrophysical Plasmas, University of Wisconsin, Madison, WI 53706-1582 (United States); Brun, Allan Sacha [DSM/IRFU/SAp, CEA-Saclay and UMR AIM, CEA-CNRS-Universite Paris 7, F-91191 Gif-sur-Yvette (France); Miesch, Mark S., E-mail: Kyle.Augustson@colorado.edu [High Altitude Observatory, Center Green 1, Boulder, CO 80301 (United States)

2012-09-10T23:59:59.000Z

233

The Convective Instability Pathway to Warm Season Drought in Texas. Part II: Free-Tropospheric Modulation of Convective Inhibition  

Science Journals Connector (OSTI)

This study is concerned with the modulation by convective instability of summertime precipitation in Texas as a mechanism for maintaining or enhancing drought. The important role of convective inhibition (CIN), its dependence on the temperature ...

Boksoon Myoung; John W. Nielsen-Gammon

2010-09-01T23:59:59.000Z

234

Turbulent convection in liquid metal with and without rotation  

E-Print Network (OSTI)

is the efficiency of convective heat transfer (Nu). In general, we find that the convective behavior of liquid metal=ðkT�, where q is total heat flux and k is the fluid's thermal conductivity. Heat flux q is total heat power P by turbulent, rotating convection in liquid metal. Liquid metals are peculiar in that they diffuse heat more

235

Realistic Solar Surface Convection Simulations Robert F. Stein  

E-Print Network (OSTI)

Realistic Solar Surface Convection Simulations Robert F. Stein Michigan State University, East free simulations with re­ alistic physics of convection near the solar surface. We summarize solar convection is non­local. It is driven from a thin surface thermal boundary layer where radiative

Stein, Robert

236

Testing turbulent convection theory in solar models – I. Structure of the solar convection zone  

Science Journals Connector (OSTI)

......outer envelope of the Sun, low-temperature opacities from Alexander...SSM. Fig. 9 shows the distribution of the temperature gradient in the solar...on the structure of the Sun, especially the temperature gradient in the convection......

Y. Li; J. Y. Yang

2007-02-11T23:59:59.000Z

237

Solar MagnetoConvection David J. Bercik  

E-Print Network (OSTI)

Solar Magneto­Convection David J. Bercik Dept. of Physics and Astronomy, Michigan State University, Michigan State University, East Lansing, MI 48824, U.S.A. š Ake Nordlund Theoretical Astrophysics Center, �ster Voldgade 3, 1350 Copenhagen K, Denmark Robert F. Stein Dept. of Physics and Astronomy, Michigan

Stein, Robert

238

Laminar boundary layers in convective heat transport  

E-Print Network (OSTI)

We study Rayleigh-Benard convection in the high-Rayleigh-number and high-Prandtl-number regime, i.e., we consider a fluid in a container that is exposed to strong heating of the bottom and cooling of the top plate in the absence of inertia effects. While the dynamics in the bulk are characterized by a chaotic convective heat flow, the boundary layers at the horizontal container plates are essentially conducting and thus the fluid is motionless. Consequently, the average temperature exhibits a linear profile in the boundary layers. In this article, we rigorously investigate the average temperature and oscillations in the boundary layer via local bounds on the temperature field. Moreover, we deduce that the temperature profile is indeed essentially linear close to the horizontal container plates. Our results are uniform in the system parameters (e.g. the Rayleigh number) up to logarithmic correction terms. An important tool in our analysis is a new Hardy-type estimate for the convecting velocity field, which can be used to control the fluid motion in the layer. The bounds on the temperature field are derived with the help of local maximal regularity estimates for convection-diffusion equations.

Christian Seis

2012-12-12T23:59:59.000Z

239

Mantle Convection with Strong Subduction Zones  

E-Print Network (OSTI)

of the oceanic lithosphere within a small region of a nite element grid. By imposing velocity boundary conditions thermal structure. To make the model dynamically consistent, we specify a rate for subduction that balances the energy budget for convection, which includes an expression for the energy needed to bend

Conrad, Clint

240

EFFECTS OF ASYMMETRIC FLOWS IN SOLAR CONVECTION ON OSCILLATION MODES  

SciTech Connect

Many helioseismic measurements suffer from substantial systematic errors. A particularly frustrating one is that time-distance measurements suffer from a large center to limb effect which looks very similar to the finite light travel time, except that the magnitude depends on the observable used and can have the opposite sign. This has frustrated attempts to determine the deep meridional flow in the solar convection zone, with Zhao et al. applying an ad hoc correction with little physical basis to correct the data. In this Letter, we propose that part of this effect can be explained by the highly asymmetrical nature of the solar granulation which results in what appears to the oscillation modes as a net radial flow, thereby imparting a phase shift on the modes as a function of observing height and thus heliocentric angle.

Baldner, Charles S.; Schou, Jesper, E-mail: baldner@stanford.edu [W.W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305-4085 (United States)

2012-11-20T23:59:59.000Z

Note: This page contains sample records for the topic "tropical convection observed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Non-Boussinesq rolls in 2d thermal convection  

Science Journals Connector (OSTI)

Abstract A study of convection in a circular two dimensional cell is presented. The system is heated and cooled at two diametrically opposed points on the edge of the circle, which are parallel or anti-parallel to gravity. The latter’s role in the plane of the cell can be changed by tilting the cell. When the system is in a horizontal position, a non-trivial analytic solution for the temperature distribution of the quiescent fluid can be found. For a slight inclination, the projection of gravity in the plane of the cell is used as a perturbation parameter in the full hydrodynamic description, as the Boussinesq approximation is unjustified. To first order, the equations are solved for the stationary case and four symmetrical rolls become apparent, showing that a purely conductive state is impossible if gravity–however small–is present; an approximate closed analytical expression is obtained, which describes the four convection rolls. Further analysis is done by a direct numerical integration. Comparison with preliminary observations is mentioned.

C. Málaga; F. Mandujano; R. Peralta-Fabi; C. Arzate

2015-01-01T23:59:59.000Z

242

Experimental study of free and mixed convective flow of air in a heated cavity  

SciTech Connect

Free and mixed convection in a strongly-heated rectangular open cavity have been investigated experimentally, to observe the effects of cavity shape and inclination, and of ambient wind, on the velocity and temperature distribution were observed. The long edges of the cavity were horizontal, and parallel to an axis around which the cavity could be rotated. The aperture plane was either vertical (..cap alpha.. = 0/sup 0/), or inclined downward at ..cap alpha.. - 20/sup 0/ or ..cap alpha.. = 45/sup 0/. The height of the aperture, b, was always 0.0947 m, while the depth of the cavity, a, was set so that a/b = 0.5, 1.0, or 1.46. The bottom and back walls were electrically heated - the top wall was indirectly heated by conduction, radiation and convection. The average wall temperature and the ambient temperature were used to define the dimensionless overheat and Grashof numbers. The Prandtl number was that of air. In the studies of mixed convection, the axis of rotation was horizontal and normal to the ambient wind. The Reynolds number was varied from Re = 120 - 1100 to Re = 2000 - 8740. For both free and mixed convection, wall and gas temperature were measured with thermocouples, and shadowgraph pictures were taken. For pure free convection, three time-averaged velocity components, the corresponding normal Reynolds stress components, and one off-diagonal Reynolds stress component were measured with a two-color laser-Doppler velocimeter. A PDP-11/34 minicomputer controlled the sequence of automatic data acquisition, the statistical data reduction and its storage. Statistical results are presented numerically and graphically for two averaging procedures. The principal quantitative result for free convection is that the rate of convective heat loss across the cavity aperture plane is reduced both by increasing a/b and by increasing ..cap alpha... Qualitative observations are recorded and discussed. The most striking observation was the appearance of a periodic oscillation of frequency 2 to 5.5 Hz.

Humphrey, J.A.C.; Sherman, F.S.

1985-04-01T23:59:59.000Z

243

Convective equilibrium and mixing-length theory for stellarator reactors  

SciTech Connect

In high ..beta.. stellarator and tokamak reactors, the plasma pressure gradient in some regions of the plasma may exceed the critical pressure gradient set by ballooning instabilities. In these regions, convective cells break out to enhance the transport. As a result, the pressure gradient can rise only slightly above the critical gradient and the plasma is in another state of equilibrium - ''convective equilibrium'' - in these regions. Although the convective transport cannot be calculated precisely, it is shown that the density and temperature profiles in the convective region can still be estimated. A simple mixing-length theory, similar to that used for convection in stellar interiors, is introduced in this paper to provide a qualitative description of the convective cells and to show that the convective transport is highly efficient. A numerical example for obtaining the density and temperature profiles in a stellarator reactor is given.

Ho, D.D.M.; Kulsrud, R.M.

1985-09-01T23:59:59.000Z

244

Biological sources and sinks of methane in tropical habitats and tropical atmospheric chemistry. Doctoral thesis  

SciTech Connect

The contents of this study include: two methods for measuring methane emission from a tropical lake; methane emission by bubbling from Gatun Lake, Panama; methane emission from wetlands in central Panama; consumption of atmospheric methane in soils of central Panama: effects of agricultural development; a seasonal study of soil-atmosphere methane, carbon dioxide, and 222Rn flux in a tropical moist forest; and the effects of tropical deforestation on global and regional atmospheric chemistry.

Keller, M.M.

1990-01-01T23:59:59.000Z

245

The Phenix ultimate natural convection test  

SciTech Connect

The French sodium cooled fast reactor Phenix was shut down in 2009 after 35 years of operation. Before decommissioning, a final set of tests were performed by the CEA during 9 months. Several topics were involved such as thermal hydraulics, core physics and fuel behaviour. Among these ultimate experiments, two thermal hydraulic tests were performed: an asymmetrical test consisting in a trip of one secondary pump and a natural convection test in the primary circuit. Recognizing the unique opportunity offered by these Phenix ultimate tests, IAEA decided in 2007 to launch a Coordinated Research Project (CRP) devoted to benchmarking analyses with system codes on the Phenix natural convection test. One objective of the natural convection test in Phenix reactor is the assessment of the CATHARE system code for safety studies on future and advanced sodium cooled fast reactors. The aim of this paper is to describe this test, which was performed on June 22-23, 2009, and the associated benchmark specifications for the CRP work. The paper reminds briefly the Phenix reactor with the main physical parameters and the instrumentation used during the natural convection test. After that, the test scenario is described: - initial state at a power of 120 MWth, - test beginning resulting from a manual dry out of the two steam generators, - manual scram, - manual trip on the three primary pumps without back-up by pony motors, - setting and development of natural convection in the primary circuit, in a first phase without significant heat sink in the secondary circuits and in a second phase with significant heat sink in the secondary circuits, by opening the casing of steam generators to create an efficient heat sink, by air natural circulation in the steam generators casing. The benchmark case ends after this second phase, which corresponds to the experimental test duration of nearly 7 hours. The paper presents also the benchmark specifications data supplied by the CEA to all participants of this CRP in order to perform calculations (core, primary circuit, primary pumps, IHX, shutdown system, operating parameters, test scenario and real test conditions). Finally, main test results and analyses are presented including the evolution of the core and of the heat exchangers inlet and outlet temperatures, and some local temperature measurements. The natural convection has been easily set up in the pool type reactor Phenix with different boundary conditions at the secondary side, with or without heat sink. The data obtained during this unique test represent some very useful and precious results for the development of SFR in a wide range of thematic such as numerical methods dedicated to thermal-hydraulics safety analyses (system codes, CFD codes and coupling system and CFD codes) and instrumentation. (authors)

Gauthe, P. [CEA, DER, SESI, F-13108, Saint Paul lez Durance (France); Pialla, D.; Tenchine, D. [CEA, DEN, STMF, F-38054, Grenoble (France); Vasile, A. [CEA, DER, SESI, F-13108, Saint Paul lez Durance (France); Rochwerger, D. [CEA, DEN, DEIM, F-30207, Bagnols-sur-Ceze (France)

2012-07-01T23:59:59.000Z

246

E-Print Network 3.0 - atlantic tropical cyclones Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

between Atlantic tropical cyclone power... dif- ferent inferences about late-twenty-first-century Atlantic tropical cyclone activity9 , ranging... Atlantic tropical ... Source:...

247

Tropical Forest Foundation | Open Energy Information  

Open Energy Info (EERE)

Tropical Forest Foundation Tropical Forest Foundation Jump to: navigation, search Logo: Tropical Forest Foundation Name Tropical Forest Foundation Address 2121 Eisenhower Ave. Suite 200 Place Alexandria, Virginia Zip 22314 Region Northeast - NY NJ CT PA Area Phone number 703.518.8834 Website http://tropicalforestfoundatio Coordinates 38.8013734°, -77.0668734° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":38.8013734,"lon":-77.0668734,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

248

Nasa's Tropical Cloud Systems and Processes Experiment  

Science Journals Connector (OSTI)

In July 2005, the National Aeronautics and Space Administration investigated tropical cyclogenesis, hurricane structure, and intensity change in the eastern North Pacific and western Atlantic using its ER-2 high-altitude research aircraft. The ...

J. Halverson; M. Black; R. Rogers; S. Braun; G. Heymsfield; D. Cecil; M. Goodman; R. Hood; A. Heymsfield; T. Krishnamurti; G. McFarquhar; M. J. Mahoney; J. Molinari; J. Turk; C. Velden; D-L. Zhang; E. Zipser; R. Kakar

2007-06-01T23:59:59.000Z

249

Tropical Transition of the 2001 Australian Duck  

Science Journals Connector (OSTI)

In March 2001, a hybrid low pressure system, unofficially referred to as Donald (or the Duck), developed in the Tasman Sea under tropical–extratropical influence, making landfall on the southeastern Australian coast. Here, it is shown that ...

Luke Andrew Garde; Alexandre Bernardes Pezza; John Arthur Tristram Bye

2010-06-01T23:59:59.000Z

250

Thermocapillary convection induced by laser surface heating  

SciTech Connect

Thermocapillary convection was excited by a laser source in experiments on molten paraffin. The parameters of the resultant flow were determined. The nature of the flow was demonstrated to correspond to shear-driven boundary-layer flow at high Reynolds numbers. Correlation dependences of the flow velocity of the melt and its temperature in the surface region were derived theoretically and were shown to agree with the experimental results. When the size of the laser spot was much less than the characteristic convection scales, three regions of flow of the melt could be distinguished: a viscous surface boundary layer, a stagnation zone under the laser spot, and a large-scale region of flow with a homogeneous temperature distribution. (interaction of laser radiation with matter. laser plasma)

Gladush, G G; Drobyazko, S V; Likhanskii, V V; Loboiko, A I; Senatorov, Yu M [State Research Center of Russian Federation 'Troitsk Institute for Innovation and Fusion Research', Troitsk, Moscow Region (Russian Federation)

1998-05-31T23:59:59.000Z

251

On the connection between continental-scale land surface processes and the tropical climate in a coupled ocean-atmosphere-land system  

SciTech Connect

The impact of global tropical climate to perturbations in land surface processes (LSP) are evaluated using perturbations given by different LSP representations of continental-scale in a global climate model that includes atmosphere-ocean interactions. One representation is a simple land scheme, which specifies climatological albedos and soil moisture availability. The other representation is the more comprehensive Simplified Simple Biosphere Model, which allows for interactive soil moisture and vegetation biophysical processes. The results demonstrate that LSP processes such as interactive soil moisture and vegetation biophysical processes have strong impacts on the seasonal mean states and seasonal cycles of global precipitation, clouds, and surface air temperature. The impact is especially significant over the tropical Pacific. To explore the mechanisms for such impact, different LSP representations are confined to selected continental-scale regions where strong interactions of climate-vegetation biophysical processes are present. We find that the largest impact is mainly from LSP perturbations over the tropical African continent. The impact is through anomalous convective heating in tropical Africa due to changes in the surface heat fluxes, which in turn affect basinwide teleconnections in the Pacific through equatorial wave dynamics. The modifications in the equatorial Pacific climate are further enhanced by strong air-sea coupling between surface wind stress and upwelling, as well as effect of ocean memory. Our results further suggest that correct representations of land surface processes, land use change and the associated changes in the deep convection over tropical Africa are crucial to reducing the uncertainty when performing future climate projections under different climate change scenarios.

Ma, Hsi-Yen; Mechoso, C. R.; Xue, Yongkang; Xiao, Heng; Neelin, David; Ji, Xuan

2013-11-15T23:59:59.000Z

252

Water Vapor Budget in a Developing Tropical Cyclone and Its Implication for Tropical Cyclone Formation  

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Evolution of the water vapor budget from the tropical wave stage to the tropical cyclone stage is examined using a high-resolution numerical model simulation. The focus is on a time window from 27 h prior to genesis to 9 h after genesis, and the ...

Cody Fritz; Zhuo Wang

2014-11-01T23:59:59.000Z

253

The influence of winter convection on primary production: a parameterisation using a hydrostatic three-dimensional biogeochemical model  

E-Print Network (OSTI)

In the recent past observational and modelling studies have shown that the vertical displacement of water parcels, and therefore, phytoplankton particles in regions of deep-reaching convection plays a key role in late winter/early spring primary production. The underlying mechanism describes how convection cells capture living phytoplankton cells and recurrently expose them to sunlight. This study presents a parameterisation called `phytoconvection' which focuses on the influence of convection on primary production. This parameterisation was implemented into a three-dimensional physical-biogeochemical model and applied to the Northwestern European Continental Shelf and areas of the adjacent Northeast Atlantic. The simulation was compared to a `conventional' parameterisation with respect to its influence on phytoplankton concentrations during the annual cycle and its effect on the carbon cycle. The simulation using the new parameterisation showed good agreement with observation data recorded during winter, whe...

Große, Fabian; Pätsch, Johannes; Backhaus, Jan O

2014-01-01T23:59:59.000Z

254

Tropical cyclone genesis efficiency: mid-level versus bottom vortex Xuyang Ge and Tim Li  

E-Print Network (OSTI)

;4 1. Introduction Tropical cyclone (TC) genesis is the least understood phase in a TC life cycle is cyclogenesis in an environment with a mid-level vortex (EMV). An analysis of the WNP TC genesis in 2000 the QuikSCAT-derived surface wind observations, there was no sign

Li, Tim

255

ARM - Field Campaign - Midlatitude Continental Convective Clouds Experiment  

NLE Websites -- All DOE Office Websites (Extended Search)

Experiment (MC3E) Experiment (MC3E) Campaign Links Science Plan MC3E Website Related Campaigns Midlatitude Continental Convective Clouds Experiment: 2DVD Support 2011.04.22, Schwaller, SGP Midlatitude Continental Convective Clouds Experiment (MC3E): Airborne Instruments 2011.04.22, Poellot, AAF Midlatitude Continental Convective Clouds Experiment (MC3E): Multi-Frequency Profilers 2011.04.22, Williams, SGP Midlatitude Continental Convective Clouds Experiment: Parsivel Disdrometer Support 2011.04.22, Schwaller, SGP Midlatitude Continental Convective Clouds Experiment (MC3E): Inner Domain Thermodynamic Profiling during MC3E 2011.04.22, Turner, SGP Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Midlatitude Continental Convective Clouds Experiment (MC3E)

256

Meridional Circulation in Solar and Stellar Convection Zones  

E-Print Network (OSTI)

We present a series of 3-D nonlinear simulations of solar-like convection, carried out using the Anelastic Spherical Harmonic (ASH) code, that are designed to isolate those processes that drive and shape meridional circulations within stellar convection zones. These simulations have been constructed so as to span the transition between solar-like differential rotation (fast equator/slow poles) and ``anti-solar' differential rotation (slow equator/fast poles). Solar-like states of differential rotation, arising when convection is rotationally constrained, are characterized by a very different convective Reynolds stress than anti-solar regimes, wherein convection only weakly senses the Coriolis force. We find that the angular momentum transport by convective Reynolds stress plays a central role in establishing the meridional flow profiles in these simulations. We find that the transition from single-celled to multi-celled meridional circulation profiles in strong and weak regimes of rotational constraint is lin...

Featherstone, Nicholas A

2015-01-01T23:59:59.000Z

257

Interactions of tropical synoptic-scale features as viewed from satellite  

E-Print Network (OSTI)

University Chair of Advisory Committee: Dr. James P. McGuirk Tropical synoptic features ? a hypothesized periodic 12 d oscillation over Central America and a 2800 km eastward propagating wave over the eastern Pacific ? are examined in OLR and TOVS... satellite observations. Their interactions with each other, with tropical plumes and intraseasonal oscil- lations are found to be weak. Time series analysis of the area-averaged (140 -40 W and 35'N-35 S) daily OLR for 1984 revealed a persistent 12 d...

Winton, Susan Elizabeth

1991-01-01T23:59:59.000Z

258

Tracer Gas Transport under Mixed Convection Conditions in an Experimental  

NLE Websites -- All DOE Office Websites (Extended Search)

Tracer Gas Transport under Mixed Convection Conditions in an Experimental Tracer Gas Transport under Mixed Convection Conditions in an Experimental Atrium: Comparison Between Experiments and CFD Predictions Title Tracer Gas Transport under Mixed Convection Conditions in an Experimental Atrium: Comparison Between Experiments and CFD Predictions Publication Type Journal Article Year of Publication 2006 Authors Jayaraman, Buvaneswari, Elizabeth U. Finlayson, Michael D. Sohn, Tracy L. Thatcher, Phillip N. Price, Emily E. Wood, Richard G. Sextro, and Ashok J. Gadgil Journal Atmospheric Environment Volume 40 Start Page Chapter Pagination 5236-5250 Keywords airflow and pollutant transport group, atria, indoor airflow and pollutant transport, indoor environment department, indoor pollutant dispersion, mixed convection, turbulence model

259

Posters Mesoscale Simulations of Convective Systems with Data...  

NLE Websites -- All DOE Office Websites (Extended Search)

7 Posters Mesoscale Simulations of Convective Systems with Data Assimilation During June 1993 in the Southern Great Plains J. Dudhia Mesoscale and Microscale Meteorology Division...

260

Diurnal Cycle of Convection at the ARM SGP Site: Role of Large-Scale Forcing, Surface Fluxes, and Convective Inhibition  

NLE Websites -- All DOE Office Websites (Extended Search)

Diurnal Cycle of Convection at the ARM SGP Site: Diurnal Cycle of Convection at the ARM SGP Site: Role of Large-Scale Forcing, Surface Fluxes, and Convective Inhibition G. J. Zhang Center for Atmospheric Sciences Scripps Institution of Oceanography La Jolla, California Introduction Atmospheric convection undergoes strong diurnal variation over both land and oceans (Gray and Jacobson 1977; Dai 2001; Nesbitt and Zipser 2003). Because of the nature of the diurnal variation of solar radiation, the phasing of convection with solar radiation has a significant impact on the atmospheric radiation budget and cloud radiative forcing. A number of studies have investigated the possible mechanisms of the diurnal variation of convection (Gray and Jacobson 1977; Randall et al. 1991; Dai et al. 1999; Dai 2001). Yet, in regional and global climate models, the diurnal variation of

Note: This page contains sample records for the topic "tropical convection observed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Local origins of interdecadal Pacific variability in the tropical and North Pacific Ocean: evidence from a comparative study of coral oxygen isotope records  

Science Journals Connector (OSTI)

Interdecadal Pacific variability (IPV) is commonly observed in both the tropical and mid-latitude Pacific Ocean, and has a widespread influence on surface climate in the Pan-Pacific Basin. This variability is rec...

