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Note: This page contains sample records for the topic "measurement variable convection" 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

Tropical Convective Variability as 1/f Noise  

Science Conference Proceedings (OSTI)

Evidence is presented that the tropical convective variability behaves as 1/f noise for a 1–30-day period. This behavior is shown by analyzing the time series of convective available potential energy, which measures the degree of convective ...

Jun-Ichi Yano; Klaus Fraedrich; Richard Blender

2001-09-01T23:59:59.000Z

2

Thermodynamic Variability within the Convective Boundary Layer Due to Horizontal Convective Rolls  

Science Conference Proceedings (OSTI)

Data from the Convection and Precipitation/Electrification (CaPE) Experiment conducted during the summer of 1991 are used to examine and quantify the horizontal variability of temperature and moisture within the convective boundary layer (CBL). ...

Tammy M. Weckwerth; James W. Wilson; Roger M. Wakimoto

1996-05-01T23:59:59.000Z

3

Temperature and Salinity Variability in Heterogeneous Oceanic Convection  

Science Conference Proceedings (OSTI)

In regions of active oceanic convection, such as the Labrador Sea, small- and mesoscale spatial variability is observed in the temperature and salinity fields (T and S). Often T and S structures are “density-compensated,” with the density ...

Sonya Legg; James C. McWilliams

2000-06-01T23:59:59.000Z

4

Measurement of Convective Entrainment Using Lagrangian Particles  

Science Conference Proceedings (OSTI)

Lagrangian particle tracking is used in a large-eddy simulation to study an individual cumulus congestus. This allows for the direct measurement of the convective entrainment rate and of the residence times of entrained parcels within the cloud. ...

Kyongmin Yeo; David M. Romps

2013-01-01T23:59:59.000Z

5

Convective–Stratiform Precipitation Variability at Seasonal Scale from 8 Yr of TRMM Observations: Implications for Multiple Modes of Diurnal Variability  

Science Conference Proceedings (OSTI)

This study investigates the variability of convective and stratiform rainfall from 8 yr (1998–2005) of Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) and TRMM Microwave Imager (TMI) measurements, focusing on seasonal diurnal ...

Song Yang; Eric A. Smith

2008-08-01T23:59:59.000Z

6

Mechanisms for Precipitation Variability of the Eastern Brazil/SACZ Convective Margin  

Science Conference Proceedings (OSTI)

The present study examines the mechanisms for the connection between the precipitation variability in eastern Brazil and the South Atlantic convergence zone (SACZ) convective margin (eastern Brazil/SACZ convective margin) and the variability of ...

H.-Y. Ma; X. Ji; J. D. Neelin; C. R. Mechoso

2011-07-01T23:59:59.000Z

7

A Systemic Analysis of Multiscale Deep Convective Variability over the Tropical Pacific  

Science Conference Proceedings (OSTI)

The multiscale tropical deep convective variability over the Pacific Ocean is examined with the 4-month high-resolution deep convection index (ITBB) derived from satellite imagery. With a systemic view, the complex phenomenon is described with ...

Wen-wen Tung; Mitchell W. Moncrieff; Jian-Bo Gao

2004-07-01T23:59:59.000Z

8

Quasi-Lagrangian Measurements in Convective Boundary Layer Plumes and Their Implications for the Calculation of CAPE  

Science Conference Proceedings (OSTI)

Measurements were made to determine the level of origin of air parcels participating in natural convection. Lagrangian measurements of conservative variables are ideal for this purpose. A simple remotely piloted vehicle was developed to make in ...

Nilton O. Rennó; Earle R. Williams

1995-09-01T23:59:59.000Z

9

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

Science Conference Proceedings (OSTI)

Ten years (1994–2004) of measurements of tropical upper-tropospheric water vapor (UTWV) by the Measurement of Ozone and Water Vapor by Airbus In-Service Aircraft (MOZAIC) are investigated over three regions—the tropical Atlantic, tropical Africa, ...

Zhengzhao Luo; Dieter Kley; Richard H. Johnson; Herman Smit

2007-02-01T23:59:59.000Z

10

Second law analysis for a variable viscosity plane Poiseuille flow with asymmetric convective cooling  

Science Conference Proceedings (OSTI)

A second-law analysis of a pressure-driven variable viscosity fluid flow through a channel with asymmetric convective cooling at the walls is investigated. Flow is assumed to be steady, laminar and fully-developed. The effect of heat generation due to ... Keywords: Asymmetric convective cooling, Entropy generation analysis, Poiseuille flow, Variable viscosity

O. D. Makinde; A. Aziz

2010-12-01T23:59:59.000Z

11

Measurement of Simulated Convective Temperature Distribution Near Ancient Wall Paintings  

Science Conference Proceedings (OSTI)

This study presents a method for measuring the temperature distribution in a confined volume of water used to simulate heat convection in the air. The water was seeded with thermo sensitive crystals as an indicator for the temperature. A 1:10 scale model ... Keywords: air modeling in water, natural convection, thermo-sensitive liquid crystals

V. S. Fonov; C. F. Joeckel; I. Grant

2001-04-01T23:59:59.000Z

12

Natural convection flow over an inclined flat plate with internal heat generation and variable viscosity  

Science Conference Proceedings (OSTI)

The present investigation deals with study of laminar natural convection flow of a viscous fluid over a semi-infinite flat plate inclined at a small angle to the horizontal with internal heat generation and variable viscosity. The dimensionless boundary ... Keywords: Heat generation, Inclined flat surface, Natural convection, Temperature dependent viscosity

S. Siddiqa; S. Asghar; M. A. Hossain

2010-11-01T23:59:59.000Z

13

A Simple Method for Measuring Deep Convection  

Science Conference Proceedings (OSTI)

The glass-pipe technology used for RAFOS floats is applied to the monitoring of convection in deep mixed layers. The velocity of a vertical current is estimated from the relationship between the drag force exerted on a float by the vertical ...

Edward J. Kearns; H. Thomas Rossby

1993-08-01T23:59:59.000Z

14

Convectively Coupled Kelvin Waves over Tropical Africa during the Boreal Summer: Structure and Variability  

Science Conference Proceedings (OSTI)

The structure and variability of convectively coupled Kelvin waves during the boreal summer are explored using satellite-observed brightness temperature data and ECMWF reanalyses. Kelvin wave activity is most prominent between the central and ...

Ademe Mekonnen; Chris D. Thorncroft; Anantha R. Aiyyer; George N. Kiladis

2008-12-01T23:59:59.000Z

15

A Satellite Study of Tropical Moist Convection and Environmental Variability: A Moisture and Thermal Budget Analysis  

Science Conference Proceedings (OSTI)

The thermodynamic variability associated with moist convection over tropical oceans is analyzed by making use of a variety of satellite sensors including radars, an infrared and microwave sounder unit, and a microwave radiometer and scatterometer ...

Hirohiko Masunaga

2013-08-01T23:59:59.000Z

16

2–3-Day Convective Variability in the Tropical Western Pacific  

Science Conference Proceedings (OSTI)

This paper is an examination of 2–3-day convective variability in the tropical Pacific region. The initial focus of the paper is on the western tropical Pacific during the Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response ...

Carol Anne Clayson; Brian Strahl; Jon Schrage

2002-03-01T23:59:59.000Z

17

Variability of Updraft and Downdraft Characteristics in a Large Parameter Space Study of Convective Storms  

Science Conference Proceedings (OSTI)

Over 200 convective storm simulations are analyzed to examine the variability in storm vertical velocity and updraft area characteristics as a function of basic environmental parameters. While it is known that bulk properties of the troposphere ...

Cody Kirkpatrick; Eugene W. McCaul Jr.; Charles Cohen

2009-05-01T23:59:59.000Z

18

A Satellite Study of Tropical Moist Convection and Environmental Variability: A Moisture and Thermal Budget Analysis  

Science Conference Proceedings (OSTI)

The thermodynamic variability associated with moist convection over tropical oceans is analyzed by making use of a variety of satellite sensors including radars, an infrared and microwave sounder unit, and microwave radiometer and scatterometer ...

Hirohiko Masunaga

19

Conserved Variable Analysis of the Convective Boundary Layer Thermodynamic Structure over the Tropical Oceans  

Science Conference Proceedings (OSTI)

An analysis of FGGE dropwindsonde data using conserved thermodynamic variables shows mixing line structures for the convective boundary layer over the equatorial Pacific. Deeper boundary layers show a double structure. Reversals of the gradients ...