Wenfeng Deng; Gangjian Wei

2014-08-01T23:59:59.000Z

262

Global Identification of Previously Undetected Pre-Satellite-Era Tropical Cyclone Candidates in NOAA/CIRES Twentieth-Century Reanalysis Data  

Science Journals Connector (OSTI)

Prior to the satellite era, limited synoptic observation networks led to an indefinite number of tropical cyclones (TCs) remaining undetected. This period of decreased confidence in the TC climatological record includes the first two-thirds of the ...

Ryan E. Truchelut; Robert E. Hart; Briana Luthman

2013-10-01T23:59:59.000Z

263

Antisymmetric polar modes of thermal convection in rotating fluid spherical shells at high Taylor numbers  

E-Print Network (OSTI)

of the liquid sodium ( = 0.01). For the first time, it is shown that at very high Taylor numbers the first numbers: 47.15.-x, 47.20.-k Electronic address: sanchez@fa.upc.edu Electronic address: marta@fa.upc by the properties of convection. The large-scale zonal winds observed in the surface of Jupiter at mid- and low

Sánchez, Juan

264

Probabilistic Multiple-Linear Regression Modeling for Tropical Cyclone Intensity  

Science Journals Connector (OSTI)

The authors describe the development and verification of a statistical model relating tropical cyclone intensity to the local large-scale environment. A multiple linear regression framework is used to estimate the expected intensity of a tropical ...

Chia-Ying Lee; Michael K. Tippett; Suzana J. Camargo; Adam H. Sobel

265

A Parameter for Forecasting Tornadoes Associated with Landfalling Tropical Cyclones  

Science Journals Connector (OSTI)

The authors develop a statistical guidance product, the tropical cyclone tornado parameter (TCTP), for forecasting the probability of one or more tornadoes during a 6-h period that are associated with landfalling tropical cyclones affecting the ...

Matthew J. Onderlinde; Henry E. Fuelberg

2014-10-01T23:59:59.000Z

266

Diurnal variation of tropical precipitation using five years TRMM data  

E-Print Network (OSTI)

The tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) and Precipitation Radar (PR) data are used in this study to reveal diurnal variations of precipitation over the Tropics (30?S ? 30?N) from January, 1998...

Wu, Qiaoyan

2004-11-15T23:59:59.000Z

267

Annual Adjustment of the Thermocline in the Tropical Pacific Ocean  

Science Journals Connector (OSTI)

In this paper the amplitude-phase characteristics of the annual adjustment of the thermocline in the entire tropical Pacific Ocean are described and numerical experiments with a tropical ocean model are performed to assess the roles of the major ...

Bin Wang; Renguang Wu; Roger Lukas

2000-02-01T23:59:59.000Z

268

Transitions between patterns in thermal convection  

SciTech Connect

We present experimental studies of the transitions between conduction, hexagons, and rolls in non-Boussinesq convection of gaseous CO{sub 2} in a cylindrical cell of radius-to-height ratio 86. Except for the transition from conduction to hexagons, transitions occur when the two states involved have nearly the same value of a generalized potential rather than at the stability limits. Conduction gives way to hexagons via the propagation of a front connecting the two states, while the transitions between hexagons and rolls are facilitated at the cell walls which appear to nucleate the minority state.

Bodenschatz, E.; de Bruyn, J.R.; Ahlers, G.; Cannell, D.S. (Department of Physics and Center for Nonlinear Science, University of California, Santa Barbara, Santa Barbara, California (USA) Memorial University of Newfoundland, St. John's, Newfoundland (Canada))

1991-11-25T23:59:59.000Z

269

NPP Tropical Forest: Luquillo, Puerto Rico  

NLE Websites -- All DOE Office Websites (Extended Search)

Luquillo, Puerto Rico, 1963-1994 Luquillo, Puerto Rico, 1963-1994 Data Citation Cite this data set as follows: Lugo, A. E., F. Scatena, and C. F. Jordan. 1999. NPP Tropical Forest: Luquillo, Puerto Rico, 1963-1994. Data set. Available on-line [http://www.daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. Description Productivity of lower montane tropical forest has been determined at various study sites within the Luquillo Experimental Forest from 1963 to the present. The Luquillo Experimental Forest is situated in the Luquillo Mountains of eastern Puerto Rico (18.32 N 65.82 W), about 35 km east-southeast of San Juan, and operates under the auspices of the International Institute of Tropical Forestry, Rio Pedras, Puerto Rico. Its total area is about 11,000

270

Tropical Forest Trust | Open Energy Information  

Open Energy Info (EERE)

Tropical Forest Trust Tropical Forest Trust Name Tropical Forest Trust Address The Forest Trust 721 NW Ninth Avenue, Suite 195 Place Portland, Oregon Zip 97209 Region Pacific Northwest Area Year founded 1999 Website http://www.tft-forests.org/ Coordinates 45.5284073°, -122.6803494° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":45.5284073,"lon":-122.6803494,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

271

Tropical Africa: Total Forest Biomass (By Country)  

NLE Websites -- All DOE Office Websites (Extended Search)

Tropical Africa: Total Forest Biomass (By Country) Tropical Africa: Total Forest Biomass (By Country) image Brown, S., and G. Gaston. 1996. Tropical Africa: Land Use, Biomass, and Carbon Estimates For 1980. ORNL/CDIAC-92, NDP-055. Carbon Dioxide Information Analysis Center, U.S. Department of Energy, Oak Ridge National Laboratory, Oak Ridge, Tennessee, U.S.A. More Maps Calculated Actual Aboveground Live Biomass in Forests (1980) Maximum Potential Biomass Density Land Use (1980) Area of Closed Forests (By Country) Mean Biomass of Closed Forests (By County) Area of Open Forests (By Country) Mean Biomass of Open Forests (By County) Percent Forest Cover (By Country) Population Density - 1990 (By Administrative Unit) Population Density - 1980 (By Administrative Unit) Population Density - 1970 (By Administrative Unit)

272

WMO/CAS/WWW SEVENTH INTERNATIONAL WORKSHOP ON TROPICAL CYCLONES  

E-Print Network (OSTI)

. As outlined by Dunkerton et al. (2009, hereafter DMW09), the problem of tropical cyclogenesis in the real

Smith, Roger K.

273

The Impact of Tropical Storm Paul (1999) on the Motion and Rainfall Associated with Tropical Storm Rachel (1999) near Taiwan  

Science Journals Connector (OSTI)

A heavy rainfall event associated with the passage of Tropical Storm Rachel (1999) over southern Taiwan was studied in which a conceptual model was proposed. In the model, Tropical Storm Paul (1999) plays an important role in impeding the ...

Chun-Chieh Wu; Kevin K. W. Cheung; Jan-Huey Chen; Cheng-Chuan Chang

2010-05-01T23:59:59.000Z

274

Predicting free laminar convection heat transfer on curvilinear surfaces  

SciTech Connect

Free laminar convection on an isothermal surface of cylindrical and axisymmetric bodies of arbitrary cross section is considered in the Boussinesq approximation. The problem is solved by the method of generalized similarity in its local approximation. Universal formulae are obtained for calculating the local Nusselt number. Prediction of convection on a heated horizontal cylindrical and sphere are given as examples of the method.

Stepanyants, L.G.; Shelukho, S.I.

1989-07-01T23:59:59.000Z

275

EXPERIMENTAL INVESTIGATION OF BOILING HEAT CONVECTION IN A FRACTURE  

E-Print Network (OSTI)

EXPERIMENTAL INVESTIGATION OF BOILING HEAT CONVECTION IN A FRACTURE A REPORT SUBMITTED between heat conduction and heat convection with boiling flow in a rock fracture. An experimental coefficient. This coefficient is the proportionality factor between the heat flux to a fracture surface

Stanford University

276

Environmental Distinctions between Cellular and Slabular Convective Lines  

Science Journals Connector (OSTI)

The organizational mode of quasi-linear convective systems often falls within a spectrum of modes described by a line of discrete cells on one end (“cellular”) and an unbroken two-dimensional swath of ascent on the other (“slabular”). Convective ...

Richard P. James; J. Michael Fritsch; Paul M. Markowski

2005-09-01T23:59:59.000Z

277

Deep storage of oceanic crust in a vigorously convecting mantle  

E-Print Network (OSTI)

Deep storage of oceanic crust in a vigorously convecting mantle J. P. Brandenburg1 and P. E. van: Brandenburg, J. P., and P. E. van Keken (2007), Deep storage of oceanic crust in a vigorously convecting cycle of creation, interaction with seawater and subduction may be responsi- ble for the loss of Pb

van Keken, Peter

278

Theoretical analysis of convective heat transfer enhancement of microencapsulated phase change material slurries  

Science Journals Connector (OSTI)

...This paper analyzes the convective heat transfer enhancement mechanism of microencapsulated phase change material slurries based on the analogy between convective ... addition, the conventional Nusselt number ...

Yinping Zhang; Xianxu Hu; Xin Wang

2003-12-01T23:59:59.000Z

279

BNL | Midlatitude Continental Convective Clouds Experiment (MC3E)  

NLE Websites -- All DOE Office Websites (Extended Search)

Midlatitude Continental Convective Clouds Experiment Midlatitude Continental Convective Clouds Experiment Convective processes play a critical role in the Earth's energy balance through the redistribution of heat and moisture in the atmosphere and their link to the hydrological cycle. Accurate representation of convective processes in numerical models is vital towards improving current and future simulations of Earths climate system. Despite improvements in computing power, current operational weather and global climate models are unable to resolve the natural temporal and spatial scales important to convective processes and therefore must turn to parameterization schemes to represent these processes. In turn, parameterization schemes in cloud-resolving models need to be evaluated for their generality and application to a

280

Alien plant invasions in tropical and sub-tropical savannas: patterns, processes and prospects  

E-Print Network (OSTI)

Tanzania Species Family Alien plant invasions in savannasLo pez-Olmedo et al. 2007). Alien plant invasions in Africanspecies of naturalised alien plants for tropical savannas in

Foxcroft, Llewellyn C.; Richardson, David M.; Rejmánek, Marcel; Pyšek, Petr

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical convection observed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Simulation of Rayleigh-Benard convection using a lattice Boltzmann method  

SciTech Connect

Rayleigh-Benard convection is numerically simulated in two and three dimensions using a recently developed two-component lattice Boltzmann equation (LBE) method. The density field of the second component, which evolves according to the advection-diffusion equation of a passive scalar, is used to simulate the temperature field. A body force proportional to the temperature is applied, and the system satisfies the Boussinesq equation except for a slight compressibility. A no-slip, isothermal boundary condition is imposed in the vertical direction, and periodic boundary conditions are used in horizontal directions. The critical Rayleigh number for the onset of the Rayleigh-Benard convection agrees with the theoretical prediction. As the Rayleigh number is increased higher, the steady two-dimensional convection rolls become unstable. The wavy instability and aperiodic motion observed, as well as the Nusselt number as a function of the Rayleigh number, are in good agreement with experimental observations and theoretical predictions. The LBE model is found to be efficient, accurate, and numerically stable for the simulation of fluid flows with heat and mass transfer. {copyright} {ital 1997} {ital The American Physical Society}

Shan, X. [U.S. Air Force Phillips Laboratory, Hanscom Air Force Base, Massachusetts 01731 (United States)] [U.S. Air Force Phillips Laboratory, Hanscom Air Force Base, Massachusetts 01731 (United States); [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

1997-03-01T23:59:59.000Z

282

Large plasma pressure perturbations and radial convective transport in a tokamak  

SciTech Connect

Strongly localized plasma structures with large pressure inhomogeneities (such as plasma blobs in the scrape-off-layer (SOL)/shadow regions, pellet clouds, ELMs) observed in the tokamaks, stellarators and linear plasma devices. Experimental studies of these phenomena reveal striking similarities including more convective rather than diffusive radial plasma transport. We suggest that rather simple models can describe many essentials of blobs, ELMs, and pellet clouds dynamics. The main ingredient of these models is the effective plasma gravity caused by magnetic curvature, centrifugal or friction forces effects. As a result, the equations governing plasma transport in such localized structures appear to be rather similar to that used to describe nonlinear evolution of thermal convection in the Boussinesq approximation (directly related to the Rayleigh-Taylor instability).

Krasheninnikov, S; Ryutov, D; Yu, G

2004-02-04T23:59:59.000Z

283

Meridional circulation dynamics from 3D MHD global simulations of solar convection  

E-Print Network (OSTI)

The form of the solar meridional circulation is a very important ingredient for mean field flux transport dynamo models. Yet a shroud of mystery still surrounds this large-scale flow, given that its measurement using current helioseismic techniques is challenging. In this work we use results from 3D global simulations of solar convection to infer the dynamical behavior of the established meridional circulation. We make a direct comparison between the meridional circulation that arises in these simulations and the latest observations. Based on our results we argue that there should be an equatorward flow at the base of the convection zone at mid latitudes, below the current maximum depth helioseismic measures can probe (0.75 R). We also provide physical arguments to justify this behaviour. The simulations indicate that the meridional circulation undergoes substantial changes in morphology as the magnetic cycle unfolds. We close by discussing the importance of these dynamical changes for current methods of obse...

Passos, Dario; Miesch, Mark

2015-01-01T23:59:59.000Z

284

Magnetic Inhibition of Convection and the Fundamental Properties of Low-Mass Stars. I. Stars with a Radiative Core  

E-Print Network (OSTI)

Magnetic fields are hypothesized to inflate the radii of low-mass stars---defined as less massive than 0.8 solar masses---in detached eclipsing binaries (DEBs). We investigate this hypothesis using the recently introduced magnetic Dartmouth stellar evolution code. In particular, we focus on stars thought to have a radiative core and convective outer envelope by studying in detail three individual DEBs: UV Psc, YY Gem, and CU Cnc. The results suggest that the stabilization of thermal convection by a magnetic field is a plausible explanation for the observed model-radius discrepancies. However, surface magnetic field strengths required by the models are significantly stronger than those estimated from the observed coronal X-ray emission. Agreement between model predicted surface magnetic field strengths and those inferred from X-ray observations can be found by assuming that the magnetic field sources its energy from convection. This approach makes the transport of heat by convection less efficient and is akin ...

Feiden, Gregory A

2013-01-01T23:59:59.000Z

285

Overlooked sedimentary particles from tropical weathering environments  

Science Journals Connector (OSTI)

...Island, Solimoes River, Brazil. B: Thin-section...Negro and Soli- m es, Brazil: Implications for the...modern sand along a high-energy tropical coast: Baixada...gu , Rio de Janeiro, Brazil: Journal of South American...of the Environment and Renewable Natural Resources, and...

286

Impacts of Microphysical Scheme on Convective and Stratiform Characteristics in Two High Precipitation Squall Line Events  

SciTech Connect

This study investigates the impact of snow, graupel, and hail processes on the simulated squall lines over the Southern Great Plains in the United States. Weather Research and Forecasting (WRF) model is used to simulate two squall line events in May 2007, and the results are validated against radar and surface observations in Oklahoma. Several microphysics schemes are tested in this study, including WRF 5-Class Microphysics Scheme (WSM5), WRF 6-Class Microphysics Scheme (WSM6), Goddard Three Ice scheme (Goddard 3-ice) with graupel, Goddard Two Ice scheme (Goddard 2-ice), and Goddard 3-ice hail scheme. The simulated surface precipitation is sensitive to the microphysics scheme, and especially to whether graupel or hail category is included. All of the three ice (3-ice) schemes overestimated the total precipitation, within which WSM6 has the highest overestimation. Two ice (2-ice) schemes, missing a graupel/hail category, produced less total precipitation than 3-ice schemes. By applying a radar-based convective/stratiform partitioning algorithm, we find that by including the graupel/hail processes, there is an increase in areal coverage, precipitation intensity, updraft and downdraft intensity in convective region and a reduction of areal coverage and its precipitation intensity in stratiform region. For vertical structures, all the bulk schemes, especially 2-ice schemes, have the highest reflectivity located at upper levels (~8 km), which is unrealistic compared to observations. In addition, this study shows the radar-based convective/stratiform partitioning algorithm can reasonably identify WRF simulated precipitation, wind and microphysics fields in both convective and stratiform regions.

Wu, Di; Dong, Xiquan; Xi, Baike; Feng, Zhe; Kennedy, Aaron; Mullendore, Gretchen; Gilmore, Matthew; Tao, Wei-Kuo

2013-10-04T23:59:59.000Z

287

International Crops Research Institute for the Semi Arid Tropics | Open  

Open Energy Info (EERE)

Crops Research Institute for the Semi Arid Tropics Crops Research Institute for the Semi Arid Tropics Jump to: navigation, search Name International Crops Research Institute for the Semi-Arid Tropics Place India Sector Biofuels Product Biofuels ( Academic / Research foundation ) References International Crops Research Institute for the Semi-Arid Tropics[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. International Crops Research Institute for the Semi-Arid Tropics is a company located in India . References ↑ "International Crops Research Institute for the Semi-Arid Tropics" Retrieved from "http://en.openei.org/w/index.php?title=International_Crops_Research_Institute_for_the_Semi_Arid_Tropics&oldid=347036

288

Divergent subcritical convection in magnetized plasma from asymmetric sourcing  

SciTech Connect

Asymmetric particle and heat sourcing in a plasma confined in a closed magnetic field line configuration results in convection cells, as is well known. This phenomenon occurs even if the sourcing on average produces density and temperature profiles that are subcritical, i.e., magnetohydrodynamically stable to interchange modes. Such subcritical convection is expected to be small compared to the convection from supercritical driving for which the system is interchange unstable. The ratio of subcritical to supercritical convection is expected to scale as the inverse Reynolds numbers (for large Reynolds numbers). It is shown that this ratio is, in fact, considerably larger. As marginal stability is approached, the subcritical convection grows from very small to almost the unstable convection size, i.e., of order unity. This effect may be similar to why a driven, damped harmonic oscillator increases in amplitude as resonance is approached. A numerical simulation is done to demonstrate this effect. It is also shown that transport from the large convection can be substantial.

Adler, D.T.; Hassam, A.B. [Department of Physics, University of Maryland, College Park, Maryland 20742 (United States)

2005-06-15T23:59:59.000Z

289

Lattice Boltzmann method for double-diffusive natural convection  

Science Journals Connector (OSTI)

A lattice Boltzmann method for double-diffusive natural convection is presented. The model combines a multicomponent lattice Boltzmann scheme with a finite-difference solution of the energy equation to simulate natural convection caused by gradients in temperature and concentration. The model is validated both in two and three dimensions, and the agreement with literature data is satisfactory. A case study of thermosolutal convection of air in a cubical enclosure with horizontal thermal and solutal gradients is presented, exhibiting a rich variety of flow structures.

F. Verhaeghe; B. Blanpain; P. Wollants

2007-04-12T23:59:59.000Z

290

The Convective and Orographically Induced Precipitation Study (COPS): The Scientific Strategy, the Field Phase, and Research Highlights  

SciTech Connect

Within the frame of the international field campaign COPS (Convective and Orographically-induced Precipitation Study), a large suite of state-of-the-art meteorological instrumentation was operated, partially combined for the first time. The COPS field phase was performed from 01 June - 31 August 2007 in a low-mountain area in southwestern Germany/eastern France covering the Vosges Mountains, the Rhine valley and the Black Forest Mountains. The collected data set covers the entire evolution of convective precipitation events in complex terrain from their initiation, to their development and mature phase up to their decay. 18 Intensive Operation Periods (IOPs) with 34 operation days and 8 additional Special Observation Periods (SOPs) were performed providing a comprehensive data set covering different forcing conditions. In this paper an overview of the COPS scientific strategy, the field phase, and its first accomplishments is given. Some highlights of the campaign are illustrated with several measurement examples. It is demonstrated that COPS provided new insight in key processes leading to convection initiation and to the modification of precipitation by orography, in the improvement of QPF by the assimilation of new observations, and in the performance of ensembles of convection permitting models in complex terrain.

Wulfmeyer, Volker; Behrendt, Andreas; Kottmeir, Christoph; Corsmeier, Ulrich; Barthlott, Christian; Craig, George C.; Hagen, Martin; Althausen, Dietrich; Aoshima, Fumiko; Arpagaus, Marco; Bauer, Hans-Stefan; Bennett, Lindsay; Blyth, Alan; Brandau, Christine; Champollion, Cedric; Crewell, Susanne; Dick, Galina; di Girolamo, Paolo; Dorninger, Manfred; Dufournet, Yann; Eigenmann, Rafael; Engelmann, Ronny; Flamant, C.; Foken, Thomas; Gorgas, Theresa; Grzeschik, Matthias; Handwerker, Jan; Hauck, Christian; Holler, Hartmut; Junkermann, W.; Kalthoff, Norbert; Kiemle, Christoph; Klink, Stefan; Konig, Marianne; Krauss, Liane; Long, Charles N.; Madonna, Fabio; Mobbs, S.; Neininger, Bruno; Pal, Sandip; Peters, Gerhard; Pigeon, Gregoire; Richard, Evelyne; Rotach, Mathias W.; Russchenberg, Herman; Schwitalla, Thomas; Smith, Victoria; Steinacker, Reinhold; Trentman, Jorg; Turner, David D.; van Baelen, Joel; Vogt, Siegfried; Volkert, Hans; Weckwerth, Tammy; Wernli, Heini; Wieser, Andreas; Wirth, Martin

2011-02-24T23:59:59.000Z

291

Numerical and Experimental Modeling of Natural Convection for a Cryogenic Prototype of a Titan  

E-Print Network (OSTI)

in Sutherland's law D = diameter g = gravitation acceleration h = convection coefficient k = thermal

Colonius, Tim

292

Convective heat transfer characteristics of China RP-3 aviation kerosene at supercritical pressure  

E-Print Network (OSTI)

Convective heat transfer characteristics of China RP-3 aviation kerosene at supercritical pressure Keywords: Supercritical pressure Aviation kerosene Convective heat transfer Numerical study a b s t r a c convective in kerosene pipe flow is complicated. Here the convective heat transfer characteristics of China

Guo, Zhixiong "James"

293

Penetration of Convective Envelope into Stellar Core and Existence of Neutrino Loss  

Science Journals Connector (OSTI)

......the products of Penetration of Convective Envelope...convective mixing for any rate of the neutrino...superadiabaticity is determined Penetration of Convective Envelope...used.15> 459 the rate of Since the main...energy generation rate is sensitive to...smaller mass stars, penetration of convective envelope......

Ken'ichi Nomoto

1974-08-01T23:59:59.000Z

294

Heat transfer and convection onset in a compressible fluid:?3He near the critical point  

Science Journals Connector (OSTI)

Heat transport in 3He above its critical temperature Tc was studied along the critical isochore in a flat Rayleigh-Bénard cell (height h=1 mm, diameter D=57 mm). The range of the reduced temperature ? was 5×10-4fluid layer as a function of the time t was measured for different values of the heat current q until steady state was reached. The crossover was observed from the regime dominated by the Rayleigh criterion for the convection onset to that controlled by the adiabatic temperature gradient (ATG), or “Schwarzschild criterion,” in good quantitative agreement with predictions. The slope of the convective heat current versus the reduced Rayleigh number was found to be independent of compressibility and the same as for still less compressible fluids. Plots of Nu versus Ra, both corrected for the ATG effect, are presented for early-stage convective turbulence (1×105fluid is described, and the derivation for ?T(t) in the diffusive regime is outlined.

Andrei B. Kogan and Horst Meyer

2001-04-24T23:59:59.000Z

295

Chaotic mean wind in turbulent thermal convection and long-term correlations in solar activity  

E-Print Network (OSTI)

It is shown that correlation function of the mean wind velocity in a turbulent thermal convection (Rayleigh number $Ra \\sim 10^{11}$) exhibits exponential decay with a very long correlation time, while corresponding largest Lyapunov exponent is certainly positive. These results together with the reconstructed phase portrait indicate presence of a chaotic component in the examined mean wind. Telegraph approximation is also used to study relative contribution of the chaotic and stochastic components to the mean wind fluctuations and an equilibrium between these components has been studied. Since solar activity is based on the thermal convection processes, it is reasoned that the observed solar activity long-term correlations can be an imprint of the mean wind chaotic properties. In particular, correlation function of the daily sunspots number exhibits exponential decay with a very long correlation time and corresponding largest Lyapunov exponent is certainly positive, also relative contribution of the chaotic and stochastic components follows the same pattern as for the convection mean wind.

A. Bershadskii

2009-08-27T23:59:59.000Z

296

NPP Tropical Forest: Khao Chong, Thailand  

NLE Websites -- All DOE Office Websites (Extended Search)

Khao Chong, Thailand, 1962-1965 Khao Chong, Thailand, 1962-1965 [PHOTOGRAPH] Photograph: Eye-level view of forest interior at Khao Chong (click on the photo to view a series of images from this site) Data Citation Cite this data set as follows: Kira, T. 1998. NPP Tropical Forest: Khao Chong, Thailand, 1962-1965. Data set. Available on-line [http://www.daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. Description Productivity of a tropical rain forest was determined at the Khao Chong study site, under the auspices of the Joint Thai-Japanese Biological Expedition to South-East Asia. Biomass increment within a 40 m x 40 m study area for all trees greater than 4.5 cm dbh (diameter at breast height, 130 cm) was monitored between

297

NPP Tropical Forest: Manaus, Brazil [Amazonas]  

NLE Websites -- All DOE Office Websites (Extended Search)

Manaus, Brazil, 1963-1990 Manaus, Brazil, 1963-1990 Data Citation Cite this data set as follows: Piedade, M. T. F., and W. J. Junk. 2001. NPP Tropical Forest: Manaus, Brazil, 1963-1990. Data set. Available on-line [http://www.daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. Description Biomass and components of productivity for several types of tropical forest were determined for a number of study sites around Manaus, Brazil, from 1963 to the present. The study sites include several (0.2 ha) stands of terra firme (dry land) forest at " 64" to the northeast of Manaus, towards Itacoatiara (approximately 3.0 S 59.7 W, near the " Egler" Reserve), riverine forest in the 10 km x 10 km " Reserve" (2.95 S 59.95 W, 26 km

298

NPP Tropical Forest: Marafunga, Papua New Guinea  

NLE Websites -- All DOE Office Websites (Extended Search)

Marafunga, Papua New Guinea, 1970-1971 Marafunga, Papua New Guinea, 1970-1971 [PHOTOGRAPH] Photograph: Profile of tropical forest at Marafunga (click on the photo to view a series of images from this site) Data Citation Cite this data set as follows: Edwards, P. J., and P. J. Grubb. 1999. NPP Tropical Forest: Marafunga, Papua New Guinea, 1970-1971. Data set. Available on-line [http://www.daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. Description Biomass and nutrient content of different vegetation components and soil for a lower montane secondary rain forest were determined in 1970-71 at Marafunga in the highlands of Papua New Guinea. The only component of net primary production (NPP) determined at Marafunga was litterfall, although

299

NPP Tropical Forest: Magdalena Valley, Colombia  

NLE Websites -- All DOE Office Websites (Extended Search)

Magdalena Valley, Colombia, 1970-1971 Magdalena Valley, Colombia, 1970-1971 Data Citation Cite this data set as follows: Folster, H. 1999. NPP Tropical Forest: Magdalena Valley, Colombia, 1970-1971. Data set. Available on-line [http://www.daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. Description Biomass, litterfall, and nutrient content of above-ground vegetation and soil were determined for a tropical seasonal evergreen forest at Magdalena Valley, Colombia, during an 18-month period in 1970 and 1971. The study was sponsored by the German Research Foundation. Of primary interest were biomass and nutrient dynamics of a forest stand that had developed atop a perched water table on a typical valley terrace. Perched water tables give rise to pseudogley soils with low pH, prolonged

300

Experimental Investigation of Natural Convection in Trombe Wall Systems  

E-Print Network (OSTI)

In this paper, experiments with a passive solar building with Trombe wall in the north cold climate are carried out and discussed, and the natural convection heat transfer process has been investigated. The relativity of the factors affecting indoor...

Chen, B.; Zhao, J.; Chen, C.; Zhuang, Z.

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical convection observed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Ensemble Sensitivity Analysis Applied to a Southern Plains Convective Event  

Science Journals Connector (OSTI)

Forecast sensitivity of an April 2012 severe convection event in northern Texas is investigated with a high resolution Weather Research and Forecasting (WRF) model-based Ensemble Kalman Filter (EnKF). Through Ensemble Sensitivity Analysis (ESA), ...

Christopher N. Bednarczyk; Brian C. Ancell

302

Theory for induced convection experiments in the tokamak edge  

E-Print Network (OSTI)

Theory for induced convection experiments in the tokamak edge P. Helander1 , D.D. Ryutov2 , and R National Laboratory, Livermore, USA By biasing alternate divertor plates in a tokamak, one can create

303

Initiating Moist Convection in an Inhomogeneous Layer by Uniform Ascent  

Science Journals Connector (OSTI)

Using aircraft data from the recent Dominica Experiment (DOMEX) project in Dominica, the authors evaluate a modified version of Woodcock’s theory of moist convective initiation. Upstream of Dominica, anticorrelated fluctuations in temperature and ...

Alison D. Nugent; Ronald B. Smith

2014-12-01T23:59:59.000Z

304

Effects of aerosols on deep convective cumulus clouds  

E-Print Network (OSTI)

This work investigates the effects of anthropogenic aerosols on deep convective clouds and the associated radiative forcing in the Houston area. The Goddard Cumulus Ensemble model (GCE) coupled with a spectral-bin microphysics is employed...

Fan, Jiwen

2009-05-15T23:59:59.000Z

305

Scaling Laws for the Heterogeneously Heated Free Convective Boundary Layer  

Science Journals Connector (OSTI)

The heterogeneously heated free convective boundary layer (CBL) is investigated by means of dimensional analysis and results from large-eddy simulations (LES) and direct numerical simulations (DNS). The investigated physical model is a CBL that ...

Chiel C. van Heerwaarden; Juan Pedro Mellado; Alberto De Lozar

2014-11-01T23:59:59.000Z

306

A Unified Convection Scheme (UNICON). Part I: Formulation  

Science Journals Connector (OSTI)

The author develops a unified convection scheme (UNICON) that parameterizes relative (i.e., with respect to the grid-mean vertical flow) subgrid vertical transport by nonlocal asymmetric turbulent eddies. UNICON is a process-based model of subgrid ...

Sungsu Park

2014-11-01T23:59:59.000Z

307

Representing Forecast Error in a Convection-Permitting Ensemble System  

Science Journals Connector (OSTI)

Ensembles provide an opportunity to greatly improve short-term prediction of local weather hazards, yet generating reliable predictions remain a significant challenge. In particular, convection-permitting ensemble forecast systems (CPEFSs) have ...

Glen S. Romine; Craig S. Schwartz; Judith Berner; Kathryn R. Fossell; Chris Snyder; Jeff L. Anderson; Morris L. Weisman

2014-12-01T23:59:59.000Z

308

Convective stability of carbon sequestration in anisotropic porous media  

Science Journals Connector (OSTI)

...Convective stability of carbon sequestration in anisotropic porous media...media|stability theory|carbon sequestration| 1. Introduction The world's...processes occurring during carbon dioxide sequestration in underground saline aquifers...

2014-01-01T23:59:59.000Z

309

Land-atmosphere interaction and radiative-convective equilibrium  

E-Print Network (OSTI)

I present work on several topics related to land-atmosphere interaction and radiative-convective equilibrium: the first two research chapters invoke ideas related to land-atmosphere interaction to better understand ...

Cronin, Timothy (Timothy Wallace)

2014-01-01T23:59:59.000Z

310

Interaction between surface and atmosphere in a convective boundary layer /  

E-Print Network (OSTI)

heat, and thermal conductivity of the ground and grid sizegrid was stretched uniformly to 0.1 m resolution. The heatheat flux) are friction velocity and convective velocity respectively. The grid

Garai, Anirban

2013-01-01T23:59:59.000Z

311

Large-Scale Distinctions between MJO and Non-MJO Convective Initiation over the Tropical Indian Ocean  

E-Print Network (OSTI)

Ocean JIAN LING Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, Florida of Marine and Atmospheric Science, University of Miami, Miami, Florida PETER BECHTOLD European Centre discharge­recharge processes (Hendon 1988; Blade and Hartmann 1993; Kemball-Cook and Weare 2001

Zhang, Chidong

312

The Convective Instability Pathway to Warm Season Drought in Texas. Part I: The Role of Convective Inhibition and Its Modulation by Soil Moisture  

Science Journals Connector (OSTI)

This research is designed to investigate how convective instability influences monthly mean precipitation in Texas in the summertime and to examine the modulation of convective instability and precipitation by local and regional forcings. Since ...

Boksoon Myoung; John W. Nielsen-Gammon

2010-09-01T23:59:59.000Z

313

Characterization of Throughfall Heterogeneity in a Tropical Pre-Montane Could Forest in Costa Rica  

E-Print Network (OSTI)

American tropics are valued for their rich biodiversity, pristine forests, and hydroelectric potential (Chang and Lau, 1983). However, growing populations and ecotourism put stress on their water resources. The increase in water demand and land... to December. Differences in observed seasonality are due to differences in locations, year-to-year variability, and degree of seasonality (Chazdon and Fetcher, 1984). Over the past decade, Costa Rica has seen an increase in ecotourism, particularly during...

Berger, Amelie Cecile

2013-09-26T23:59:59.000Z

314

The Hadley Circulation as a Radiative–Convective Instability  

Science Journals Connector (OSTI)

Hadley cell simulations over a tropical ocean are reported that suggest that the emission and absorption of thermal radiation by clouds plays an important role in the dynamics of the Hadley circulation. In particular, inclusion of interactions ...

David J. Raymond

2000-05-01T23:59:59.000Z

315

UDC 551.613.1:551.511.33:551.509.313(213) Response of the Tropical Atmosphere  

E-Print Network (OSTI)

study of the tropical atmosphere. From analyses of wind data in the lower stratosphere over considers lateral coupling with higher latitude energy sources as the most important driving force are of an observational nature. Kidson et al. (1969) studied the statistical properties of both the steady and transient

Webster, Peter J.

316

Dynamic Transitions of Surface Tension Driven Convection  

E-Print Network (OSTI)

We study the well-posedness and dynamic transitions of the surface tension driven convection in a three-dimensional (3D) rectangular box with non-deformable upper surface and with free-slip boundary conditions. It is shown that as the Marangoni number crosses the critical threshold, the system always undergoes a dynamic transition. In particular, two different scenarios are studied. In the first scenario, a single mode losing its stability at the critical parameter gives rise to either a Type-I (continuous) or a Type-II (jump) transition. The type of transitions is dictated by the sign of a computable non-dimensional parameter, and the numerical computation of this parameter suggests that a Type-I transition is favorable. The second scenario deals with the case where the geometry of the domain allows two critical modes which possibly characterize a hexagonal pattern. In this case we show that the transition can only be either a Type-II or a Type-III (mixed) transition depending on another computable non-dimensional parameter. We only encountered Type-III transition in our numerical calculations. The second part of the paper deals with the well-posedness and existence of global attractors for the problem.

Henk Dijkstra; Taylan Sengul; Shouhong Wang

2011-05-05T23:59:59.000Z

317

Novel biodiversity of natural products-producing tropical marine cyanobacteria.  

E-Print Network (OSTI)

??During the last three decades, tropical marine cyanobacteria have emerged as an extraordinarily prolific source of promising biomedical natural products (NPs). Creative endeavors have been… (more)

Engene, Niclas

2011-01-01T23:59:59.000Z

318

Clarence Strait Tidal Energy Project, Tenax Energy Tropical Tidal...  

Open Energy Info (EERE)

Energy Tropical Tidal Test Centre, Jump to: navigation, search 1 Retrieved from "http:en.openei.orgwindex.php?titleClarenceStraitTidalEnergyProject,TenaxEnergyTropica...

319

Ocean dynamics and thermodynamics in the tropical Indo- Pacific region.  

E-Print Network (OSTI)

??The Indonesian archipelago links the tropical Indian and western Pacific Oceans, so transmission of oceanic and atmospheric energy across the archipelago has the potential to… (more)

Drushka, Kyla

2011-01-01T23:59:59.000Z

320

Validating Atmospheric Reanalysis Data Using Tropical Cyclones as Thermometers  

Science Journals Connector (OSTI)

Capsule: Tropical cyclones are used as traveling thermometers to globally sample upper-tropospheric temperatures and help mitigate uncertainties due to discrepancies among different reanalysis data products.

James P. Kossin

Note: This page contains sample records for the topic "tropical convection observed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Carbon sequestration potential of tropical pasture compared with afforestation in Panama  

E-Print Network (OSTI)

Carbon sequestration potential of tropical pasture compared with afforestation in Panama S E B) to estimate the carbon sequestration potential of tropical pasture compared with afforestation; and (3 show the potential for considerable carbon sequestration of tropical afforestation and highlight

Potvin, Catherine

322

MAGNETIC CYCLES IN A CONVECTIVE DYNAMO SIMULATION OF A YOUNG SOLAR-TYPE STAR  

SciTech Connect

Young solar-type stars rotate rapidly and many are magnetically active. Some appear to undergo magnetic cycles similar to the 22 yr solar activity cycle. We conduct simulations of dynamo action in rapidly rotating suns with the three-dimensional magnetohydrodynamic anelastic spherical harmonic (ASH) code to explore dynamo action achieved in the convective envelope of a solar-type star rotating at five times the current solar rotation rate. We find that dynamo action builds substantial organized global-scale magnetic fields in the midst of the convection zone. Striking magnetic wreaths span the convection zone and coexist with the turbulent convection. A surprising feature of this wreath-building dynamo is its rich time dependence. The dynamo exhibits cyclic activity and undergoes quasi-periodic polarity reversals where both the global-scale poloidal and toroidal fields change in sense on a roughly 1500 day timescale. These magnetic activity patterns emerge spontaneously from the turbulent flow and are more organized temporally and spatially than those realized in our previous simulations of the solar dynamo. We assess in detail the competing processes of magnetic field creation and destruction within our simulations that contribute to the global-scale reversals. We find that the mean toroidal fields are built primarily through an {Omega}-effect, while the mean poloidal fields are built by turbulent correlations which are not well represented by a simple {alpha}-effect. During a reversal the magnetic wreaths propagate toward the polar regions, and this appears to arise from a poleward propagating dynamo wave. As the magnetic fields wax and wane in strength and flip in polarity, the primary response in the convective flows involves the axisymmetric differential rotation which varies on similar timescales. Bands of relatively fast and slow fluid propagate toward the poles on timescales of roughly 500 days and are associated with the magnetic structures that propagate in the same fashion. In the Sun, similar patterns are observed in the poleward branch of the torsional oscillations, and these may represent poleward propagating magnetic fields deep below the solar surface.

Brown, Benjamin P. [Department of Astronomy, University of Wisconsin, Madison, WI 53706-1582 (United States); Miesch, Mark S. [High Altitude Observatory, NCAR, Boulder, CO 80307-3000 (United States); Browning, Matthew K. [Canadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, ON M5S3H8 (Canada); Brun, Allan Sacha [Laboratoire AIM Paris-Saclay, CEA/Irfu Universite Paris-Diderot CNRS/INSU, 91191 Gif-sur-Yvette Cedex (France); Toomre, Juri, E-mail: bpbrown@astro.wisc.edu [JILA and Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309-0440 (United States)

2011-04-10T23:59:59.000Z

323

Sensitivity of Typhoon Forecasts to Different Subsets of Targeted Dropsonde Observations  

Science Journals Connector (OSTI)

For the first time, joint tropical cyclone (TC) surveillance missions by several aircraft were conducted in the western North Pacific basin within the framework of The Observing System Research and Predictability Experiment (THORPEX) Pacific ...

Florian Harnisch; Martin Weissmann

2010-07-01T23:59:59.000Z

324

Microphysical characteristics of clouds and precipitation during pre-monsoon and monsoon period over a tropical Indian station  

Science Journals Connector (OSTI)

Characteristics of clouds and precipitation during the pre-monsoon (PM) and monsoon months (MM) have been examined in the present study over the tropical station Kolkata (22.65°N, 88.45°E), which is located in the eastern part of India. Satellite data of clouds for the years 2005–2007 and raindrop size distributions (DSD) derived from ground-based Disdrometer for the years 2005 and 2006 for PM and MM has been considered here. Results shows that lower and middle level clouds dominate in the pre-monsoon season and the higher-level clouds are predominant in the monsoon season over the mentioned region. Correspondingly the cloud effective radius value also increases from the pre-monsoon to the monsoon months. The impact of aerosols and moisture plays a vital role in such changes. The characteristics of raindrop size distribution for the two seasons also showed that larger drops are more prevalent during pre-monsoon season whereas the smaller drops are present in larger number in the monsoon months. This is mainly due to the convective nature of rainfall in the pre-monsoon months, where intense convection, accompanied by strong updrafts modifies the raindrops. Thus pre-monsoon (monsoon) season over Kolkata region is characterized by lower/middle level (higher level) clouds, smaller (larger) cloud drop size and larger (smaller) raindrop size at the surface.

Kaustav Chakravarty; P. Ernest Raj; Aniruddha Bhattacharya; Animesh Maitra

2013-01-01T23:59:59.000Z

325

Capinha et al.: Zonitoides in tropical mountain forests Susceptibility of tropical mountain forests to biological invasions  

E-Print Network (OSTI)

vegetation (e.g., Kappes, 2006; Kappes et al., 2009), and the (subsequent) use of alien plants modeling suggests that both taxa could be widely distributed in the mountains of tropical South America and Africa. Z. arboreus finds suitable climates in many places in SE Asia and especially at many conservation

Pereira, Henrique Miguel

326

Isotopic composition of water in the tropical tropopause layer in cloudresolving simulations of an idealized tropical circulation  

E-Print Network (OSTI)

that both the sublimation of relatively enriched ice associated with deep convection and fractionation role in the climate and chemistry of the stratosphere and also of the Earth as a whole [e.g., Forster convection through the injection and subsequent sublimation of ice [e.g., Corti et al., 2008], dehydration

Romps, David M.

327

Climate change and tropical biodiversity: a new focus  

E-Print Network (OSTI)

Climate change and tropical biodiversity: a new focus Jedediah Brodie1 , Eric Post2 and William F, Australia Considerable efforts are focused on the consequences of climate change for tropical rainforests climatic changes and human land use) remain understudied. Key concerns are that aridification could

Wisenden, Brian D.

328

Error propagation and scaling for tropical forest biomass estimates  

Science Journals Connector (OSTI)

...propagation and scaling for tropical forest biomass estimates Jerome Chave 1 * Richard Condit...34002-0948, USA The above-ground biomass (AGB) of tropical forests is a crucial...inferences about long-term changes in biomass stocks, it is essential to know the uncertainty...

2004-01-01T23:59:59.000Z

329

TROPICAL CYCLONE RESEARCH REPORT TCRR 2: 131 (2013)  

E-Print Network (OSTI)

circulation (e.g., Marks and Shay 1998). There have been considerable advances in computer technology overTROPICAL CYCLONE RESEARCH REPORT TCRR 2: 1­31 (2013) Meteorological Institute Ludwig Maximilians University of Munich Paradigms for tropical cyclone intensification Michael T. Montgomerya 1 and Roger K

Smith, Roger K.

330

Hybrid coupled modeling of the tropical Pacific using neural networks  

E-Print Network (OSTI)

Hybrid coupled modeling of the tropical Pacific using neural networks Shuyong Li, William W. Hsieh To investigate the potential for improving hybrid coupled models (HCM) of the tropical Pacific by the use: dynamical coupled models, statistical models and hybrid coupled models [Barnston et al., 1994]. A hybrid

Hsieh, William

331

Chapter Number1 Biomass Prediction in Tropical Forests:2  

E-Print Network (OSTI)

Chapter Number1 Biomass Prediction in Tropical Forests:2 The Canopy Grain Approach3 Christophe France9 1. Introduction10 The challenging task of biomass prediction in dense and heterogeneous tropical different forest structures may indeed present similar above ground biomass (AGB) values.13 This is probably

Paris-Sud XI, Université de

332

The Energy Department Prepares for Tropical Storm Karen | Department of  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

The Energy Department Prepares for Tropical Storm Karen The Energy Department Prepares for Tropical Storm Karen The Energy Department Prepares for Tropical Storm Karen October 4, 2013 - 3:00pm Addthis Marissa Newhall Marissa Newhall Managing Editor, Energy.gov What does this mean for me? Follow the latest news on Tropical Storm Karen by visiting the FEMA blog. Stay up-to-date on energy delivery impacts by reading twice-daily situation reports from the Energy Department. Visit ready.gov for more information about emergency preparedness. Editor's note: As of Monday, October 7, 2013, Energy Department reporting about Tropical Storm Karen has concluded, and no additional situation reports will be posted. The Department of Energy (DOE) is working closely with the Federal Emergency Management Agency (FEMA) and in support of state and local

333

The kinematic and cloud-to-ground lightning structure of the 9-10, June 1998 Red River Mesoscale Convective System  

E-Print Network (OSTI)

An investigation of the kinematic and electrical properties of the 9-10 June, 1998 Red River Mesoscale Convective System (MCS), as observed by the NOAA P3 Tail Radar and the National Lightning Detection Network, is presented. This system exhibits...