Alan K. Betts; Bruce A. Albrecht

1987-01-01T23:59:59.000Z

20

Natural convection airflow measurement and theory  

DOE Green Energy (OSTI)

Natural convection is a major mechanism for heat distribution in many passive solar buildings, especially those with sunspaces. To better understand this mechanism, observations of air velocities and temperatures have been made in 13 different houses that encompass a wide variety of one- and two-story geometries. This paper extends previous reports. Results from one house are described in detail, and some generalizations are drawn from the large additional mass of data taken. A simple mathematical model is presented that describes the general nature of airflow and energy flow through an aperture.

Balcomb, J.D.; Jones, G.F.; Yamaguchi, Kenjiro

1984-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "measurement variable convection" 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

Atmospheric Radiation Measurement Convective and Orographically...  

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

Induced Precipitation Study The U.S. Department of Energy's Atmospheric Radiation Measurement (ARM) Climate Research Facility is providing the ARM Mobile Facility...

22

Plume Dispersion in the Convective Boundary Layer. Part I: CONDORS Field Experiment and Example Measurements  

Science Conference Proceedings (OSTI)

Project CONDORS (CONvective Diffusion Observed by Remote Sensors) measured the dispersion of a nonbuoyant plume in the highly convective boundary layer. Laboratory and numerical models have predicted vertical profiles of a passive tracer that are ...

W. L. Eberhard; W. R. Moninger; G. A. Briggs

1988-05-01T23:59:59.000Z

23

Regional Variability in Tropical Convection: Observations from TRMM  

Science Conference Proceedings (OSTI)

Observation of the vertical profile of precipitation over the global Tropics is a key objective of the Tropical Rainfall Measuring Mission (TRMM) because this information is central to obtaining vertical profiles of latent heating. This study ...

Walter A. Petersen; Steven A. Rutledge

2001-09-01T23:59:59.000Z

24

Radar Observations of Convective System Variability in Relationship to African Easterly Waves during the 2006 AMMA Special Observing Period  

E-Print Network (OSTI)

A radar-based analysis of the structure, motion, and rainfall variability of westward-propagating squall-line mesoscale convective systems (SLMCSs) in Niamey, Niger, during the African Monsoon Multidisciplinary Activities ...

Williams, Earle R.

25

Radar Observations of Convective System Variability in Relationship to African Easterly Waves during the 2006 AMMA Special Observing Period  

Science Conference Proceedings (OSTI)

A radar-based analysis of the structure, motion, and rainfall variability of westward-propagating squall-line mesoscale convective systems (SLMCSs) in Niamey, Niger, during the African Monsoon Multidisciplinary Activities (AMMA) 2006 special ...

Rosana Nieto Ferreira; Thomas Rickenbach; Nick Guy; Earle Williams

2009-12-01T23:59:59.000Z

26

Group Analysis of Variable Coefficient Diffusion--Convection Equations. III. Conservation Laws  

E-Print Network (OSTI)

The notions of generating sets of conservation laws of systems of differential equations with respect to symmetry groups and equivalence groups are introduced and applied. This allows us to generalize essentially the procedure of finding potential symmetries for the systems with multidimensional spaces of conservation laws. A class of variable coefficient (1+1)-dimensional nonlinear diffusion-convection equations of general form $f(x)u_t=(g(x)A(u)u_x)_x+h(x)B(u)u_x$ is investigated. Using the most direct method, we carry out two classifications of local conservation laws up to equivalence relations generated by both usual and enhanced equivalence groups. Equivalence with respect to $\\hat G^{\\sim}$ and correct choice of gauge coefficients of equations play the major role for simple and clear formulation of the final results. The notion of contractions of conservation laws and one of characteristics of conservation laws are introduced and contractions of conservation laws of diffusion-convection equations are found.

N. M. Ivanova; R. O. Popovych; C. Sophocleous

2007-10-16T23:59:59.000Z

27

An Approximate Footprint Model for Flux Measurements in the Convective Boundary Layer  

Science Conference Proceedings (OSTI)

An explicit footprint model for flux measurements of passive scalars in the lower part of the convective boundary layer (CBL) is introduced. A simple footprint model is derived analytically in an idealized CBL. The simple model can simulate the ...

Weiguo Wang; Kenneth J. Davis; Daniel M. Ricciuto; Martha P. Butler

2006-10-01T23:59:59.000Z

28

Measuring the Global Distribution of Intense Convection over Land with Passive Microwave Radiometry  

Science Conference Proceedings (OSTI)

The global distribution of intense convective activity over land is shown to be measurable with satellite passive-microwave methods through a comparison of an empirical rain rate algorithm with a climatology of thunderstorm days for the months of ...