Santarpia, Joshua

2012-06-07T23:59:59.000Z

334

A dual mass flux framework for boundary layer convection  

NLE Websites -- All DOE Office Websites (Extended Search)

A dual mass flux framework for boundary layer convection A dual mass flux framework for boundary layer convection Neggers, Roel European Centre for Medium-range Weather Forecasts (ECMWF) Category: Modeling A new convective boundary layer scheme is presented that is currently being developed for the Integrated Forecasting System (IFS) of the European Centre for Medium-range Weather Forecasts (ECMWF). Part of the total turbulent flux is modeled through advective mass flux by multiple updrafts, initialized at the surface. Two groups of updrafts are explicitly represented; i) updrafts that never reach their lifting condensation level, and ii) updrafts that condensate and become cloudy. Key new ingredient is the flexibility of the associated updraft area fractions, as a function of model state. As a result, an extra degree of freedom is introduced in the

335

Natural Convection Shutdown Heat Removal Test Facility (NSTF)  

NLE Websites -- All DOE Office Websites (Extended Search)

Natural Convection Natural Convection Shutdown Heat Removal Test Facility Scaling Basis Full Scale Half Scale NSTF Argonne National Laboratory's Natural Convection Shutdown Heat Removal Test Facility (NSTF) - one of the world's largest facilities for ex-vessel passive decay heat removal testing-confirms the performance of reactor cavity cooling systems (RCCS) and similar passive confinement or containment decay heat removal systems in modern Small Modular Reactors. Originally built to aid in the development of General Electric's Power Reactor Innovative Small Module (PRISM) Reactor Vessel Auxiliary Cooling System (RVACS), the NSTF has a long history of providing confirmatory data for the airside of the RVACS. Argonne National Laboratory's NSTF is a state-of-the-art, large-scale facility for evaluating performance

336

ARM - Midlatitude Continental Convective Clouds (comstock-hvps)  

DOE Data Explorer (OSTI)

Convective processes play a critical role in the Earth's energy balance through the redistribution of heat and moisture in the atmosphere and their link to the hydrological cycle. Accurate representation of convective processes in numerical models is vital towards improving current and future simulations of Earths climate system. Despite improvements in computing power, current operational weather and global climate models are unable to resolve the natural temporal and spatial scales important to convective processes and therefore must turn to parameterization schemes to represent these processes. In turn, parameterization schemes in cloud-resolving models need to be evaluated for their generality and application to a variety of atmospheric conditions. Data from field campaigns with appropriate forcing descriptors have been traditionally used by modelers for evaluating and improving parameterization schemes.

Jensen, Mike; Comstock, Jennifer; Genio, Anthony Del; Giangrande, Scott; Kollias, Pavlos

337

Pseudosteady-state mixed convection inside rotating spherical containers  

SciTech Connect

A computational study of the pseudosteady-state two-dimensional mixed convection within rotating spherical containers is presented. The computations are based on an iterative, finite-volume numerical procedure using primitive dependent variables, whereby the time-dependent continuity, momentum and energy equations in the spherical coordinate system are solved. Natural convection effect is modeled via the Boussinesq approximation. For a fixed Prandtl number of 4.62, parametric studies were performed by varying the Rayleigh number in order to cover the laminar regime adequately. For a given Rayleigh number, the ratio of Gr/Re{sup 2} was varied between 0.1 and 10. Given a Rayleigh number, the streamline patterns maintain their general shape with a dominant rotating vortex. As the forced convection effect becomes less marked, the streamlines exhibit less pronounced gradients near the surface of the sphere. As the rotational effect become more marked, the extent of the deviation from the limiting case of non-rotating spheres becomes more noticed. However, the bottom of the sphere still remains to be the region with enhanced heat transfer. Given a rotational Reynolds number, the streamline patterns are not affected greatly as the natural convection is promoted, however the temperature gradients near the surface are markedly enhanced. It is noticed that as natural convection effects are promoted, the greater portion of the sphere's surface experiences enhanced heat transfer rates. Given a Rayleigh number, the contours of the azimuthal velocity exhibit a nearly vertical equally-spaced pattern suggesting that solid-body rotation for high rotational Reynolds numbers. However, as the natural convection effects are enhanced, the contours become more slanted. The variation of the mean Nusselt number with the Reynolds and Rayleigh numbers is also quantified.

Khodadadi, J.M.; Li, W.; Shi, X.

1999-07-01T23:59:59.000Z

338

Convective exergy losses of developing slip flow in microchannels  

Science Journals Connector (OSTI)

A numerical formulation of convective exergy losses in microchannels is developed. Using a new convection model (called Non-Inverted Skew Upwind Scheme (NISUS)), the predicted velocity field is post-processed to determine frictional irreversibilities within the microchannel. Boundary conditions are established from a first-order slip velocity, based on streamwise temperature gradients and transverse velocity gradients at the wall. Parametric studies are conducted for varying flow rates, channel aspect ratios, slip coefficients and pressure ratios across the microchannel. The predicted exergy destruction results provide useful new data, from which design modifications can be made to reduce power input when transporting fluid through a microchannel.

E.O.B. Ogedengbe; G.F. Naterer; M.A. Rosen

2007-01-01T23:59:59.000Z

339

Convection Initiation along Soil Moisture Boundaries in the Southern Great Plains  

Science Journals Connector (OSTI)

Boundaries between two dissimilar air masses have been shown to be the focus region for convection initiation. One feature that has been shown to create these boundaries, as well as mesoscale circulation patterns conducive for convection, is soil ...

John D. Frye; Thomas L. Mote

2010-04-01T23:59:59.000Z

340

Lateral Heat Exchange after the Labrador Sea Deep Convection in 2008  

Science Journals Connector (OSTI)

The mechanisms through which convected water restratifies in the Labrador Sea are still under debate. The Labrador Sea restratification after deep convection in the 2007/08 winter is studied with an eddy-resolving numerical model. The modeled ...

Weiwei Zhang; Xiao-Hai Yan

2014-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical convection observed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Convective heat transfer in the nonstationary motion of a Maxwellian fluid between parallel planes  

Science Journals Connector (OSTI)

The convective heat-transfer problem is investigated for a Maxwellian fluid in generalized Couette flow in the case...

Z. P. Shul'man; É. A. Zal'tsgendler

1970-06-01T23:59:59.000Z

342

Boussinesq convection and motions of boundary spheres in a rotating spherical shell  

E-Print Network (OSTI)

RIMS­1772 Boussinesq convection and motions of boundary spheres in a rotating spherical shell #12; Boussinesq convection and motions of boundary spheres in a rotating spherical shell Keiji Kimura; Abstract Boussinesq thermal convection in rotating spheres or spherical shells has been investigated

343

Boussinesq convection and motions of boundary spheres in a rotating spherical shell  

E-Print Network (OSTI)

RIMS-1772 Boussinesq convection and motions of boundary spheres in a rotating spherical shell #12;Boussinesq convection and motions of boundary spheres in a rotating spherical shell Keiji Kimura Boussinesq thermal convection in rotating spheres or spherical shells has been investigated for over half

344

Evolution du contenu physique 1. Nouveau bloc couche limite convection nuages (nouvelle physique)  

E-Print Network (OSTI)

Evolution du contenu physique 1. Nouveau bloc couche limite ­ convection ­ nuages (nouvelle physique) ON DISPOSE D'UN NOUVEAU CADRE DE TRAVAIL. ?? - Convection /relief (Jean-Yves Grandpeix, Jingmei Yu, Alain Lahelec) ++ - glace dans la convection (Arnaud Jam, Jean-Yves Grandpeix) ?? - Modèle micro-physique

Madeleine, Jean-Baptiste

345

Review of fluid flow and convective heat transfer within rotating disk cavities  

E-Print Network (OSTI)

Review of fluid flow and convective heat transfer within rotating disk cavities with impinging jet * Corresponding author : souad.harmand@univ-valenciennes.fr Abstract Fluid flow and convective heat transfer, are treated in details in this review. The review focuses on convective heat transfer in predominantly outward

Boyer, Edmond

346

Life Cycle of a Mesoscale Circular Gust Front Observed by a C-Band Doppler Radar in West Africa  

E-Print Network (OSTI)

On 10 July 2006, during the Special Observation Period (SOP) of the African Monsoon Multidisciplinary Analysis (AMMA) campaign, a small convective system initiated over Niamey and propagated westward in the vicinity of ...

Lothon, Marie

347

Numerical analysis of binary fluid convection in extended systems  

E-Print Network (OSTI)

arising in the primary subcritical bifurcation. The dynamics triggered by Eckhaus instability is discussed mixtures. For such mixtures, the onset of convection is via a subcritical Hopf bifurcation that gives rise of S. In the case of the experiment reported in [2] a S = -0.257 water-ethanol mixture is used. A final

Batiste, Oriol

348

A numerical study of convection with an ambient wind field  

E-Print Network (OSTI)

. The citations on the following pages follow the style of the Journal of the Atmos heric Sciences. Orville (1968) constructed a convective model based on the same equations as those used by Assi. He concerned himself with the development of cumulus clouds over...

Cottrell, Kit Garfield

1970-01-01T23:59:59.000Z

349

Constraints on mantle convection from seismic tomography and flow modeling  

E-Print Network (OSTI)

In this thesis I combine high resolution seismic tomography and realistic flow modeling to constrain mantle convection. The bulk of the data used in the tomographic imaging are millions of P, pP and pwP travel time residuals, ...

Kárason, Hrafnkell, 1970-

2002-01-01T23:59:59.000Z

350

The Influence of Wind Speed on Shallow Marine Cumulus Convection  

Science Journals Connector (OSTI)

The role of wind speed on shallow marine cumulus convection is explored using large-eddy simulations and concepts from bulk theory. Focusing on cases characteristic of the trades, the equilibrium trade wind layer is found to be deeper at stronger ...

Louise Nuijens; Bjorn Stevens

2012-01-01T23:59:59.000Z

351

Toward the Long-range Prediction of Severe Convective Windstorms  

E-Print Network (OSTI)

thunderstorm systems (or mesoscale convective system (MCS)), cause major disruption to society, including widespread power outages, tree and structural damage, and transportation accidents that affect multi- state � Left five million without power � Traveled 700 miles in 12 hours #12;June 2012 Derecho Overview http

Kuligowski, Bob

352

Self-organization of local magnetoplasma structures in the upper layers of the solar convection zone  

SciTech Connect

Self-organization and evolution of magnetoplasma structures in the upper layers of the solar convection zone are discussed as a process of diffuse aggregation of magnetic flux tubes. Equations describing the tube motion under the action of magnetic interaction forces, hydrodynamic forces, and random forces are written explicitly. The process of aggregation of magnetic flux tubes into magnetic flux clusters of different shapes and dimensions is simulated numerically. The obtained structures are compared with the observed morphological types of sunspot groups. The quantitative comparison with the observational data was performed by comparing the fractal dimensions of the photospheric magnetic structures observed in solar active regions with those of structures obtained in the numerical experiment. The model has the following free parameters: the numbers of magnetic flux tubes with opposite polarities on the considered area element (Nn and Ns), the average radius of the cross section of the magnetic flux tube (a), its effective length (l), the twist factor of the tube field (k), and the absolute value of the average velocity of chaotic tube displacements (d). Variations in these parameters in physically reasonable limits leads to the formation of structures (tube clusters of different morphological types) having different fractal dimensions. Using the NOAA 10488 active region, which appeared and developed into a complicated configuration near the central meridian, as an example, it is shown that good quantitative agreement between the fractal dimensions is achieved at the following parameters of the model: Nn = Ns = 250 ± 50; a = 150 ± 50 km; l ? 5000 km, and d = 80 ± 10 m/s. These results do not contradict the observational data and theoretical estimates obtained in the framework of the Parker “spaghetti” model and provide new information on the physical processes resulting in the origin and evolution of local magnetic plasma structures in the near-photospheric layers of the solar convection zone.

Chumak, O. V., E-mail: chuo@yandex.ru [Moscow State University, Sternberg Astronomical Institute (Russian Federation)

2013-08-15T23:59:59.000Z

353

A Comparison of Precipitation Forecast Skill between Small Convection-Allowing and Large Convection-Parameterizing Ensembles  

E-Print Network (OSTI)

Submitted to Weather and Forecasting in October 2008, Accepted in January 2009 * Corresponding author) Weather Research and Forecasting (WRF) model ensemble, which cover a similar domain over the central-convection resolution (PCR) ensembles. Computation of various precipitation skill metrics for probabilistic

Droegemeier, Kelvin K.

354

ARM - Field Campaign - Tropical Ocean Global Atmosphere Coupled  

NLE Websites -- All DOE Office Websites (Extended Search)

govCampaignsTropical Ocean Global Atmosphere Coupled Ocean-Atmosphere govCampaignsTropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Exp Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign : Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Exp 1992.07.11 - 1993.02.28 Lead Scientist : Chuck Long Data Availability Final data available. For data sets, see below. Summary IOP completed. Description The Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (TOGA-COARE) was conducted to better understand the structure of the coupled system of the warm pool of the western Pacific Ocean. Hundreds of participants from dozens of countries took part in this experiment from November 1, 1992 through February 28, 1993. Campaign Data Sets

355

Lunty Tropical Fish Aquaculture Low Temperature Geothermal Facility | Open  

Open Energy Info (EERE)

Lunty Tropical Fish Aquaculture Low Temperature Geothermal Facility Lunty Tropical Fish Aquaculture Low Temperature Geothermal Facility Jump to: navigation, search Name Lunty Tropical Fish Aquaculture Low Temperature Geothermal Facility Facility Lunty Tropical Fish Sector Geothermal energy Type Aquaculture Location Buhl, Idaho Coordinates 42.5990714°, -114.7594946° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[]}

356

Benefits of Tropical Forest Management Under the New Climate Change  

Open Energy Info (EERE)

Benefits of Tropical Forest Management Under the New Climate Change Benefits of Tropical Forest Management Under the New Climate Change Agreement-A Case Study in Cambodia Jump to: navigation, search Name Benefits of Tropical Forest Management Under the New Climate Change Agreement-A Case Study in Cambodia Agency/Company /Organization United States Agency for International Development, Global Environment Facility, United Nations Development Programme Sector Land Focus Area Forestry Topics Policies/deployment programs, Background analysis Resource Type Lessons learned/best practices Website http://www.forestcarbonportal. Country Cambodia UN Region South-Eastern Asia References REDD Cambodia Case Study[1] Benefits of Tropical Forest Management Under the New Climate Change Agreement-A Case Study in Cambodia Screenshot

357

Tropical air mass modification over water (Gulf of Mexico Region)  

E-Print Network (OSTI)

TROPICAL AIR MASS MODIFICATION OVER WA~ (Gulf of Mexico Region) By Ernest Frederick Sorgnit A Thesis Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial fu]Afillment of the requirements...

Sorgnit, Ernest Frederick

1952-01-01T23:59:59.000Z

358

On the Seasonal Forecasting of Regional Tropical Cyclone Activity  

Science Journals Connector (OSTI)

Tropical cyclones (TCs) are a hazard to life and property and a prominent element of the global climate system; therefore, understanding and predicting TC location, intensity, and frequency is of both societal and scientific significance. ...

G. A. Vecchi; T. Delworth; R. Gudgel; S. Kapnick; A. Rosati; A. T. Wittenberg; F. Zeng; W. Anderson; V. Balaji; K. Dixon; L. Jia; H.-S. Kim; L. Krishnamurthy; R. Msadek; W. F. Stern; S. D. Underwood; G. Villarini; X. Yang; S. Zhang

2014-11-01T23:59:59.000Z

359

Evaluation of Tropical Cyclone Center Identification Methods in Numerical Models  

Science Journals Connector (OSTI)

Identifying the center of a tropical cyclone in a high-resolution model simulation has a number of operational and research applications, including constructing a track, calculating azimuthal means and perturbations, and diagnosing vortex tilt. ...

Leon T. Nguyen; John Molinari; Diana Thomas

2014-11-01T23:59:59.000Z

360

Benefits of Tropical Forest Management Under the New Climate...  

Open Energy Info (EERE)

New Climate Change Agreement-A Case Study in Cambodia Jump to: navigation, search Name Benefits of Tropical Forest Management Under the New Climate Change Agreement-A Case Study in...

Note: This page contains sample records for the topic "tropical convection observed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Southern Hemisphere Additional Ozonesondes (SHADOZ) 19982000 tropical ozone climatology  

E-Print Network (OSTI)

ozone record from Paramaribo, Surinam (6°N, 55°W) (also in SHADOZ) shows a marked contrast to southern tropical ozone because Surinam is often north of the Intertropical Convergence Zone (ITCZ). A more

Thompson, Anne

362

The Political Economy of Deforestation in the Tropics  

E-Print Network (OSTI)

Tropical deforestation accounts for almost one-fifth of greenhouse gas emissions and threatens the world’s most diverse ecosystems. Much of this deforestation is driven by illegal logging. We use novel satellite data that ...

Burgess, Robin

363

Wind Speed Changes of North Atlantic Tropical Cyclones Preceding Landfall  

Science Journals Connector (OSTI)

Landfalling tropical cyclones have been extensively researched, especially their degradation upon coming ashore and the hazardous weather they create along coastlines and farther inland. Many of the factors that weaken storms over land could begin ...

Peter Yaukey

2011-09-01T23:59:59.000Z

364

North Atlantic Tropical Cyclones and U.S. Flooding  

Science Journals Connector (OSTI)

Riverine flooding associated with North Atlantic tropical cyclones (TCs) is responsible for large societal and economic impacts. The effects of TC flooding are not limited to the coastal regions, but affect large areas away from the coast, and often away ...

Gabriele Villarini; Radoslaw Goska; James A. Smith; Gabriel A. Vecchi

2014-09-01T23:59:59.000Z

365

Origin of tropical American burrowing reptiles by transatlantic rafting  

Science Journals Connector (OSTI)

...tropical American burrowing reptiles by transatlantic rafting Nicolas Vidal 1 2 * Anna Azvolinsky...species. Until now, only four or five transatlantic dispersal events were known in terrestrial...amphisbaenid (Kearney 2003), only transatlantic dispersal (Africa to South America...

2008-01-01T23:59:59.000Z

366

Using wind power to prevent tropical cyclone development  

Science Journals Connector (OSTI)

A rough model of a tropical cyclone in the form of a spatial autooscillatory system of the spiral type is proposed. Based on this model, the kinetic energy of a cyclone is estimated and a method of preventing ...

V. I. Kaganov

2006-03-01T23:59:59.000Z

367

Quantifying Environmental Drivers of Future Tropical Forest Extent  

Science Journals Connector (OSTI)

Future changes in atmospheric greenhouse gas concentrations, and their associated influences on climate, will affect the future sustainability of tropical forests. While dynamic global vegetation models (DGVMs) represent the processes by which ...

Peter Good; Chris Jones; Jason Lowe; Richard Betts; Ben Booth; Chris Huntingford

2011-03-01T23:59:59.000Z

368

Pattern formation and dynamics in Rayleigh-Benard convection : numerical simulations of experimentally realistic geometries.  

SciTech Connect

Rayleigh-Benard convection is studied and quantitative comparisons are made, where possible, between theory and experiment by performing numerical simulations of the Boussinesq equations for a variety of experimentally realistic situations. Rectangular and cylindrical geometries of varying aspect ratios for experimental boundary conditions, including fins and spatial ramps in plate separation, are examined with particular attention paid to the role of the mean flow. A small cylindrical convection layer bounded laterally either by a rigid wall, fin, or a ramp is investigated and our results suggest that the mean flow plays an important role in the observed wavenumber. Analytical results are developed quantifying the mean flow sources, generated by amplitude gradients, and its effect on the pattern wavenumber for a large-aspect-ratio cylinder with a ramped boundary. Numerical results are found to agree well with these analytical predictions. We gain further insight into the role of mean flow in pattern dynamics by employing a novel method of quenching the mean flow numerically. Simulations of a spiral defect chaos state where the mean flow is suddenly quenched is found to remove the time dependence, increase the wavenumber and make the pattern more angular in nature.

Paul, M. R.; Chiarn, K.-H.; Cross, M. C.; Fischer, P. F.; Greenside, H. S.; Mathematics and Computer Science; California Inst. of Tech.; Duke University

2003-10-01T23:59:59.000Z

369

Spatio-temporal analysis of Rayleigh-B{acute e}nard convection  

SciTech Connect

The analysis of Rayleigh-B{acute e}nard convection in a thin layer of an incompressible fluid caused by heating from below, is based on the Navier-Stokes equations. In planar geometry the Navier-Stokes equations in Bousinesq-approximation reduce to two nonlinear coupled partial differential equations for the velocity flux function {xi} and the temperature deviation {theta}. These equations are analyzed in form of spatial Fourier modes with time-dependent amplitudes. Only modes corresponding to free-free boundary conditions were selected. In this way, a set of ten coupled nonlinear ordinary differential equations for the mode amplitudes was obtained. These equations were solved numerically for different Rayleigh numbers. The temporal information in the ten dimensional phase space of the mode amplitudes is analyzed with respect to the dimension of the attractor. In addition, a time series of flow patterns in real space is constructed. For this spatio-temporal patterns the empirical orthonormal functions are determined and used to find the temporal evolution from the projection onto the basic vectors. Finally the result of different types of analysis were compared. This should lead to a better understanding how to analyze real systems in terms of observational data, e.g., thermal convection on the surface of the sun. {copyright} {ital 1996 American Institute of Physics.}

Lainscsek, C.S.; Schuerrer, F. [Institut fuer Theoretische Physik, Technische Universitaet Graz, Petersgasse 16, A-8010 Graz, Oesterreich (Austria)

1996-06-01T23:59:59.000Z

370

Stellar Evolution with Enriched Surface Convection Zones I. General Effects of Planet Consumption  

E-Print Network (OSTI)

Abundance analyses of stars with planets have revealed that their metallicities are enhanced relative to field stars. Such a trend was originally suggested to be due to accretion of iron-rich planetary material. Based on this assumption, we have developed a stellar evolution code to model stars with non-uniform metallicity distributions. We have calculated ``polluted'' stellar evolution tracks for stars with M=0.9-1.2 M_sun. Our models encompass a range of initial metal content from Z=0.01 to 0.03, and include metallicity enhancements within the stellar convection zone corresponding to Delta-Z=0.005-0.03. We find that the primary effects of metal enhancement on stellar structure and evolution are expansion of the convection zone and downward shift of effective temperature. In addition, we have computed the surface metallicities expected for stars of different mass for fixed quantities of pollution; there appears to be no correlation with present observational data on the metallicities of stars known to harbor planets.

Ann Marie Cody; Dimitar Sasselov

2004-12-03T23:59:59.000Z

371

Boundary observers for linear and quasi-linear hyperbolic systems with application to flow control  

Science Journals Connector (OSTI)

In this paper we consider the problem of boundary observer design for one-dimensional first order linear and quasi-linear strict hyperbolic systems with n rightward convecting transport PDEs. By means of Lyapunov based techniques, we derive some sufficient ... Keywords: Boundary observers, Hyperbolic systems, Infinite dimensional observer

Felipe Castillo; Emmanuel Witrant; Christophe Prieur; Luc Dugard

2013-11-01T23:59:59.000Z

372

Modeling the Dynamical Coupling of Solar Convection with the Radiative Interior  

Science Journals Connector (OSTI)

The global dynamics of a rotating star like the Sun involves the coupling of a highly turbulent convective envelope overlying a seemingly benign radiative interior. We use the anelastic spherical harmonic code to develop a new class of three-dimensional models that nonlinearly couple the convective envelope to a deep stable radiative interior. The numerical simulation assumes a realistic solar stratification from r = 0.07 up to 0.97R (with R the solar radius), thus encompassing part of the nuclear core up through most of the convection zone. We find that a tachocline naturally establishes itself between the differentially rotating convective envelope and the solid body rotation of the interior, with a slow spreading that is here diffusively controlled. The rapid angular momentum redistribution in the convective envelope leads to a fast equator and slow poles, with a conical differential rotation achieved at mid-latitudes, much as has been deduced by helioseismology. The convective motions are able to overshoot downward about 0.04R into the radiative interior. However, the convective meridional circulation there is confined to a smaller penetration depth and is directed mostly equatorward at the base of the convection zone. Thermal wind balance is established in the lower convection zone and tachocline but departures are evident in the upper convection zone. Internal gravity waves are excited by the convective overshooting, yielding a complex wave field throughout the radiative interior.

Allan Sacha Brun; Mark S. Miesch; Juri Toomre

2011-01-01T23:59:59.000Z

373

Feasibility study for a tropical island sea kayaking ecotourism business  

E-Print Network (OSTI)

of NASTER OF AGRICULTURE August 1993 Najor Subject: Natural Resaurces Development Feasibility Study For 4 Tropical Island Sea Kayak ing Ecotourism Business A Professional Paper by NARY ALEXANDRIA ELDERGILL Appr as to style and content by: Louis A.... Hodges (Chair of Committee) esus H H ojosa (N r) Lauriston E. King mber) Carson E. Watt ( Interim Head of Department) August 1993 ABSTRACT Feasibility Study For A Tropical Island Sea Kayaking Ecotourism Business (May 1992) Mary A. Eldergill, B...

Eldergill, Mary Alexandria

2012-06-07T23:59:59.000Z

374

Scaling Laws for Convection with Temperature-dependent Viscosity and Grain-damage  

E-Print Network (OSTI)

Numerical experiments of convection with grain-damage are used to develop scaling laws for convective heat flow, mantle velocity, and plate velocity across the stagnant lid and plate-tectonic regimes. Three main cases are presented in order of increasing complexity: a simple case wherein viscosity is only dependent on grainsize, a case where viscosity depends on temperature and grainsize, and finally a case where viscosity is temperature and grainsize sensitive, and the grain-growth (or healing) is also temperature sensitive. In all cases, convection with grain-damage scales differently than Newtonian convection due to the effects of grain-damage. For the fully realistic case, numerical results show stagnant lid convection, fully mobilized convection that resembles the temperature-independent viscosity case, and partially mobile or transitional convection, depending on damage to healing ratio, Rayleigh number, and the activation energies for viscosity and healing. Applying our scaling laws for the fully reali...

Foley, Bradford J

2014-01-01T23:59:59.000Z

375

Observations of Stratocumulus Clouds and Their Effect on the Eastern Pacific Surface Heat Budget along 20°S  

E-Print Network (OSTI)

Widespread stratocumulus clouds were observed on nine transects from seven research cruises to the southeastern tropical Pacific Ocean along 20°S, 75°–85°W in October–November of 2001–08. The nine transects sample a unique ...

de Szoeke, Simon P.; Yuter, Sandra; Mechem, David B.; Fairall, Chris W.; Burleyson, Casey D.; Zuidema, Paquita

2012-12-01T23:59:59.000Z

376

Quantifying global marine isoprene fluxes using MODIS chlorophyll observations  

E-Print Network (OSTI)

, with considerable spatial and temporal variability, resulting in a global annual total of 0.1 Tg C/yr. Air vegetation [Guenther et al., 1995], with the tropics responsible for most of the global annual total ($500 TgQuantifying global marine isoprene fluxes using MODIS chlorophyll observations Paul I. Palmer

Palmer, Paul

377

OBSERVATIONS ON THE WEB AND BEHAVIOR OF WENDILGARDA SPIDERS  

E-Print Network (OSTI)

OBSERVATIONS ON THE WEB AND BEHAVIOR OF WENDILGARDA SPIDERS (ARANEAE: THERIDIOSOMATIDAE that theridiosomatids spin modified orb-webs, but only the web of the holarctic Theridiosoma gemmosum (C. L. Koch) has the unusual webs ofsome tropical theridio- somatid spiders that the senior author later identified

Mathis, Wayne N.

378

Response of tropical sea surface temperature, precipitation, and tropical cyclone-related variables to changes in global and local forcing  

E-Print Network (OSTI)

A single-column model is used to estimate the equilibrium response of sea surface temperature (SST), precipitation, and several variables related to tropical cyclone (TC) activity to changes in both local and global forcing. ...

Sobel, Adam

379

Convective cell bands in the central and eastern United States as observed by radar  

E-Print Network (OSTI)

-68, 10 cm, 700 KW, Tinker APSE Oklahoma Data: 27-28 April 1955 Synoptic Situation At 2130C/27, a cold front lay 60 miles northwest of Tinker AFS (Fig. 2). An old prefrontal instability line is shown 100 miles to the southeast Streamline charts...: CFS 6B ~ 10 cm, 700 KM, Tinker AFBg Oklahoma Date: 20 anarch 1955 Synoptic Situation The 1530C surface chez't (Fig. 14) shows a cold front 70 miles northwest of Tinker AFB corresponding to the location of the call bend at this time on the 1530C...

Leach, Wayne

2012-06-07T23:59:59.000Z

380

Aircraft Observations of Sub-cloud Aerosol and Convective Cloud Physical Properties  

E-Print Network (OSTI)

nucleation and Aitken modes. Backtrajectories of Central Mediterranean origin contain a high accumulation mode but low nucleation mode. Eastern Europe backtrajectories have the lowest nucleation mode but exhibit a broad accumulation mode which... are shaped by complex nonlinear processes that are difficult to represent numerically. These processes include nucleation of new particles and evaporation, growth and coagulation of existing particles. Most current models explicitly represent the ASD...

Axisa, Duncan

2011-02-22T23:59:59.000Z

Note: This page contains sample records for the topic "tropical convection observed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Regional variation of convective structure at monsoon onset across South America inferred from TRMM observations.  

E-Print Network (OSTI)

??The variation of precipitation in South America is characterized by different mechanisms that both initiate and sustain precipitation. Analysis to characterize regional differences is done… (more)

Barnhill, Richard

2010-01-01T23:59:59.000Z

382

General Macro-and Microphysical Properties of Deep Convective Clouds as Observed by MODIS  

E-Print Network (OSTI)

(Ramanathan et al. 1989; Harrison et al. 1990; Hartmann et al. 1992) using satellite data have shown that net radiative forcing for DCC systems on large scale is close to zero with large negative shortwave (SW) forcing canceling out large positive longwave (LW) forcing. Kiehl (1994) used a simple calculation to explain

Li, Zhanqing

383

A study of convective precipitation as revealed by radar observation, Texas 1958-59  

E-Print Network (OSTI)

of cca- vective echo selecttce. This selectioa technique docs have a disadvantage ??a( ?, ;, ~i c 7 il. ":f ge. ' "f' . s. . !'i. '. "Ap& ''", " t~W~~ &f41. 'i':0 . . . , , . V. . ': l & '": "' '. . ". r. '4' 5 '. ~i. ' '4' ' ~g M' w'~ g 'FP? VA...~ ~+w'i~4+Vd&&~4j4+'~'A 40k-, 4" ~P" ' rap; ~A" ?~@-;AN, .';". -~g 'MA- 'i"-'m a?-: ~, , (+~?"" ' " '-=:-":. :: - ': . "se~4~5~ fg+Sj Pip. MK~4' '4' ~ ~ '. ' ~$' "4@~~~. ~~. ' ~~'z'. +, ! ~Apl. ''+~~A~%p~~ W ~ t ~'-$~ -~~p...

Clark, Robert Alfred

2012-06-07T23:59:59.000Z

384

Boundary control laws and observer design for convective, turbulent and magnetohydrodynamic flows  

E-Print Network (OSTI)

computer systems, fusion reactors), hypersonic ?ight andcomputer systems, fusion reactors), hypersonic ?ight andcomputer systems, fusion reactors), hyper- sonic ?ight and

Vazquez Valenzuela, Rafael

2006-01-01T23:59:59.000Z

385

ARM - Field Campaign - COPS - Initiation of Convection and the  

NLE Websites -- All DOE Office Websites (Extended Search)

govCampaignsCOPS - Initiation of Convection and the Microphysical govCampaignsCOPS - Initiation of Convection and the Microphysical Properties of Clouds in Orographic Terrain Campaign Links AMF Black Forest Deployment Related Campaigns COPS - AOS Intercomparison 2007.08.09, Jefferson, AMF COPS - ADMIRARI at Black Forest 2007.07.30, Battaglia, AMF COPS - University of Cologne Micromet Station 2007.07.23, Schween, AMF COPS - Cloud Microwave Validation Experiment in Support of CLOWD 2007.06.22, Vogelmann, AMF COPS - WILI Coherent Doppler Wind Lidar at Black Forest 2007.05.10, Althausen, AMF COPS - Multi Wavelength Raman Lidar (MWL) at Black Forest 2007.05.10, Althausen, AMF COPS - 35.5 GHz Cloud Radar Comparison at Black Forest 2007.05.01, Handwerker, AMF COPS - HATPRO at Black Forest 2007.04.01, Crewell, AMF COPS - Micro-Rain Radar at Black Forest

386

Natural convection heating system: off-the-wall evaluation methods  

SciTech Connect

One day data collection results are described for supplementary monitoring of convective air collectors coupled with rock bin storage for house heating. This particular 100% passive heated solar house in the mountains of Arizona had been extensively monitored and previously reported. New information includes the performance of collectors and storage during changeable insolation. In addition, there are evaluations of the alternative techniques for monitoring leakage of dampers on delivery registers, an empirical technique for determining the thermal contribution of direct gain features, and subjective responses of owners to the quality of convective and radiative comfort. Warm is warm, said the owner-builders. Design recommendations for future systems are made and a testing method using a bag volumeter is described. Post-occupancy evaluation is strongly recommended.

Cook, J.; Morris, W.S.

1981-01-01T23:59:59.000Z

387

Bifurcation analysis of interacting stationary modes in thermohaline convection  

SciTech Connect

The Boussinesq equations for thermohaline convection in a finite two-dimensional box and with stress-free boundaries are considered. There are critical values of the aspect ratio at which the conduction state becomes unstable to two different roll patterns simultaneously. Near such a critical value a center manifold reduction allows us to reduce the dynamical behavior of the Boussinesq equations to a standard normal form equation that describes the interaction of two stationary modes. We present explicit analytical expressions for the linear and nonlinear coefficients on which the normal form depends. A numerical investigation of these coefficients leads to a division of the space of parameters (Prandtl number, solute Rayleigh number, Lewis number) into various regions that give rise to qualitatively different bifurcation behavior. Besides those encountered in ordinary convection, a variety of further phenomena is found, in particular in a vicinity of double tricritical points.

Neveling, M.; Dangelmayr, G.

1988-09-01T23:59:59.000Z

388

Using stochastic analysis to capture unstable equilibrium in natural convection  

SciTech Connect

A stabilized stochastic finite element implementation for the natural convection system of equations under Boussinesq assumptions with uncertainty in inputs is considered. The stabilized formulations are derived using the variational multiscale framework assuming a one-step trapezoidal time integration rule. The stabilization parameters are shown to be functions of the time-step size. Provision is made for explicit tracking of the subgrid-scale solution through time. A support-space/stochastic Galerkin approach and the generalized polynomial chaos expansion (GPCE) approach are considered for input-output uncertainty representation. Stochastic versions of standard Rayleigh-Benard convection problems are used to evaluate the approach. It is shown that for simulations around critical points, the GPCE approach fails to capture the highly non-linear input uncertainty propagation whereas the support-space approach gives fairly accurate results. A summary of the results and findings is provided.

Asokan, Badrinarayanan Velamur [Materials Process Design and Control Laboratory, Sibley School of Mechanical and Aerospace Engineering, 188 Frank H.T. Rhodes Hall, Cornell University, Ithaca, NY 14853-3801 (United States); Zabaras, Nicholas [Materials Process Design and Control Laboratory, Sibley School of Mechanical and Aerospace Engineering, 188 Frank H.T. Rhodes Hall, Cornell University, Ithaca, NY 14853-3801 (United States)]. E-mail: zabaras@cornell.edu

2005-09-01T23:59:59.000Z

389

Magnetic particle mixing with magnetic micro-convection for microfluidics  

Science Journals Connector (OSTI)

Abstract In this paper we discuss the magnetic micro-convection phenomenon as a tool for mixing enhancement in microfluidics systems in cases when one of the miscible fluids is a magnetic particle colloid. A system of a water-based magnetic fluid and water is investigated experimentally under homogeneous magnetic field in a Hele–Shaw cell. Subsequent image analysis both qualitatively and quantitatively reveals the high enhancement of mixing efficiency provided by this method. The mixing efficiency dependence on the magnetic field and the physical limits is discussed. A suitable model for a continuous-flow microfluidics setup for mixing with magnetic micro-convection is also proposed and justified with an experiment. In addition, possible applications in improving the speed of ferrohydrodynamic sorting and magnetic label or selected tracer mixing in lab on a chip systems are noted.

Guntars Kitenbergs; Kaspars E¯rglis; Régine Perzynski; Andrejs C?bers

2014-01-01T23:59:59.000Z

390

The CHUVA Project how does convection vary across the Brazil?  

E-Print Network (OSTI)

1 The CHUVA Project ­ how does convection vary across the Brazil? Luiz A. T. Machado1 , Maria A. F de Previsão de Tempo e Estudos Climáticos (CPTEC), Brazil. 2. Universidade de São Paulo. Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Brazil. 3. Departamento de Ciências e Tecnologia Espacial

Chaboureau, Jean-Pierre

391

Non-Boussinesq effects in free thermal convection  

Science Journals Connector (OSTI)

Non-Boussinesq effects in a Rayleigh-Bénard convection system lead to a symmetry breaking between the top and the bottom boundary layers. We have found that the two layers adjust their temperature drops and the thicknesses ? such that their temperature scales ??/g??3 are equal, where ? is the thermal expansion coefficient, g is the gravitational acceleration, and ? and ? are the kinematic viscosity and thermal diffusivity, respectively.

Xiao-Zhong Wu and Albert Libchaber

1991-03-15T23:59:59.000Z

392

On free convection heat transfer with well defined boundary conditions  

SciTech Connect

The scaling of free convection heat transfer is investigated. The non-dimensional groups for Boussinesq and fully compressible variable property free convection, driven by isothermal surfaces, are derived using a previously published novel method of dimensional analysis. Both flows are described by a different set of groups. The applicability of each flow description is experimentally investigated for the case of the isothermal horizontal cylinder in an air-filled isothermal enclosure. The approach taken to the boundary conditions differs from that of previous investigations. Here, it is argued that the best definition of the boundary conditions is achieved for heat exchange between the cylinder and the enclosure rather than the cylinder and an arbitrarily chosen fluid region. The enclosure temperature is shown both analytically and experimentally to affect the Nusselt number. The previously published view that the Boussinesq approximation has only a limited range of application is confirmed, and the groups derived for variable property compressible free convection are demonstrated to be correct experimentally. A new correlation for horizontal cylinder Nusselt number prediction is presented.

Davies, M.R.D.; Newport, D.T.; Dalton, T.M.

1999-07-01T23:59:59.000Z

393

A Comparison of Simulated Cloud Radar Output from the Multiscale Modeling Framework Global Climate Model with CloudSat Cloud Radar Observations  

SciTech Connect

Over the last few years a new type of global climate model (GCM) has emerged in which a cloud-resolving model is embedded into each grid cell of a GCM. This new approach is frequently called a multiscale modeling framework (MMF) or superparameterization. In this article we present a comparison of MMF output with radar observations from the NASA CloudSat mission, which uses a near-nadir-pointing millimeter-wavelength radar to probe the vertical structure of clouds and precipitation. We account for radar detection limits by simulating the 94 GHz radar reflectivity that CloudSat would observe from the high-resolution cloud-resolving model output produced by the MMF. Overall, the MMF does a good job of reproducing the broad pattern of tropical convergence zones, subtropical belts, and midlatitude storm tracks, as well as their changes in position with the annual solar cycle. Nonetheless, the comparison also reveals a number of model shortfalls including (1) excessive hydrometeor coverage at all altitudes over many convectively active regions, (2) a lack of low-level hydrometeors over all subtropical oceanic basins, (3) excessive low-level hydrometeor coverage (principally precipitating hydrometeors) in the midlatitude storm tracks of both hemispheres during the summer season (in each hemisphere), and (4) a thin band of low-level hydrometeors in the Southern Hemisphere of the central (and at times eastern and western) Pacific in the MMF, which is not observed by CloudSat. This band resembles a second much weaker ITCZ but is restricted to low levels.

Marchand, Roger T.; Haynes, J. M.; Mace, Gerald G.; Ackerman, Thomas P.; Stephens, Graeme L.

2009-01-13T23:59:59.000Z

394

CATHARE calculations of Phenix ultimate natural convection test  

SciTech Connect

The Phenix Sodium cooled Fast Reactor (SFR) started operation in 1973 and it was stopped in 2009. Before the reactor was definitively shutdown, in order to collect experimental data for code assessments in the frame of Generation IV an intensive program of ultimate tests was set up. Among these ultimate experiments, two thermal hydraulic tests were performed: an asymmetrical test consisting in a trip on one secondary pump and a natural convection test in the primary circuit. The natural convection test has been used for an international benchmark on system codes in the frame of the IAEA. The CATHARE code - initially developed for water cooled reactors and now extended for safety analyses for other kinds of reactors, including Sodium Fast Reactor - was used by CEA for this benchmark. The paper reminds briefly the Phenix reactor with the main physical parameters and the instrumentation used during the natural convection test. Main test results are also briefly reminded including the evolution of the core and the heat exchangers inlet and outlet temperatures, and some local temperature measurements. The main developments to perform CATHARE SFR computations and the strategy of system code assessment are presented. Then the CATHARE modelling of Phenix reactor is depicted and the various assumptions are pointed out. CATHARE encountered no problem to predict the initial nominal state. Afterwards, the whole transient scenario is calculated and CATHARE calculations are compared to the Phenix measurements. The global trend is rather well predicted by the CATHARE code. Nevertheless, due to complex flow phenomena occurring in large plena and components, the system code encountered physical limitations, leading to remaining discrepancies between code prediction and plant data. Various sensitivity calculations are presented and they bring partial answers. Additional analyses are in progress to understand more deeply the complex 3D phenomena involved during the different phases of the natural convection test. Additional work for coupling CATHARE system code and TRIO-U CFD code is in progress and will bring useful information to better understand the physical phenomena involved during the natural convection test and to improve system modeling for future SFR safety analysis. (authors)

Pialla, D.; Tenchine, D. [CEA, DEN, DM2S/STMF, Grenoble, F-17 rue des Martyrs, 38000 Grenoble (France); Gauthe, P. [CEA, DEN, DER/SESI, Cadarache, F-13108 Saint Paul lez Durance (France); Vasile, A. [CEA, DEN, DER, Cadarache, F-13108 Saint Paul lez Durance (France)

2012-07-01T23:59:59.000Z

395

Survival and activity of Streptococcus faecalis and Escherichia coli in petroleum-contaminated tropical marine waters  

SciTech Connect

The in situ survival and activity of Streptococcus faecalis and Escherichia coli were studied using membrane diffusion chambers in tropical marine waters receiving oil refinery effluents. Protein synthesis, DNA synthesis, respiration or fermentation, INT reduced per cell, and ATP per cell were used to measure physiological activity. Cell densities decreased significantly over time at both sites for both S. faecalis and E. coli; however, no significant differences in survival pattern were observed between S. faecalis and E.coli. Differences in protein synthesis between the two were only observed at a study site which was not heavily oiled. Although fecal streptococci have been suggested as a better indicator of fecal contamination than fecal coliforms in marine waters, in this study both E. coli and S. faecalis survived and remained physiologically active for extended periods of time. These results suggest that the fecal streptococci group is not a better indicator of fecal contamination in tropical marine waters than the fecal coliform group, especially when that environment is high in long-chained hydrocarbons.

Santo Domingo, J.W.; Fuentes, F.A.; Hazen, T.C. [Univ. of Puerto Rico, Rio Piedras (Puerto Rico). Microbial Ecology Lab.

1987-12-31T23:59:59.000Z

396

Tracking Scheme Dependence of Simulated Tropical Cyclone Response to Idealized Climate Simulations  

Science Journals Connector (OSTI)

Future tropical cyclone activity is a topic of great scientific and societal interest. In the absence of a climate theory of tropical cyclogenesis, general circulation models are the primary tool available for investigating the issue. However, the ...

Michael Horn; Kevin Walsh; Ming Zhao; Suzana J. Camargo; Enrico Scoccimarro; Hiroyuki Murakami; Hui Wang; Andrew Ballinger; Arun Kumar; Daniel A. Shaevitz; Jeffrey A. Jonas; Kazuyoshi Oouchi

397

Climate regulation of humid tropical hydrology BHS 10th National Hydrology Symposium, Exeter, 2008  

E-Print Network (OSTI)

might influence tropical water resources. Introduction The humid tropics can be defined as the global, Bangladesh, and most of South-east Asia (Fosberg et al., 1961). Its climate contains distinctive dynamics

Chappell, Nick A

398

The role of gap phase processes in the biomass dynamics of tropical forests  

Science Journals Connector (OSTI)

...gap phase processes in the biomass dynamics of tropical forests...understood. Above-ground woody biomass in some tropical forest...greenhouse gas emissions from biomass burning, decomposition and soils forest in conversion, shifting cultivation and...

2007-01-01T23:59:59.000Z

399

Improved Tropical Cyclone Flight-Level Wind Estimates Using Routine Infrared Satellite Reconnaissance  

Science Journals Connector (OSTI)

A new and improved method to estimate the tropical cyclone flight-level winds using globally and routinely available tropical cyclone (TC) information and infrared (IR) satellite imagery is presented. The developmental data set is comprised of ...