Roy W. Spencer; David A. Santek

1985-08-01T23:59:59.000Z

29

Improving Convective Precipitation Forecasting through Assimilation of Regional Lightning Measurements in a Mesoscale Model  

Science Conference Proceedings (OSTI)

A technique developed for assimilating regional lightning measurements into a meteorological model is presented in this paper. The goal is to assess the effectiveness of cloud-to-ground (CG) lightning information for improving the convective ...

Anastasios Papadopoulos; Themis G. Chronis; Emmanouil N. Anagnostou

2005-07-01T23:59:59.000Z

30

A technique to measure turbulent free convective heat transfer in a vertical tall cavity.  

E-Print Network (OSTI)

??A time-average technique was developed to measure the unsteady and turbulent free convection heat transfer in tall vertical enclosure using a Mach-Zehnder interferometer. The method… (more)

Poulad, Mohammad Ebrahim

2009-01-01T23:59:59.000Z

31

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

32

Sources of Mesoscale Variability of Gravity Waves. Part II: Frontal, Convective, and Jet Stream Excitation  

Science Conference Proceedings (OSTI)

We present studies of four cases of mesoscale variance enhancements of horizontal velocity and temperature due to frontal activity, nonfrontal convection, and wind shear. These data were obtained aboard commercial aircraft during the Global ...

David C. Fritts; Gregory D. Nastrom

1992-01-01T23:59:59.000Z

33

The “Year” of Tropical Convection (May 2008–April 2010): Climate Variability and Weather Highlights  

Science Conference Proceedings (OSTI)

The representation of tropical convection remains a serious challenge to the skillfulness of our weather and climate prediction systems. To address this challenge, the World Climate Research Programme (WCRP) and The Observing System Research and ...

Duane E. Waliser; Mitchell W. Moncrieff; David Burridge; Andreas H. Fink; Dave Gochis; B. N. Goswami; Bin Guan; Patrick Harr; Julian Heming; Huang-Hsuing Hsu; Christian Jakob; Matt Janiga; Richard Johnson; Sarah Jones; Peter Knippertz; Jose Marengo; Hanh Nguyen; Mick Pope; Yolande Serra; Chris Thorncroft; Matthew Wheeler; Robert Wood; Sandra Yuter

2012-08-01T23:59:59.000Z

34

Retrieval of Thermodynamic Variables within Deep Convective Clouds: Experiments in Three Dimensions  

Science Conference Proceedings (OSTI)

A three-dimensional thermodynamic retrieval method has been developed and tested for application to deep convective clouds. To test the accuracy of the method and for sensitivity studies, output from a three-dimensional numerical cloud model has ...

Carl E. Hane; Robert B. Wilhelmson; Tzvi Gal-Chen

1981-03-01T23:59:59.000Z

35

Variability of Graupel and Snow Observed in Tropical Oceanic Convection by Aircraft during TRMM KWAJEX  

Science Conference Proceedings (OSTI)

Empirical characterization of graupel and snow in precipitating tropical convective clouds is important for refining satellite precipitation retrieval algorithms and cloud-resolving and radiative transfer models. Microphysics data for this ...

Ellen M. Sukovich; David E. Kingsmill; Sandra E. Yuter

2009-02-01T23:59:59.000Z

36

Submonthly Convective Variability over South America and the South Atlantic Convergence Zone  

Science Conference Proceedings (OSTI)

Relationships between deep convection over South America and the atmospheric circulation are examined, with emphasis on submonthly variations of the South Atlantic convergence zone (SACZ) during austral summer. Outgoing longwave radiation (OLR) ...

Brant Liebmann; George N. Kiladis; JoséA. Marengo; Tércio Ambrizzi; John D. Glick

1999-07-01T23:59:59.000Z

37

Global Variability of Mesoscale Convective System Anvil Structure from A-Train Satellite Data  

Science Conference Proceedings (OSTI)

Mesoscale convective systems (MCSs) in the tropics produce extensive anvil clouds, which significantly affect the transfer of radiation. This study develops an objective method to identify MCSs and their anvils by combining data from three A-...

Jian Yuan; Robert A. Houze Jr.

2010-11-01T23:59:59.000Z

38

A Study of Two-Dimensional Dry Convective Plume Modes with Variable Critical Level Height  

Science Conference Proceedings (OSTI)

This study investigates the impact of wind speed and critical level height on dry convection above a prescribed heat source. This is done using the Advanced Regional Prediction System (ARPS) model in its two-dimensional form with an imposed 400-K ...

Michael T. Kiefer; Yuh-Lang Lin; Joseph J. Charney

2008-02-01T23:59:59.000Z

39

Double-diffusive convection with variable viscosity from a vertical truncated cone in porous media in the presence of magnetic field and radiation effects  

Science Conference Proceedings (OSTI)

This work is focused on the study of combined heat and mass transfer or double-diffusive convection near a vertical truncated cone embedded in a fluid-saturated porous medium in the presence of thermal radiation, magnetic field and variable viscosity ... Keywords: Double diffusion, Magnetic field, Porous media, Radiation, Truncated cone, Variable viscosity

A. Mahdy; A. J. Chamkha; Yousef Baba

2010-06-01T23:59:59.000Z

40

Aerosol Size Spectra in a Convective Marine Layer with Stratus: Results of Airborne Measurements near San Nicolas Island, California  

Science Conference Proceedings (OSTI)

Airborne measurements of the aerosol size spectra n (r) (r is radius) were made in a vertical plane extending northeastward 18 km from San Nicolas Island, California. Thin, patchy, stratus clouds were present in a deepening convective marine ...

V. Ray Noonkester

1981-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "measurement variable convection" 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

Convective Precipitation Variability as a Tool for General Circulation Model Analysis  

Science Conference Proceedings (OSTI)

Precipitation variability is analyzed in two versions of the Community Atmospheric Model (CAM), the standard model, CAM, and a “multiscale modeling framework” (MMF), in which the cumulus parameterization has been replaced with a cloud-resolving ...

Charlotte A. DeMott; David A. Randall; Marat Khairoutdinov

2007-01-01T23:59:59.000Z

42

Convective Coupling and Interannual and Intraseasonal Coupled Variabilities in the Tropics  

Science Conference Proceedings (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

43

Spatial Variability of Liquid Water Path in Marine Low Cloud: The Importance of Mesoscale Cellular Convection  

Science Conference Proceedings (OSTI)

Liquid water path (LWP) mesoscale spatial variability in marine low cloud over the eastern subtropical oceans is examined using two months of daytime retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the NASA Terra ...

Robert Wood; Dennis L. Hartmann

2006-05-01T23:59:59.000Z

44

Modeling the Variability of Sydney Harbor Wind Measurements  

Science Conference Proceedings (OSTI)

The time-dependent behavior in the variability of wind measurements is investigated using bivariate generalized autoregressive conditional heteroscedastic models. These models express the current level of short-timescale wind variability in terms ...

Edward Cripps; William T. M. Dunsmuir

2003-08-01T23:59:59.000Z

45

TRMM Observations of Intraseasonal Variability in Convective Regimes over the Amazon  

Science Conference Proceedings (OSTI)

This study utilizes the Tropical Rainfall Measuring Mission (TRMM) satellite precipitation radar (PR), lightning imaging sensor (LIS), and passive microwave imager (TMI) data together with ground-based lightning data to investigate the vertical ...

Walter A. Petersen; Stephen W. Nesbitt; Richard J. Blakeslee; Robert Cifelli; Paul Hein; Stephen A. Rutledge

2002-06-01T23:59:59.000Z

46

Interannual to Diurnal Variations in Tropical and Subtropical Deep Convective Clouds and Convective Overshooting from Seven Years of AMSU-B Measurements  

Science Conference Proceedings (OSTI)

This study surveys interannual to diurnal variations of tropical deep convective clouds and convective overshooting using the Advanced Microwave Sounding Unit B (AMSU-B) aboard the NOAA polar orbiting satellites from 1999 to 2005. The methodology ...

Gang Hong; Georg Heygster; Justus Notholt; Stefan A. Buehler

2008-09-01T23:59:59.000Z

47

A Numerical Investigation of Several Factors Contributing to the Observed Variable Intensity of Deep Convection over South Florida  

Science Conference Proceedings (OSTI)

This study employs a revised version of the Colorado State University three-dimensional numerical cloud scale model to investigate the observed behavior of deep convection over South Florida on 17 July 1973. A brief description of recent model ...