John A. Knaff; Scott P. Longmore; Robert T. DeMaria; Debra A. Molenar

400

The rainfall over tropical South America generated by multiple scale processes.  

E-Print Network (OSTI)

??The rainfall regime over Central America and tropical South America is the most important hydro-meteorological event in the tropics after the Asian-Australian monsoon system. Therefore,… (more)

Carrillo, Carlos Mauricio

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical convection observed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Vertical flux, ecology and dissolution of radiolaria in tropical oceans : implications for the silica cycle  

E-Print Network (OSTI)

Radiolarians which settle through the oceanic water column were recovered from three stations (western Tropical Atlantic-Station E, central Tropical Pacific-P1 and Panama Basin-PB) using PARFLUX sediment traps in moored ...

Takahashi, Kozo

1982-01-01T23:59:59.000Z

402

The tropical precipitation response to Andes topography and ocean heat fluxes in an aquaplanet model  

Science Journals Connector (OSTI)

This aquaplanet modeling study using AM2.1 examines how ocean energy transport and topography influence the location of tropical precipitation. Adding realistic Andes topography regionally displaces tropical rainfall from the equator into the ...

Elizabeth A. Maroon; Dargan M. W. Frierson; David S. Battisti

403

Why do model tropical cyclones intensify more rapidly at low latitudes?  

Science Journals Connector (OSTI)

We examine the problem of why model tropical cyclones intensify more rapidly at low latitudes. Our answer to this question touches on practically all facets of the dynamics and thermodynamics of tropical cyclones. The answer invokes the ...

Roger K. Smith; Gerard Kilroy; Michael T. Montgomery

404

Tropical climate variability from the last glacial maximum to the present  

E-Print Network (OSTI)

This thesis evaluates the nature and magnitude of tropical climate variability from the Last Glacial Maximum to the present. The temporal variability of two specific tropical climate phenomena is examined. The first is the ...

Dahl, Kristina Ariel

2005-01-01T23:59:59.000Z

405

Tropical Pacific nutrient dynamics in the modern and pleistocene ocean : insights from the nitrogen isotope system  

E-Print Network (OSTI)

eastern equatorial Pacific Ocean during the past 3 M.Y. ,in the western tropical Pacific Ocean in the Holocene epoch,eastern tropical North Pacific Ocean, Mar. Chem. , 3, 271–

Rafter, Patrick Anthony

2009-01-01T23:59:59.000Z

406

Barotropic Rossby Waves Radiating from Tropical Instability Waves in the Pacific Ocean  

Science Journals Connector (OSTI)

Tropical instability waves are triggered by instabilities of the equatorial current systems, and their sea level signal, with peak amplitude near 5°N, is one of the most prominent features of the dynamic topography of the tropics. Cross-spectral ...

J. Thomas Farrar

2011-06-01T23:59:59.000Z

407

The role of piscivores in a species-rich tropical river  

E-Print Network (OSTI)

Much of the world's species diversity is located in tropical and sub-tropical ecosystems, and a better understanding of the ecology of these systems is necessary to stem biodiversity loss and assess community- and ecosystem-level responses...

Layman, Craig Anthony

2004-11-15T23:59:59.000Z

408

Probability Distributions and Threshold Selection for Monte Carlo–Type Tropical Cyclone Wind Speed Forecasts  

Science Journals Connector (OSTI)

Probabilistic wind speed forecasts for tropical cyclones from Monte Carlo–type simulations are assessed within a theoretical framework for a simple unbiased Gaussian system that is based on feature size and location error that mimic tropical ...

Michael E. Splitt; Steven M. Lazarus; Sarah Collins; Denis N. Botambekov; William P. Roeder

2014-10-01T23:59:59.000Z

409

Comparisons of Two- and Three-Dimensional Convection in Type I X-ray Bursts  

E-Print Network (OSTI)

We perform the first detailed three-dimensional simulation of low Mach number convection preceding thermonuclear ignition in a mixed H/He X-ray burst. Our simulations include a moderate-sized, approximate network that captures hydrogen and helium burning up through rp-process breakout. We look in detail at the difference between two- and three-dimensional convective fields, including the details of the turbulent convection.

Zingale, M; Nonaka, A; Almgren, A S; Bell, J B

2014-01-01T23:59:59.000Z

410

A Multicase Comparative Assessment of the Ensemble Kalman Filter for Assimilation of Radar Observations. Part II: Short-Range Ensemble Forecasts  

Science Journals Connector (OSTI)

The quality of convective-scale ensemble forecasts, initialized from analysis ensembles obtained through the assimilation of radar observations using an ensemble Kalman filter (EnKF), is investigated for cases whose behaviors span supercellular, ...

Altu? Aksoy; David C. Dowell; Chris Snyder

2010-04-01T23:59:59.000Z

411

GEOGRAPHICAL DISRIBUTION OF WOODY BIOMASS CARBON IN TROPICAL AFRICA: AN  

NLE Websites -- All DOE Office Websites (Extended Search)

Geographical Distribution of Woody Biomass Carbon in Tropical Africa: An Geographical Distribution of Woody Biomass Carbon in Tropical Africa: An Updated Database for 2000, NDP-055b TABLES Please cite as: Gibbs, H.K. and S. Brown. 2007. Geographical Distribution of Woody Biomass Carbon in Tropical Africa: An Updated Database for 2000, NDP-055b. Available at [http://cdiac.ornl.gov/epubs/ndp/ndp055/ndp055b.html] from the Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee, U.S.A. Tables 1-4 Files in this numeric data package Variable formats of af_biomass.vat Variable formats of af_carbon.vat Variable formats of glc_subset_af.vat Variable formats of land_geo.vat Variable formats of pb_geo.vat Table 1. Files in this numeric data package File No. File name File size (bytes) File description

412

Damping of Type I X-ray Burst Oscillations by Convection  

E-Print Network (OSTI)

I construct a simple model of the convective burning layer during a type I X-ray burst to investigate the effects convection has on the stability of the layer to nonradial oscillations. A linear perturbation analysis demonstrates that the region is stable to nonradial oscillations when energy transport is convection-dominated, but it is unstable when energy transport is radiation-dominated. Thus, efficient convection always dampens oscillations. These results may explain the nondetection of oscillations during the peak of some X-ray bursts.

Randall L. Cooper

2008-03-26T23:59:59.000Z

413

Convection in X-ray Bursts Michael Zingale Stony Brook University  

NLE Websites -- All DOE Office Websites (Extended Search)

many stellar systems dominated by convective transport of energy - Supernovae (both thermonuclear and gravitational) - X-ray bursts and novae (thermonuclear explosion of accreted...

414

Tropical forest responses to increasing atmospheric CO2: current knowledge and opportunities for future research  

E-Print Network (OSTI)

their representation in Earth system models. Tropical forests play a significant role in the global carbon cycle

Bermingham, Eldredge

415

The divergent wind component in data sparse tropical wind fields  

E-Print Network (OSTI)

THE DIVERGENT WIND COMPONENT IN DATA SPARSE TROPICAL WIND FIELDS A Thesis by BRUCE ALAN SNYDER Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE December... 1985 Major Subject: Meteorology THE DIVERGENT WIND COMPONENT IN DATA SPARSE TROPICAL WIND FIELDS A Thesis by BRUCE ALAN SNYDER Approved as to style and content by: James P. McGuirk (Co-Chairman) Aylmer IL Thompson (Co-Chairman) W. Homer...

Snyder, Bruce Alan

1985-01-01T23:59:59.000Z

416

Global warming shifts Pacific tropical cyclone location MinHo Kwon,1,3  

E-Print Network (OSTI)

Global warming shifts Pacific tropical cyclone location Tim Li,1 MinHo Kwon,1,3 Ming Zhao,3 Jong) is used to investigate the change of tropical cyclone frequency in the North Pacific under global warming, and W. Yu (2010), Global warming shifts Pacific tropical cyclone location, Geophys. Res. Lett., 37, L

Li, Tim

417

Tree planting by small producers in the tropics: A comparative study of Brazil and Panama  

E-Print Network (OSTI)

Tree planting by small producers in the tropics: A comparative study of Brazil and Panama Cynthia S in revised form 25 March 2002 Key words: Brazil, Land tenure, Panama, Reforestation, Small farmers, Tropical in the tropical frontier regions of Panama and Brazil in order to gauge the magnitude of reforestation activities

Simmons, Cynthia S.

418

Interhemispheric Teleconnections from Tropical Heat Sources in Intermediate and Simple Models  

E-Print Network (OSTI)

the prescribed tropical heating in both intensity and geographical extent and by inducing remote precipitation anomalies by interaction with the basic state. 1. Introduction Tropical heat sources can remotely influenceInterhemispheric Teleconnections from Tropical Heat Sources in Intermediate and Simple Models XUAN

419

An optimizing reduced order FDS for the tropical Pacific Ocean reduced gravity model  

E-Print Network (OSTI)

An optimizing reduced order FDS for the tropical Pacific Ocean reduced gravity model Zhendong Luoa) for the tropical Pacific Ocean reduced gravity model. Ensembles of data are compiled from transient solutions computed from the discrete equation system derived by FDS for the tropical Pacific Ocean reduced gravity

Aluffi, Paolo

420

Eddy mean flow decomposition and eddy diffusivity estimates in the tropical Pacific Ocean  

E-Print Network (OSTI)

Eddy mean flow decomposition and eddy diffusivity estimates in the tropical Pacific Ocean: 2] Eddy diffusivity of the surface velocity field in the tropical Pacific Ocean was estimated using diffusivity estimates in the tropical Pacific Ocean: 2. Results, J. Geophys. Res., 107(C10), 3154, doi:10

Note: This page contains sample records for the topic "tropical convection observed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Reduced Order Modeling of the Upper Tropical Pacific Ocean Model Using Proper Orthogonal Decomposition  

E-Print Network (OSTI)

Reduced Order Modeling of the Upper Tropical Pacific Ocean Model Using Proper Orthogonal of a large-scale upper ocean circulation in the tropic Pacific domain. We construct different POD models-scale seasonal variability of the tropic Pacific obtained by the original model is well captured by a low

Aluffi, Paolo

422

Validating Atmospheric Reanalysis Data Using Tropical Cyclones as Thermometers James P. Kossin  

E-Print Network (OSTI)

1 Validating Atmospheric Reanalysis Data Using Tropical Cyclones as Thermometers James P. Kossin tropical cyclones as thermometers. Bull. Amer. Meteor. Soc. doi:10.1175/BAMS-D-14-00180, in press. Capsule Tropical cyclones are used as traveling thermometers to globally sample upper-tropospheric temperatures

Kossin, James P.

423

ARM - Lesson Plans: Tropical Western Pacific  

NLE Websites -- All DOE Office Websites (Extended Search)

of Gases Microclimate Moving Water and Waves Observing Wind Speed and Cloudiness Ocean Currents Outgassing Past Sea Level Data Plant Growth and Carbon Dioxide Planting...

424

Macroscopic observables  

SciTech Connect

We study macroscopic observables defined as the total value of a physical quantity over a collection of quantum systems. We show that previous results obtained for an infinite ensemble of identically prepared systems lead to incorrect conclusions for finite ensembles. In particular, exact measurement of a macroscopic observable significantly disturbs the state of any finite ensemble. However, we show how this disturbance can be made arbitrarily small when the measurements are of finite accuracy. We demonstrate a general trade-off between state disturbance and measurement coarseness as a function of the size of the ensemble. Using this trade-off, we show that the histories generated by any sequence of finite accuracy macroscopic measurements always generate a consistent family in the absence of large-scale entanglement for sufficiently large ensembles. Hence, macroscopic observables behave 'classically' provided that their accuracy is coarser than the quantum correlation length scale of the system. The role of these observable is also discussed in the context of NMR quantum information processing and bulk ensemble quantum state tomography.

Poulin, David [Perimeter Institute for Theoretical Physics, Waterloo, Ontario, N2L 2Y5 (Canada); Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Department of Physics, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

2005-02-01T23:59:59.000Z

425

Macroscopic observables  

Science Journals Connector (OSTI)

We study macroscopic observables defined as the total value of a physical quantity over a collection of quantum systems. We show that previous results obtained for an infinite ensemble of identically prepared systems lead to incorrect conclusions for finite ensembles. In particular, exact measurement of a macroscopic observable significantly disturbs the state of any finite ensemble. However, we show how this disturbance can be made arbitrarily small when the measurements are of finite accuracy. We demonstrate a general trade-off between state disturbance and measurement coarseness as a function of the size of the ensemble. Using this trade-off, we show that the histories generated by any sequence of finite accuracy macroscopic measurements always generate a consistent family in the absence of large-scale entanglement for sufficiently large ensembles. Hence, macroscopic observables behave “classically” provided that their accuracy is coarser than the quantum correlation length scale of the system. The role of these observable is also discussed in the context of NMR quantum information processing and bulk ensemble quantum state tomography.

David Poulin

2005-02-07T23:59:59.000Z

426

Natural convection in high heat flux tanks at the Hanford Waste Site / [by] Mark van der Helm and Mujid S. Kazimi  

E-Print Network (OSTI)

A study was carried out on the potential for natural convection and the effect of natural convection in a High Heat Flux Tank, Tank 241-C-106, at the Hanford Reservation. To determine the existence of natural convection, ...

Van der Helm, Mark Johan, 1972-

1996-01-01T23:59:59.000Z

427

Convection in magnetic fluids with internal heat generation  

SciTech Connect

The effect of a uniform distribution of heat source on the onset of stationary convection in a horizontal Boussinesq magnetic fluid layer bounded by isothermal nonmagnetic boundary is investigated. Solutions are obtained using a higher order Galerkin expansion technique, considering different isothermal boundary combinations (rigid-rigid, rigid-free, and free-free). It is found that the effect of internal magnetic number, due to a heat source, is to make the system more unstable. The results obtained, in the limiting cases, compare well with the existing literature.

Rudraiah, N.; Sekhar, G.N. (Bangalore Univ. (India))

1991-02-01T23:59:59.000Z

428

Defect Chaos of Oscillating Hexagons in Rotating Convection  

SciTech Connect

Using coupled Ginzburg-Landau equations, the dynamics of hexagonal patterns with broken chiral symmetry are investigated, as they appear in rotating non-Boussinesq or surface-tension-driven convection. We find that close to the secondary Hopf bifurcation to oscillating hexagons the dynamics are well described by a single complex Ginzburg-Landau equation (CGLE) coupled to the phases of the hexagonal pattern. At the band center these equations reduce to the usual CGLE and the system exhibits defect chaos. Away from the band center a transition to a frozen vortex state is found. (c) 2000 The American Physical Society.

Echebarria, Blas; Riecke, Hermann

2000-05-22T23:59:59.000Z

429

Granular fountains: Convection cascade in a compartmentalized granular gas  

Science Journals Connector (OSTI)

This paper extends the two-compartment granular fountain [D. van der Meer, P. Reimann, K. van der Weele, and D. Lohse, Phys. Rev. Lett. 92, 184301 (2004)] to an arbitrary number of compartments: The tendency of a granular gas to form clusters is exploited to generate spontaneous convective currents, with particles going down in the well-filled compartments and going up in the diluted ones. We focus upon the bifurcation diagram of the general K-compartment system, which is constructed using a dynamical flux model and which proves to agree quantitatively with results from molecular dynamics simulations.

Devaraj van der Meer; Ko van der Weele; Peter Reimann

2006-06-22T23:59:59.000Z

430

Generation of large-scale winds in horizontally anisotropic convection  

E-Print Network (OSTI)

We simulate three-dimensional, horizontally periodic Rayleigh-B\\'enard convection between free-slip horizontal plates, rotating about a horizontal axis. When both the temperature difference between the plates and the rotation rate are sufficiently large, a strong horizontal wind is generated that is perpendicular to both the rotation vector and the gravity vector. The wind is turbulent, large-scale, and vertically sheared. Horizontal anisotropy, engendered here by rotation, appears necessary for such wind generation. Most of the kinetic energy of the flow resides in the wind, and the vertical turbulent heat flux is much lower on average than when there is no wind.

von Hardenberg, J; Provenzale, A; Spiegel, E A

2015-01-01T23:59:59.000Z

431

Barometric pressure variations associated with eastern Pacific tropical instability waves  

E-Print Network (OSTI)

with the life cycle of deep convective mixing, i.e., 8-12 hours (Bretherton et al. 1995). Likewise, sounding, USA. E-mail: cronin@pmel.noaa.gov. #12;2 Abstract. Barometric pressure, surface temperature and wind difference also had a spectral peak in the 20-30 day TIW band. Cross- spectral analysis shows that within

Xie, Shang-Ping

432

Detection of iodine monoxide in the tropical free troposphere  

Science Journals Connector (OSTI)

...runs were conducted with WRF (22): (i) a 60-h...km) to better resolve local deep convection. The model...retrieval. Fig. S3. WRF simulations from a cloud-resolving...line. Scattered trade wind cumulus clouds (gray...research and forecast model (WRF) analysis of air...

Barbara Dix; Sunil Baidar; James F. Bresch; Samuel R. Hall; K. Sebastian Schmidt; Siyuan Wang; Rainer Volkamer

2013-01-01T23:59:59.000Z

433

Inverse cascade and symmetry breaking in rapidly-rotating Boussinesq convection  

E-Print Network (OSTI)

In this paper we present numerical simulations of rapidly-rotating Rayleigh-B\\'enard convection in the Boussinesq approximation with stress-free boundary conditions. At moderately low Rossby number and large Rayleigh number, we show that a large-scale depth-invariant flow is formed, reminiscent of the condensate state observed in two-dimensional flows. We show that the large-scale circulation shares many similarities with the so-called vortex, or slow-mode, of forced rotating turbulence. Our investigations show that at a fixed rotation rate the large-scale vortex is only observed for a finite range of Rayleigh numbers, as the quasi-two-dimensional nature of the flow disappears at very high Rayleigh numbers. We observe slow vortex merging events and find a non-local inverse cascade of energy in addition to the regular direct cascade associated with fast small-scale turbulent motions. Finally, we show that cyclonic structures are dominant in the small-scale turbulent flow and this symmetry breaking persists in ...

Favier, B; Proctor, M R E

2014-01-01T23:59:59.000Z

434

Rayleigh-Benard convection with a radial ramp in plate separation.  

SciTech Connect

Pattern formation in Rayleigh-Benard convection in a large-aspect-ratio cylinder with a radial ramp in the plate separation is studied analytically and numerically by performing numerical simulations of the Boussinesq equations. A horizontal mean flow and a vertical large scale counterflow are quantified and used to understand the pattern wavenumber. Our results suggest that the mean flow, generated by amplitude gradients, plays an important role in the roll compression observed as the control parameter is increased. Near threshold the mean flow has a quadrupole dependence with a single vortex in each quadrant while away from threshold the mean flow exhibits an octupole dependence with a counter-rotating pair of vortices in each quadrant. This is confirmed analytically using the amplitude equation and Cross-Newell mean flow equation. By performing numerical experiments the large scale counterflow is also found to aid in the roll compression away from threshold but to a much lesser degree. Our results yield an understanding of the pattern wavenumbers observed in experiment away from threshold and suggest that near threshold the mean flow and large scale counterflow are not responsible for the observed shift to smaller than critical wavenumbers.

Paul, M. R.; Cross, M. C.; Fischer, P. F.; Mathematics and Computer Science; California Inst. of Tech.

2002-10-01T23:59:59.000Z

435

Hybrid coupled models of the tropical Pacific: I interannual variability  

E-Print Network (OSTI)

Y. Tang Hybrid coupled models of the tropical Pacific: I interannual variability Received: 20 Two hybrid coupled models (HCMs), an intermediate complexity dynamical ocean model cou- pled to either), hybrid models (e.g., Barnett et al. 1993; Balmaseda et al. 1994,1995), and fully coupled general

Tang, Youmin

436

High-Frequency Skywave Radar Track of Tropical Storm Debra  

Science Journals Connector (OSTI)

Tropical Storm Debra was tracked over a 31 h period in the Gulf of Mexico using the Wide Aperture Research Facility (WARF) high-frequency (HF) skywave radar in California. In contrast to the first WARF skywave radar tracking experiment in which ...

Joseph W. Maresca Jr.; Christopher T. Carlson

1981-04-01T23:59:59.000Z

437

A QuikSCAT climatology of tropical cyclone size  

E-Print Network (OSTI)

QuikSCAT data of near-surface wind vectors for the years 1999–2008 are used to create a climatology of tropical cyclone (TC) size, defined as the radius of vanishing winds. The azimuthally-averaged radius of 12 ms?1 [ms ...

Chavas, Daniel Robert

438

Marketing of Tropical Hardwood Wood Products from Ghana  

E-Print Network (OSTI)

Marketing of Tropical Hardwood Wood Products from Ghana: An Exploratory Study Kofi Poku Richard Vlosky Forest Products Marketing Program Louisiana Forest Products Laboratory Louisiana State University Agricultural Center #12;Overview · Background - the forest of Ghana · Current forest industry and market

439

Association for Tropical Biology and Conservation Brownsberg Declaration 2008  

E-Print Network (OSTI)

Paramaribo, Suriname VERKLARING INZAKE HET TOEKENNEN VAN PERMANENT BESCHERMDE STATUS AAN DE BROWNSBERG EN DE. IN OVERWEGING NEMENDE DAT de bauxiethoudende Bergen in noordoost- Suriname ­ Brownsberg, Nassau en Lely ­ deelAssociation for Tropical Biology and Conservation Brownsberg Declaration 2008 13 June 2008

Norconk, Marilyn A.

440

Tropical Timber Market Report Volume 15 Number 3, 1 15  

E-Print Network (OSTI)

Freight Index 20 Tropical Timber Price Trends 20 Top Story Clarification on Gabon log ban At a recent meeting with Gabon's Minister for Forests, executives of the country's timber industries were advised Clarification on Gabon log ban 2 Malaysia progresses with VPA 3 Plywood push in India 5 Call for lower import

Note: This page contains sample records for the topic "tropical convection observed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

TROPIC: Transactional Resource Orchestration Platform In the Cloud  

E-Print Network (OSTI)

TROPIC: Transactional Resource Orchestration Platform In the Cloud Changbin Liu, Yun Mao*, Xu Chen ­ InfrastructureasaService (IaaS) Cloud · Provide cloud infrastructure services: virtual machines (VMs), virtual block devices, VPNs · Widely adopted, e.g. Amazon Elastic Compute Cloud (EC2) ­ Cloud resource

Plotkin, Joshua B.

442

Detection of iodine monoxide in the tropical free troposphere  

E-Print Network (OSTI)

19, 2012) Atmospheric iodine monoxide (IO) is a radical that catalytically destroys heat trapping in the remote tropical marine boundary layer (MBL) (2­4). IO further affects the oxidative capacity iodine species over the remote ocean remain poorly understood (11, 14) but are currently thought

443

Arbuscular mycorrhizal mycelial respiration in a moist tropical forest  

E-Print Network (OSTI)

Universiteit, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands; 4 Ecological Farming Systems, Research Tropical Research Institute, 0843- 03092 Balboa, Ancon, Panama; 3 Institute of Ecological Science, Vrije Station ART, Swiss Federal Research Institute Agroscope, Zurich, Switzerland; 5 Plant­Microbe Interactions

Bermingham, Eldredge

444

Future economic damage from tropical cyclones: sensitivities to societal and  

E-Print Network (OSTI)

in support of advocacy to reduce greenhouse gas emissions. For instance, in his movie An inconvenient truth related to tropical cyclones than efforts to modulate the behaviour of storms through greenhouse gas emissions reduction policies, typically called climate mitigation and achieved through energy policies

Colorado at Boulder, University of

445

Drivers of phytoplankton, bacterioplankton, and zooplankton carbon biomass in tropical hydroelectric reservoirs  

Science Journals Connector (OSTI)

Abstract Studies of carbon sources in plankton communities are important because carbon content has become the main currency used in functional studies of aquatic ecosystems. We evaluated the contribution to the total organic carbon pool from different plankton communities (phytoplankton, bacterioplankton, and zooplankton – C-biota) and its drivers in eight tropical hydroelectric reservoirs with different trophic and hydrological status and different physical features. Our systems were separated into three groups based on trophic status and water residence time: (i) mesotrophic with low residence time (ML); (ii) mesotrophic with high residence time (MH); and (iii) eutrophic with low residence time (EL). Our hypothesis that reservoirs with low water residence times and low nutrient concentrations would show the lowest C-biota was supported. Phytoplankton carbon (C-phy) showed the highest concentrations in the EL, followed by MH and ML systems. The EL group also showed significantly higher zooplankton carbon (C-zoo). No significant difference was observed for bacteria carbon (C-bac) among the three system groups. In addition to trophic status and water residence time, regression analyses revealed that water temperature, light, pH, and dissolved organic carbon concentrations were the main drivers of plankton communities in these large tropical hydroelectric reservoirs.

Lúcia H.S. Silva; Vera L.M. Huszar; Marcelo M. Marinho; Luciana M. Rangel; Jandeson Brasil; Carolina D. Domingues; Christina C. Branco; Fábio Roland

2014-01-01T23:59:59.000Z

446

Variational bounds on energy dissipation in incompressible flows. III. Convection  

SciTech Connect

Building on a method of analysis for the Navier-Stokes equations introduced by Hopf [Math. Ann. {bold 117}, 764 (1941)], a variational principle for upper bounds on the largest possible time averaged convective heat flux is derived from the Boussinesq equations of motion. When supplied with appropriate test background fields satisfying a spectral constraint, reminiscent of an energy stability condition, the variational formulation produces rigorous upper bounds on the Nusselt number (Nu) as a function of the Rayleigh number (Ra). For the case of vertical heat convection between parallel plates in the absence of sidewalls, a simplified (but rigorous) formulation of the optimization problem yields the large Rayleigh number bound Nu{le}0.167 Ra{sup 1/2}{minus}1. Nonlinear Euler-Lagrange equations for the optimal background fields are also derived, which allow us to make contact with the upper bound theory of Howard [J. Fluid Mech. {bold 17}, 405 (1963)] for statistically stationary flows. The structure of solutions of the Euler-Lagrange equations are elucidated from the geometry of the variational constraints, which sheds light on Busse{close_quote}s [J. Fluid Mech. {bold 37}, 457 (1969)] asymptotic analysis of general solutions to Howard{close_quote}s Euler-Lagrange equations. The results of our analysis are discussed in the context of theory, recent experiments, and direct numerical simulations. {copyright} {ital 1996 The American Physical Society.}

Doering, C.R. [Center for Nonlinear Studies, MS-B258, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Center for Nonlinear Studies, MS-B258, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Constantin, P. [Department of Mathematics, University of Chicago, Chicago, Illinois 60637 (United States)] [Department of Mathematics, University of Chicago, Chicago, Illinois 60637 (United States)

1996-06-01T23:59:59.000Z

447

Non-Boussinesq Rolls in 2d Thermal Convection  

E-Print Network (OSTI)

A study of convection in a circular two dimensional cell is presented. The system is heated and cooled at two diametrically opposed points on the edge of the circle, which are parallel or anti-parallel to gravity. The latter's role in the plane of the cell can be changed by tilting the cell. When the system is in a horizontal position, a non-trivial analytic solution for the temperature distribution of the quiescent fluid can be found. For a slight inclination, the projection of gravity in the plane of the cell is used as a perturbation parameter in the full hydrodynamic description, as the Boussinesq approximation is inadequate. To first order, the equations are solved for the stationary case and four symmetrical rolls become apparent, showing that a purely conductive state is impossible if gravity -however small- is present; an approximate closed analytical expression is obtained, which describes the four convection rolls. Further analysis is done by a direct numerical integration. Comparison with prelimina...

Málaga, C; Peralta-Fabi, R; Arzate, C

2013-01-01T23:59:59.000Z

448

Special session: computational predictability of natural convection flows in enclosures  

SciTech Connect

Modern thermal design practices often rely on a ''predictive'' simulation capability--although predictability is rarely quantified and often difficult to confidently achieve in practice. The computational predictability of natural convection in enclosures is a significant issue for many industrial thermal design problems. One example of this is the design for mitigation of optical distortion due to buoyancy-driven flow in large-scale laser systems. In many instances the sensitivity of buoyancy-driven enclosure flows can be linked to the presence of multiple bifurcation points that yield laminar thermal convective processes that transition from steady to various modes of unsteady flow. This behavior is brought to light by a problem as ''simple'' as a differentially-heated tall rectangular cavity (8:1 height/width aspect ratio) filled with a Boussinesq fluid with Pr = 0.71--which defines, at least partially, the focus of this special session. For our purposes, the differentially-heated cavity provides a virtual fluid dynamics laboratory.

Christon, M A; Gresho, P M; Sutton, S B

2000-08-14T23:59:59.000Z

449

ARM - Midlatitude Continental Convective Clouds (jensen-sonde)  

SciTech Connect

A major component of the Mid-latitude Continental Convective Clouds Experiment (MC3E) field campaign was the deployment of an enhanced radiosonde array designed to capture the vertical profile of atmospheric state variables (pressure, temperature, humidity wind speed and wind direction) for the purpose of deriving the large-scale forcing for use in modeling studies. The radiosonde array included six sites (enhanced Central Facility [CF-1] plus five new sites) launching radiosondes at 3-6 hour sampling intervals. The network will cover an area of approximately (300)2 km2 with five outer sounding launch sites and one central launch location. The five outer sounding launch sites are: S01 Pratt, KS [ 37.7oN, 98.75oW]; S02 Chanute, KS [37.674, 95.488]; S03 Vici, Oklahoma [36.071, -99.204]; S04 Morris, Oklahoma [35.687, -95.856]; and S05 Purcell, Oklahoma [34.985, -97.522]. Soundings from the SGP Central Facility during MC3E can be retrieved from the regular ARM archive. During routine MC3E operations 4 radiosondes were launched from each of these sites (approx. 0130, 0730, 1330 and 1930 UTC). On days that were forecast to be convective up to four additional launches were launched at each site (approx. 0430, 1030, 1630, 2230 UTC). There were a total of approximately 14 of these high frequency launch days over the course of the experiment.

Jensen, Mike; Comstock, Jennifer; Genio, Anthony Del; Giangrande, Scott; Kollias, Pavlos

2012-01-19T23:59:59.000Z

450

Neutrino-driven convection versus advection in core collapse supernovae  

E-Print Network (OSTI)

A toy model is analyzed in order to evaluate the linear stability of the gain region immediately behind a stalled accretion shock, after core bounce. This model demonstrates that a negative entropy gradient is not sufficient to warrant linear instability. The stability criterion is governed by the ratio \\chi of the advection time through the gain region divided by the local timescale of buoyancy. The gain region is linearly stable if \\chi3, perturbations are unstable in a limited range of horizontal wavelengths centered around twice the vertical size H of the gain region. The threshold horizontal wavenumbers k_{min} and k_{max} follow simple scaling laws such that Hk_{min}\\propto 1/{\\chi} and Hk_{max}\\propto \\chi. The convective stability of the l=1 mode in spherical accretion is discussed, in relation with the asymmetric explosion of core collapse supernovae. The advective stabilization of long wavelength perturbations weakens the possible influence of convection alone on a global l=1 mode.

T. Foglizzo; L. Scheck; H. -Th. Janka

2005-07-27T23:59:59.000Z

451

Pattern formation in binary mixture convection in cylindrical three-dimensional cells  

E-Print Network (OSTI)

present numerical results of pattern selection near the onset of convection for a water-ethanol mixture of the cell is = 11. The onset of convection occurs via a subcritical Hopf bifurcation. Slightly above ratio mixtures, S subcritical and gives rise

Batiste, Oriol

452

Lattice Boltzmann model for melting with natural convection Christian Huber a,*, Andrea Parmigiani b  

E-Print Network (OSTI)

Lattice Boltzmann model for melting with natural convection Christian Huber a,*, Andrea Parmigiani Boltzmann Heat transfer Melting Convection a b s t r a c t We develop a lattice Boltzmann method to couple and Stefan numbers) over which the correlations have been tested remains limited. The lattice Boltzmann

Manga, Michael

453

A LATTICE BOLTZMANN MODEL FOR CONVECTION HEAT TRANSFER IN POROUS MEDIA  

E-Print Network (OSTI)

A LATTICE BOLTZMANN MODEL FOR CONVECTION HEAT TRANSFER IN POROUS MEDIA Zhaoli Guo and T. S. Zhao Kong, China A lattice Boltzmann model for convection heat transfer in porous media is proposed-difference, finite-volume, and finite-element methods (e.g., [2, 3]). The lattice Boltzmann method (LBM

Zhao, Tianshou

454

Review of fluid flow and convective heat transfer within rotating disk cavities  

E-Print Network (OSTI)

1 Review of fluid flow and convective heat transfer within rotating disk cavities with impinging axial direction #12;5 Introduction Fluid flow and convective heat transfer in rotor-stator configuration heat transfer in rotor-stator configurations, which are of great importance in different engineering

Paris-Sud XI, Université de

455

Numerical study of natural convection in a vertical porous annulus with discrete heating  

E-Print Network (OSTI)

Numerical study of natural convection in a vertical porous annulus with discrete heating M. Sankar online 20 December 2010 Keywords: Natural convection Annulus Discrete heating Porous medium Radii ratio to discrete heating. The outer wall is maintained iso- thermally at a lower temperature, while the top

Lopez, John M.

456

Benchmark solution for a three-dimensional mixed convection flow -Detailed technical report  

E-Print Network (OSTI)

in many industrial applications: thermal and chemical reactors, chimneys, solar collectors, thermal-dimensional mixed convection flow in a horizontal rectangular channel heated from below and cooled from above) configuration (i.e. mixed convection flows in horizontal rectan- gular channels heated from below

Boyer, Edmond

457

THE EFFECT OF A SHEAR FLOW ON CONVECTION NEAR A TWO-DIMENSIONAL HOT-PATCH  

Science Journals Connector (OSTI)

......CONVECTION NEAR A TWO-DIMENSIONAL HOT-PATCH I. C. WALTON Department of Mathematics...takes the form of a two-dimensional hot-patch. Ingersoll's (6) results for uniform...CONVECTION NEAR A TWO-DIMENSIONAL HOT-PATCH By I. C. WALTON (Department of Mathematics......

I. C. WALTON

1985-11-01T23:59:59.000Z

458

THE MAGNETIC CONNECTION BETWEEN THE CONVECTION ZONE AND CORONA IN THE QUIET SUN  

E-Print Network (OSTI)

THE MAGNETIC CONNECTION BETWEEN THE CONVECTION ZONE AND CORONA IN THE QUIET SUN W. P. Abbett Space connection between the convectively unstable layers below the visible surface of the Sun and the overlying application of this numerical model, we present a series of simulations of the quiet Sun in a domain

Abbett, Bill

459

The evolution of total lightning and radar reflectivity characteristics of two mesoscale convective systems over Houston, Texas  

E-Print Network (OSTI)

Two mesoscale convective systems (MCSs) passed over the Houston Lightning Detection and Ranging (LDAR) network on 31 October 2005 and 21 April 2006. As the MCSs traverse the LDAR network, the systems slowly mature with a weakening convective line...

Hodapp, Charles Lee

2009-05-15T23:59:59.000Z

460

Evaluation of Ensemble Configurations for the Analysis and Prediction of Heavy-Rain-Producing Mesoscale Convective Systems  

Science Journals Connector (OSTI)

This study investigates probabilistic forecasts made using different convection-allowing ensemble configurations for a three-day period in June 2010 when numerous heavy-rain-producing mesoscale convective systems (MCSs) occurred in the United ...

Russ S. Schumacher; Adam J. Clark

2014-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical convection observed" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

TRACKING TROPICAL CLOUD SYSTEMS -OBSERVATIONS FOR THE DIAGNOSIS OF SIMULATIONS BY THE WEATHER RESEARCH  

E-Print Network (OSTI)

using a satellite cloud tracking algorithm (Boer and Ramanathan, 1997), and the statistics are compared with the U.S. Department of Energy. The publisher by accepting the manuscript for publication acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish

462

Sources of atmospheric mercury in the tropics: continuous observations at a coastal site in Suriname  

E-Print Network (OSTI)

to mercury pollution in Suriname” including oxidation byat a coastal site in Suriname 1 , D. Wip 2 , T. Warneke 1 ,de Kom Universiteit van Suriname, Paramaribo, Suriname 3

Muller, D.; Wip, D.; Warneke, T.; Holmes, C. D; Dastoor, A.; Notholt, J.

2012-01-01T23:59:59.000Z

463

An objective analysis of the observed spatial structure of the tropical Indian Ocean SST variability  

E-Print Network (OSTI)

-mode, which influences the SST variability in the Indian quite significantly (e.g. Bjerknes 1969; Weare 1979; Latif and Barnett 1995). D. Dommenget (&) Leibniz Institute of Marine Sciences, IFM-GEOMAR, Du

Dommenget, Dietmar

464

ARM - Midlatitude Continental Convective Clouds Microwave Radiometer Profiler (jensen-mwr)  

SciTech Connect

A major component of the Mid-latitude Continental Convective Clouds Experiment (MC3E) field campaign was the deployment of an enhanced radiosonde array designed to capture the vertical profile of atmospheric state variables (pressure, temperature, humidity wind speed and wind direction) for the purpose of deriving the large-scale forcing for use in modeling studies. The radiosonde array included six sites (enhanced Central Facility [CF-1] plus five new sites) launching radiosondes at 3-6 hour sampling intervals. The network will cover an area of approximately (300)2 km2 with five outer sounding launch sites and one central launch location. The five outer sounding launch sites are: S01 Pratt, KS [ 37.7oN, 98.75oW]; S02 Chanute, KS [37.674, 95.488]; S03 Vici, Oklahoma [36.071, -99.204]; S04 Morris, Oklahoma [35.687, -95.856]; and S05 Purcell, Oklahoma [34.985, -97.522]. Soundings from the SGP Central Facility during MC3E can be retrieved from the regular ARM archive. During routine MC3E operations 4 radiosondes were launched from each of these sites (approx. 0130, 0730, 1330 and 1930 UTC). On days that were forecast to be convective up to four additional launches were launched at each site (approx. 0430, 1030, 1630, 2230 UTC). There were a total of approximately 14 of these high frequency launch days over the course of the experiment. These files contain brightness temperatures observed at Purcell during MC3E. The measurements were made with a 5 channel (22.235, 23.035, 23.835, 26.235, 30.000GHz) microwave radiometer at one minute intervals. The results have been separated into daily files and the day of observations is indicated in the file name. All observations were zenith pointing. Included in the files are the time variables base_time and time_offset. These follow the ARM time conventions. Base_time is the number seconds since January 1, 1970 at 00:00:00 for the first data point of the file and time_offset is the offset in seconds from base_time.

Jensen, Mike

2012-02-01T23:59:59.000Z

465

ARM - Midlatitude Continental Convective Clouds - Ultra High Sensitivity Aerosol Spectrometer(tomlinson-uhsas)  

SciTech Connect

Ultra High Sensitivity Aerosol Spectrometer (UHSASA) A major component of the Mid-latitude Continental Convective Clouds Experiment (MC3E) field campaign was the deployment of an enhanced radiosonde array designed to capture the vertical profile of atmospheric state variables (pressure, temperature, humidity wind speed and wind direction) for the purpose of deriving the large-scale forcing for use in modeling studies. The radiosonde array included six sites (enhanced Central Facility [CF-1] plus five new sites) launching radiosondes at 3-6 hour sampling intervals. The network will cover an area of approximately (300)2 km2 with five outer sounding launch sites and one central launch location. The five outer sounding launch sites are: S01 Pratt, KS [ 37.7oN, 98.75oW]; S02 Chanute, KS [37.674, 95.488]; S03 Vici, Oklahoma [36.071, -99.204]; S04 Morris, Oklahoma [35.687, -95.856]; and S05 Purcell, Oklahoma [34.985, -97.522]. Soundings from the SGP Central Facility during MC3E can be retrieved from the regular ARM archive. During routine MC3E operations 4 radiosondes were launched from each of these sites (approx. 0130, 0730, 1330 and 1930 UTC). On days that were forecast to be convective up to four additional launches were launched at each site (approx. 0430, 1030, 1630, 2230 UTC). There were a total of approximately 14 of these high frequency launch days over the course of the experiment. These files contain brightness temperatures observed at Purcell during MC3E. The measurements were made with a 5 channel (22.235, 23.035, 23.835, 26.235, 30.000GHz) microwave radiometer at one minute intervals. The results have been separated into daily files and the day of observations is indicated in the file name. All observations were zenith pointing. Included in the files are the time variables base_time and time_offset. These follow the ARM time conventions. Base_time is the number seconds since January 1, 1970 at 00:00:00 for the first data point of the file and time_offset is the offset in seconds from base_time.

Tomlinson, Jason; Jensen, Mike

2012-02-28T23:59:59.000Z

466

Structure of the tropical lower stratosphere as revealed by three reanalysis data sets  

SciTech Connect

While the skill of climate simulation models has advanced over the last decade, mainly through improvements in modeling, further progress will depend on the availability and the quality of comprehensive validation data sets covering long time periods. A new source of such validation data is atmospheric {open_quotes}reanalysis{close_quotes} where a fixed, state-of-the-art global atmospheric model/data assimilation system is run through archived and recovered observations to produce a consistent set of atmospheric analyses. Although reanalysis will be free of non-physical variability caused by changes in the models and/or the assimilation procedure, it is necessary to assess its quality. A region for stringent testing of the quality of reanalysis is the tropical lower stratosphere. This portion of the atmosphere is sparse in observations but displays the prominent quasi-biennial oscillation (QBO) and an annual cycle, neither of which is fully understood, but which are likely coupled dynamically. We first consider the performance of three reanalyses, from NCEP/NCAR, NASA and ECMWF, against rawinsonde data in depicting the QBO and then examine the structure of the tropical lower stratosphere in NCEP and ECMWF data sets in detail. While the annual cycle and the QBO in wind and temperature are quite successfully represented, the mean meridional circulations in NCEP and ECMWF data sets contain unusual features which may be due to the assimilation process rather than being physically based. Further, the models capture the long-term temperature fluctuations associated with volcanic eruptions, even though the physical mechanisms are not included, thus implying that the model does not mask prominent stratospheric signals in the observational data. We conclude that reanalysis offers a unique opportunity to better understand the dynamics of QBO and can be applied to climate model validation.

Pawson, S. [Free Univ. of Berlin (Germany). Institute for Meteorology; Fiorino, M. [Lawrence Livermore National Lab., CA (United States)

1996-05-01T23:59:59.000Z

467

Regional Contrast of Mesoscale Convective System Structure prior to and during Monsoon Onset across South America  

E-Print Network (OSTI)

South America THOMAS M. RICKENBACH, ROSANA NIETO-FERREIRA, AND RICHARD P. BARNHILL* Department across tropical and subtropical South America. The approach is to contrast regional differences tropical South America has the characteristic summertime maximum of a monsoon climate (Kousky 1988; Horel

Nesbitt, Steve

468

Convective heat and mass transfer and evolution of the moisture distribution in combined convection and radio frequency drying  

SciTech Connect

In a previous study (Dostie and Navarri, 1994), experiments indicated that a non-uniform moisture distribution could develop in radio frequency drying depending on the applied power and initial conditions, making the design and scale-up of such a dryer a more difficult task. Consequently, a thorough study of the combined convection and RF drying process was undertaken. Experimental results have shown that the values of the heat and mass transfer coefficients decrease with an increase in evaporation rate caused by RF energy. This effect is adequately taken into account by the boundary layer theory. Furthermore, the usual analogy between heat and mass transfer has been verified to apply in RF drying. Experiments have also shown that a different mass transfer resistance on both sides of the product should not result in non-uniform drying. However, it appears that non-uniform drying is dependent upon the initial moisture distribution and the relative intensity of heat transfer by convection and RF. It was shown that the maximum drying rate occurs at a higher average water content and that the total drying time increases with non-uniformity of the initial moisture distribution.

Poulin, A.; Dostie, M.; Kendall, J. [LTEE d`Hydro-Quebec, Shawinigan, Quebec (Canada); Proulx, P. [Univ. de Sherbrooke, Quebec (Canada)

1997-10-01T23:59:59.000Z

469

Orogenic Convection in Subtropical South America as Seen by the TRMM Satellite KRISTEN L. RASMUSSEN AND ROBERT A. HOUZE JR.  

E-Print Network (OSTI)

Orogenic Convection in Subtropical South America as Seen by the TRMM Satellite KRISTEN L. RASMUSSEN storms in southeastern South America are divided into three categories: storms with deep convective cores, the intense storms with wide convective cores over southeastern South America are unlike their Himalayan

Houze Jr., Robert A.

470

NUMERICAL DETERMINATION AND TREATMENT OF CONVECTIVE HEAT TRANSFER COEFFICIENT IN THE COUPLED BUILDING ENERGY AND CFD SIMULATION  

E-Print Network (OSTI)

for the correct prediction of the convective heat. A finer grid resolution in CFD does not always lead to a more conservation equations of flow on these grid cells. As shown in Figure 1(a), CFD calculates convective heat1 NUMERICAL DETERMINATION AND TREATMENT OF CONVECTIVE HEAT TRANSFER COEFFICIENT IN THE COUPLED

Chen, Qingyan "Yan"

471

ARM - Events Article  

NLE Websites -- All DOE Office Websites (Extended Search)

Interactions in California 3117: Year of Tropical Convection: Tropical Convection Fundamentals and Phenomena 3167: Novel Approaches and Constraints to Modeling of Secondary...

472

Impact of Resolution on Simulation of Closed Mesoscale Cellular Convection Identified by Dynamically Guided Watershed Segmentation  

SciTech Connect

Organized mesoscale cellular convection (MCC) is a common feature of marine stratocumulus that forms in response to a balance between mesoscale dynamics and smaller scale processes such as cloud radiative cooling and microphysics. We use the Weather Research and Forecasting model with chemistry (WRF-Chem) and fully coupled cloud-aerosol interactions to simulate marine low clouds during the VOCALS-REx campaign over the southeast Pacific. A suite of experiments with 3- and 9-km grid spacing indicates resolution-dependent behavior. The simulations with finer grid spacing have smaller liquid water paths and cloud fractions, while cloud tops are higher. The observed diurnal cycle is reasonably well simulated. To isolate organized MCC characteristics we develop a new automated method, which uses a variation of the watershed segmentation technique that combines the detection of cloud boundaries with a test for coincident vertical velocity characteristics. This ensures that the detected cloud fields are dynamically consistent for closed MCC, the most common MCC type over the VOCALS-REx region. We demonstrate that the 3-km simulation is able to reproduce the scaling between horizontal cell size and boundary layer height seen in satellite observations. However, the 9-km simulation is unable to resolve smaller circulations corresponding to shallower boundary layers, instead producing invariant MCC horizontal scale for all simulated boundary layers depths. The results imply that climate models with grid spacing of roughly 3 km or smaller may be needed to properly simulate the MCC structure in the marine stratocumulus regions.

Martini, Matus; Gustafson, William I.; Yang, Qing; Xiao, Heng

2014-11-27T23:59:59.000Z

473

Some properties of convective oscillations in porous medium  

SciTech Connect

Convective oscillations in porous media are studied numerically. A two-dimensional square, differentially heated cavity, filled with a saturated porous medium, is considered subject to linear harmonic oscillations in the vertical direction. The formulation is based on the Darcy-Boussinesq model. The problem includes three nondimensional parameters: the Rayleigh number for porous media Ra, its vibrational analog Ra{sub v}, and the nondimensional frequency f. The time-dependent Darcy-Boussinesq equations have been solved using a pseudo-spectral Chebyshev collocation method. The instantaneous fields of the established oscillatory regimes are presented. Also, some instantaneous and mean characteristics are studied and discussed. The distinctions from the case of viscous fluid alone are emphasized.

Khallouf, H.; Mojitabi, A. [Univ. Paul Sabatier, Toulouse (France); Gershuni, G.Z. [Perm State Univ. (Russian Federation). Dept. of Theoretical Physics

1996-11-08T23:59:59.000Z

474

Energy stability bounds on convective heat transport: Numerical study  

SciTech Connect

The concept of nonlinear energy stability has recently been extended to deduce bounds on energy dissipation and transport in incompressible flows, even for turbulent flows. In this approach an effective stability condition on {open_quotes}background{close_quotes} flow or temperature profiles is derived, which when satisfied ensures that the profile produces a rigorous upper estimate to the bulk dissipation. Optimization of the test background profiles in search of the lowest upper bounds leads to nonlinear Euler-Lagrange equations for the extremal profile. In this paper, in the context of convective heat transport in the Boussinesq equations, we describe numerical solutions of the Euler-Lagrange equations for the optimal background temperature and present the numerical computation of the implied bounds. {copyright} {ital 1997} {ital The American Physical Society}

Doering, C.R. [Department of Mathematics, University of Michigan, Ann Arbor, Michigan 48109-1109 (United States)] [Department of Mathematics, University of Michigan, Ann Arbor, Michigan 48109-1109 (United States); Hyman, J.M. [Theoretical Division and Center for Nonlinear Studies, MS-B284, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Theoretical Division and Center for Nonlinear Studies, MS-B284, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

1997-06-01T23:59:59.000Z

475

Wind reversals in turbulent Rayleigh-Benard convection  

E-Print Network (OSTI)

The phenomenon of irregular cessation and subsequent reversal of the large-scale circulation in turbulent Rayleigh-B\\'enard convection is theoretically analysed. The force and thermal balance on a single plume detached from the thermal boundary layer yields a set of coupled nonlinear equations, whose dynamics is related to the Lorenz equations. For Prandtl and Rayleigh numbers in the range $10^{-2} \\leq \\Pr \\leq 10^{3}$ and $10^{7} \\leq \\Ra \\leq 10^{12}$, the model has the following features: (i) chaotic reversals may be exhibited at Ra $\\geq 10^{7}$; (ii) the Reynolds number based on the root mean square velocity scales as $\\Re_{rms} \\sim \\Ra^{[0.41 ... 0.47]}$ (depending on Pr), and as $\\Re_{rms} \\sim \\Pr^{-[0.66 ... 0.76]}$ (depending on Ra); and (iii) the mean reversal frequency follows an effective scaling law $\\omega / (\

Francisco Fontenele Araujo; S. Grossmann; D. Lohse

2005-08-29T23:59:59.000Z

476

Radiative-Convective Equilibrium Revisited: the Greenhouse Effect of Clouds  

Science Journals Connector (OSTI)

A parameterized spectral radiative-convective equilibrium model is built and the heating rates and temperature profiles for various absorbers are calculated and compared with the results of a classical model. Then using an optical depth that is dependent on both the extinction coefficient and the cloud-water path the validity of the black-cloud assumption is tested. It is determined under what conditions one would need to know the liquid or ice water path of the cloud and when one can simply treat the cloud as a black object. A distribution of both ice and water clouds is inputted into the model and the global average surface temperature is obtained. The sensitivity of the surface temperature to a change in either the ice or liquid water path of the cloud is also evaluated.

R. Davies; C. Radley

2009-01-01T23:59:59.000Z

477

Discharge convective instability as modifier of nonlinear hydrodynamic spectrum  

E-Print Network (OSTI)

Discharge source is considered as modifier of flow hydrodynamic spectrum. Characteristic frequency of nonlinear spectrum and spectrum power were determined under conditions of arc sliding discharge in supersonic flow. Two stages of discharge were defined: sliding stage and still stage. It was found that stage transition occurs due to convective instability of discharge. Fraction of sliding stage in overall discharge duration is determined by averaged current that is general stable discharge parameter. This phenomenon gives opportunity to control power of pressure fluctuations spectrum. Theoretical insight of field and hydrodynamic factors influencing on pulsations frequency was achieved. Hydrodynamic resistance of discharge region and holding cathode electric field turned out to be basic factors of frequency modification. Corresponding experimental verification was taken. Basic frequency law was determined for several discharge regimes.

Sergey Kamenshchikov

2012-04-26T23:59:59.000Z

478

Field synergy principle analysis for reducing natural convection heat loss of a solar cavity receiver  

Science Journals Connector (OSTI)

Abstract Due to the operating temperature from 900 K to 1300 K produced by the concentrating ratio over 2000 in solar parabolic dish-engine system, the natural convection heat loss driven by the buoyancy force of air contributes an important role in the energy loss of cavity receiver. 3-D numerical simulations were performed and the results are analyzed from the novel viewpoint of field synergy principle (FSP) in order to study the heat transfer and fluid flow characteristics in natural convection heat loss of cavity receiver. The effects of geometric parameters, including the inclination angle, aperture size, aperture position and cavity geometric shape on the natural convection heat loss of cavity receiver were examined. The FSP analysis on the simulation results demonstrates that FSP can well explain the reduction mechanism for natural convection heat loss of cavity receiver because the smaller inner production of velocity vector and temperature gradient always corresponds to the lower Nusselt number occurred in the cases with lager inclination angle, smaller aperture size, lower aperture position and frustum-cylinder cavity, respectively. Therefore, the reducing natural convection heat loss attributes to the weakening synergy between velocity vector and temperature gradient. In addition, the local heat transfer performance is studied by the presented distributions of heat transferred via fluid motion, where more interesting natural convection heat loss characteristics of cavity receiver and the detailed explanations were provided. The results of this work offer benefits for the development of theory and technique about reducing natural convection heat loss of cavity receiver.

Yuqiang Li; Gang Liu; Zhenghua Rao; Shengming Liao

2015-01-01T23:59:59.000Z

479

Effects of turbulence model on convective heat transfer of coolant flow in a prismatic very high temperature reactor core  

SciTech Connect

The existing study of Spall et al. shows that only {nu}{sup 2}-f turbulence model well matches with the experimental data of Shehata and McEligot which were obtained under strongly heated gas flows. Significant over-predictions in those literatures were observed in the convective heat transfer with the other famous turbulence models such as the k-{epsilon} and k-{omega} models. In spite of such good evidence about the performance of the{nu}{sup 2}-f model, the application of the {nu}{sup 2}-f model to the thermo-fluid analysis of a prismatic core is very rare. In this paper, therefore, the convective heat transfer of the coolant flow in a prismatic core has been investigated using the {nu}{sup 2}-f model. Computational fluid dynamics (CFD) calculations have been carried out for the typical unit cell geometry of a prismatic fuel column with typical operating conditions of prismatic designs. The tested Reynolds numbers of the coolant flow are 10,000, 20,000, 30,000 and 50,000. The predicted Nusselt numbers with the {nu}{sup 2}-f model are compared with the results by the other turbulence models (k-{epsilon} and SST) as well as the empirical correlations. (authors)

Lee, S. N.; Tak, N. I.; Kim, M. H.; Noh, J. M. [Korea Atomic Energy Research Inst., Daedeok-daero 989-11, Yuseong-gu, Daejeon (Korea, Republic of)

2012-07-01T23:59:59.000Z

480

Tropical Africa: Land Use, Biomass, and Carbon Estimates for 1980  

NLE Websites -- All DOE Office Websites (Extended Search)

Tropical Africa: Land Use, Biomass, and Carbon Estimates for 1980 (NDP-055) Tropical Africa: Land Use, Biomass, and Carbon Estimates for 1980 (NDP-055) DOI: 10.3334/CDIAC/lue.ndp055 data Data PDF PDF graphics Graphics Please note: these data have been updated for the year 2000 Contributors Sandra Brown1 Greg Gaston2 Work on this project was initiated while at the Department of Natural Resources and Environmental Sciences University of Illinois Urbana, Illinois 61801, U.S.A. 1Present address: Winrock International, Arlington, Virgina. 2Present address: Department of Geosciences, Oregon State University. Prepared by T.W. Beaty, and L.M. Olsen. Carbon Dioxide Information Analysis Center Environmental Sciences Division OAK RIDGE NATIONAL LABORATORY Oak Ridge, Tennessee 37831-6290 managed by UT-Battelle, LLC for the U.S. DEPARTMENT OF ENERGY

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481

NPP Tropical Forest: San Carlos De Rio Negro, Venezuela  

NLE Websites -- All DOE Office Websites (Extended Search)

San Carlos De Rio Negro, Venezuela, 1975-1984 San Carlos De Rio Negro, Venezuela, 1975-1984 [PHOTOGRAPH] Photograph: Cutting an experimental plot at San Carlos (click on the photo to view a series of images and a diagram of this site) Data Citation Cite this data set as follows: Jordan, C. F., E. Cuevas, and E. Medina. 1999. NPP Tropical Forest: San Carlos de Rio Negro, Venezuela, 1975-1984. Data set. Available on-line [http://www.daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A. Description Productivity of tropical forest was determined for a number of vegetation-soil associations at the San Carlos de Rio Negro study site, under the auspices of an international UNESCO Man and the Biosphere (MAB) project. The San Carlos study site (1.93 N 67.05 W) is situated 4 km east of the

482

Geographical Distribution of Biomass Carbon in Tropical Southeast Asian  

NLE Websites -- All DOE Office Websites (Extended Search)

Geographical Distribution of Biomass Carbon in Tropical Southeast Asian Geographical Distribution of Biomass Carbon in Tropical Southeast Asian Forests: A Database (NDP-068) DOI: 10.3334/CDIAC/lue.ndp068 data Data PDF PDF Appendix A is reprint of Brown et al. paper in Geocarto International, Vol. 8; copyright 1993 Geocarto International Centre and reprinted with kind permission from the publisher) image Contributors Sandra Brown1 Louis R. Iverson2 Anantha Prasad2 Department of Natural Resources and Environmental Sciences University of Illinois Urbana, Illinois 1Present address: Winrock International, Arlington, Virginia 2Present address: United States Forest Service, Northeast Research Station, Delaware, Ohio Prepared by Tammy W. Beaty, Lisa M. Olsen, Robert M. Cushman, and Antoinette L. Brenkert Carbon Dioxide Information Analysis Center

483

The Role of Disturbance in Dry Tropical Forest Landscapes  

SciTech Connect

Disturbance can be defined as 'any relatively discrete event in time that disrupts ecosystem, community, or population structure and changes resources, substrate availability, or the physical environment'. This definition requires that the spatial and temporal scales of the system and disturbance be determined. Disturbances are typically characterized by their size, spatial distribution, frequency or return time, predictability, and magnitude (which includes both intensity and severity). These disturbance attributes set the parameters for the suite of species, both plant and animal, that can persist within a given system. As such, an understanding of seasonally dry tropical forests in Asia requires an understanding of disturbance within the region. However, disturbances are relatively poorly understood in dry tropical forests, partly because of the weak seasonality in temperature and high tree species diversity of these forests relative to most forest systems of the world. There are about 1,048,700 km{sup 2} of dry tropical forests worldwide and that only 3% of this land is in conservation status. In other words, 97% of the world's seasonally dry tropical forest is at risk of human disturbance. About half of this forest occurs in South America, where most of the conservation lands are located. Satellite imagery based on MODIS (Moderate Resolution Imaging Spectroradiometer) data shows that only about 3.8% of the world's dry tropical forests are in Australia and South east Asia. The susceptibility of these forests to human disturbances is of great concern and is largely unstudied. Because natural disturbance regimes shape the ecosystem structure and are in many ways integral to these forest systems, it is critical to know how natural disturbance affects dry forest in order to understand the effects of human activities on these forests. Even basic information about disturbances in dry tropical forests is only recently available. Therefore this chapter brings together much of the available information from dry tropical forest throughout the world with the goal of developing an understanding of the role of disturbance in Asian dry forests. Most ecologists now recognize that disturbances, rather than being catastrophic agents of destruction, are a normal, perhaps even an integral, part of long-term system dynamics. The composition, structure, organization, and development and trophic dynamics of most forest systems are the products of disturbances. As an example, the forest composition for two disturbances in the Anaikatty Hills of Western Ghats were compared, where the low disturbance was from past logging followed by cutting and illicit felling and grazing and the high disturbance was due to human presence, past logging, and fuelwood collection. They found higher species richness and Shannon-Wiener diversity index for the low-disturbance forest (98 and 3.9, respectively) compared to the high-disturbance stand (45 and 2.71, respectively) as well as significant differences in mean basal area of trees, density of seedlings, number of species, density and diversity of shrubs, and number of species and diversity of herbs. Some ecological systems contain species that have evolved in response to disturbances. Adaptations typical of dry tropical forest plants are drought tolerance, seed dispersal mechanisms, and the ability to sprout subsequent to disturbance. In contrast, evidence was found that human disturbance in Kakamega Forest of western Kenya has significantly reduced allelic richness and heterozygosity, increased inbreeding, and slightly reduced gene flow in Prunus africana in the past century.

Dale, Virginia H [ORNL

2011-01-01T23:59:59.000Z

484

Towards a new scheme for parametrisation of deep convection in NAME III  

Science Journals Connector (OSTI)

This paper describes an updated scheme for parametrisation of atmospheric convection to be used in the Met Office Atmospheric Dispersion Model (NAME III). In this scheme, the vertical transport of particles due to convection is represented in a 1-dimensional model based on a 'mass-flux' approach. Empirical formulas are used to obtain the mass fluxes and the convective precipitation is used for closure. Results compared with the mass fluxes from the single column version of the Met Office's NWP model show good agreement. Lastly, an alternative method to estimate the mass fluxes by calculating a dilute parcel ascent is also discussed.

Elena Meneguz; David J. Thomson

2014-01-01T23:59:59.000Z

485

Meteorological significance of frontal thin-line angel echoes observed by CPS-9 radar  

E-Print Network (OSTI)

Effects of Vertical Wind-Shear on Convection Cells in the Atmosphere and Ocean 83 86 C. Radar Observations of Benard Cells and the Effects of Vertical Wind-Shear 89 D. Possible Effects of Wind-Shear Modified Convection Cells Exhibited by the Angel... of the Relationship between Wind-shear and Angel Echo Patterns 102 D. Summary of Conclusions REFERENCES APPENDIX 103 105 110 LIST OF FIGURES Figure 1. Surface Nap, 1500C, 10 December 1957 2. PPI Photographs~ 10 December 1957 3. Cold-frontal and Thin...

Miller, Donald Bradford

2012-06-07T23:59:59.000Z

486

Universidade de Braslia Faculdade de Medicina Programa de Ps-Graduao em Medicina Tropical  

E-Print Network (OSTI)

Universidade de Brasília ­ Faculdade de Medicina Programa de Pós-Graduação em Medicina Tropical Edital n o . 1/2012 1 PROGRAMA DE P�S-GRADUA��O EM MEDICINA TROPICAL EDITAL No. 01/2012 SELE��O DE CANDIDATOS �S VAGAS DO PROGRAMA DE P�S-GRADUA��O EM MEDICINA TROPICAL PARA OS CURSOS DE MESTRADO ACAD�MICO E

Maier, Rudolf Richard

487

UNIVERSIDADE DE BRASLIA PROGRAMA DE PS-GRADUAO EM MEDICINA TROPICAL  

E-Print Network (OSTI)

UNIVERSIDADE DE BRASÍLIA PROGRAMA DE P�S-GRADUA��O EM MEDICINA TROPICAL EDITAL No. 02/2010 SELE��O DE CANDIDATOS �S VAGAS DO PROGRAMA DE P�S-GRADUA��O EM MEDICINA TROPICAL PARA OS CURSOS DE MESTRADO Pós-Graduação em Medicina Tropical, no uso de suas atribuições legais, torna público e estabelece

Maier, Rudolf Richard

488

UNIVERSIDADE DE BRASLIA PROGRAMA DE PS-GRADUAO EM MEDICINA TROPICAL  

E-Print Network (OSTI)

UNIVERSIDADE DE BRASÍLIA PROGRAMA DE P�S-GRADUA��O EM MEDICINA TROPICAL EDITAL No. 01/2009 SELE��O DE CANDIDATOS �S VAGAS DO PROGRAMA DE P�S-GRADUA��O EM MEDICINA TROPICAL PARA OS CURSOS DE MESTRADO INFECCIOSAS E PARASITÁRIAS 1. PRE�MBULO 1.1 O Coordenador do Programa de Pós-Graduação em Medicina Tropical

Maier, Rudolf Richard

489

UNIVERSIDADE DE BRASLIA PROGRAMA DE PS-GRADUAO EM MEDICINA TROPICAL  

E-Print Network (OSTI)

UNIVERSIDADE DE BRASÍLIA PROGRAMA DE P�S-GRADUA��O EM MEDICINA TROPICAL EDITAL No. 03/2011 SELE��O DE CANDIDATOS �S VAGAS DO PROGRAMA DE P�S-GRADUA��O EM MEDICINA TROPICAL PARA OS CURSOS DE MESTRADO Graduação em Medicina Tropical, no uso de suas atribuições legais, torna público e estabelece a retificação

Lucero, Jorge Carlos

490

UNIVERSIDADE DE BRASLIA PROGRAMA DE PS-GRADUAO EM MEDICINA TROPICAL  

E-Print Network (OSTI)

1 UNIVERSIDADE DE BRASÍLIA PROGRAMA DE P�S-GRADUA��O EM MEDICINA TROPICAL EDITAL No. 02/2011 SELE��O DE CANDIDATOS �S VAGAS DO PROGRAMA DE P�S-GRADUA��O EM MEDICINA TROPICAL PARA OS CURSOS DE de Pós Graduação em Medicina Tropical, no uso de suas atribuições legais, torna público e estabelece

Lucero, Jorge Carlos

491

E-Print Network 3.0 - abrupt tropical climate Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

tropical climate Page: << < 1 2 3 4 5 > >> 1 Long-term climate variability and abrupt climate change Instructor: Dr. Igor Kamenkovich, associate professor Summary: Long-term...

492

Relationships between global warming and tropical cyclone activity in the Western North Pacific .  

E-Print Network (OSTI)

??In this work, we investigate the relationships between global warming and tropical cyclone activity in the Western North Pacific (WNP). Our hypothesis is that global… (more)

Meyer, David W.

2007-01-01T23:59:59.000Z

493

E-Print Network 3.0 - asian tropical rain Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

out that in the case of tropical cyclones or warm rain, substantial amounts... the flash density. CG-lightning and precipitation data are used to compute the values ......

494

E-Print Network 3.0 - afromontane tropical forest Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

OWEN T. LEWIS1 AND ... Source: Basset, Yves - Smithsonian Tropical Research Institute, Panama Collection: Environmental Sciences and Ecology 16 A Reference Guide to Conflicting...

495

Connection of the Panama fracture zone with the Galapagos rift zone, eastern tropical Pacific  

Science Journals Connector (OSTI)

Magnetic data recently collected in the eastern tropical Pacific confirm that the Galapagos rift zone is connected to the Panama fracture zone by a short north-south...

Paul J. Grim

1970-08-01T23:59:59.000Z

496

Deep Signatures of Southern Tropical Indian Ocean Annual Rossby Waves* GREGORY C. JOHNSON  

E-Print Network (OSTI)

Deep Signatures of Southern Tropical Indian Ocean Annual Rossby Waves* GREGORY C. JOHNSON NOAA Environmental Laboratory Contribution Number 3671. Corresponding author address: Gregory C. Johnson, NOAA

Johnson, Gregory C.

497

E-Print Network 3.0 - annual tropical cyclone Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

of tropical ... Source: Kossin, James P. - Cooperative Institute of Meteorological Satellite Studies, University of Wisconsin at Madison Collection: Geosciences 11 Ch.8...

498

Tropical Pacific nutrient dynamics in the modern and Pleistocene ocean| Insights from the nitrogen isotope system.  

E-Print Network (OSTI)

?? The tropical Pacific is a region where nutrient delivery, upper ocean dynamics, and global climate variability are tightly coupled. For example, the depth of… (more)

Rafter, Patrick Anthony

2009-01-01T23:59:59.000Z

499

Tropical Pacific nutrient dynamics in the modern and pleistocene ocean : insights from the nitrogen isotope system.  

E-Print Network (OSTI)

??The tropical Pacific is a region where nutrient delivery, upper ocean dynamics, and global climate variability are tightly coupled. For example, the depth of the… (more)

Rafter, Patrick Anthony

2009-01-01T23:59:59.000Z

500

Analytic model of upper tropospheric clouds in the tropical Hadley cell  

Science Journals Connector (OSTI)

We have developed a two-dimensional analytic model that describes the behavior of upper tropospheric clouds in the tropical Hadley cell. The behavior of the model is...

Kyoko K. Tanaka; Tetsuo Yamamoto; Sei-ichiro Watanabe…

2008-03-01T23:59:59.000Z