Gregory J. Tripoli; William R. Cotton

1980-09-01T23:59:59.000Z

48

Retrieval of Thermal and Microphysical Variables in Observed Convective Storms. Part 1: Model Development and Preliminary Testing  

Science Conference Proceedings (OSTI)

The air flow in convective storms, the force that regulate the flow, and the processes that produce hydrometeors of various kinds are all being studied intensively by meteorologists using Doppler radar observations. The research reported here ...

Conrad L. Ziegler

1985-07-01T23:59:59.000Z

49

Sensitivity of Orographic Moist Convection to Landscape Variability: A Study of the Buffalo Creek, Colorado, Flash Flood Case of 1996  

Science Conference Proceedings (OSTI)

A number of numerical experiments with a high-resolution mesoscale model were conducted to study the convective rainfall event that caused the 1996 Buffalo Creek, Colorado, flash flood. Different surface conditions and treatments of land surface ...

Fei Chen; Thomas T. Warner; Kevin Manning

2001-11-01T23:59:59.000Z

50

The Influence of Horizontal Environmental Variability on Numerically Simulated Convective Storms. Part I: Variations in Vertical Shear  

Science Conference Proceedings (OSTI)

Severe convective storms are typically simulated using either an idealized, horizontally homogeneous environment (i.e., single sounding) or an inhomogeneous environment constructed using numerous types of observations. Representing opposite ends ...

Yvette P. Richardson; Kelvin K. Droegemeier; Robert P. Davies-Jones

2007-10-01T23:59:59.000Z

51

Evaluation of Hydrometeor Phase and Ice Properties in Cloud-Resolving Model Simulations of Tropical Deep Convection Using Radiance and Polarization Measurements  

Science Conference Proceedings (OSTI)

Satellite measurements are used to evaluate the glaciation, particle shape, and effective radius in cloud-resolving model simulations of tropical deep convection. Multidirectional polarized reflectances constrain the ice crystal geometry and the ...

Bastiaan van Diedenhoven; Ann M. Fridlind; Andrew S. Ackerman; Brian Cairns

2012-11-01T23:59:59.000Z

52

Variability in Measured Space Temperatures in 60 Homes  

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

Variability in Measured Space Variability in Measured Space Temperatures in 60 Homes David Roberts National Renewable Energy Laboratory Kerylyn Lay EnerNOC (formerly of the National Renewable Energy Laboratory) Technical Report NREL/TP-5500-58059 March 2013 NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency & Renewable Energy, operated by the Alliance for Sustainable Energy, LLC. National Renewable Energy Laboratory 15013 Denver West Parkway Golden, Colorado 80401 303-275-3000 * www.nrel.gov Contract No. DE-AC36-08GO28308 Variability in Measured Space Temperatures in 60 Homes David Roberts National Renewable Energy Laboratory Kerylyn Lay EnerNOC (formerly of the National Renewable Energy Laboratory)

53

Measurements and modeling of the effect of convective clouds on the upper tropospheric moisture budget  

SciTech Connect

The goal of this study is to determine the upper tropospheric moisture budget associated with convective events, and in particular to extend process models to higher altitudes than have been achieved previously. Although upper tropospheric moisture concentrations are several orders of magnitude lower than those near the surface, upper tropospheric moisture exerts an important influence on climate. On a per-molecule basis, greenhouse absorption due to water vapor is about one hundred times more effective at high altitudes than at low altitudes. Several one-dimensional radiative convective models have been used to demonstrate the importance of upper tropospheric moisture on climate. These models show that for a given fractional increase in water vapor at a given altitude the response or change in surface temperature is qualitatively the same. At present, considerable controversy exists over the nature of the vertical redistribution of water vapor in a changing climate, and particularly the distribution of water vapor in the upper troposphere. Lacking suitable data, this controversy is also reflected in the cumulus parameterization schemes that are currently used in models. Understanding upper tropospheric moistening processes are therefore of prime importance in addressing the water vapor feedback question.

Bisson, S.E.; Goldsmith, J.E.M. [Sandia National Labs., Livermore, CA (United States); Del Genio, A.D. [National Aeronautics and Space Administration, New York, NY (United States). Goddard Inst. for Space Studies

1994-06-01T23:59:59.000Z

54

The Diurnal Cycle of the Boundary Layer, Convection, Clouds, and Surface Radiation in a Coastal Monsoon Environment (Darwin, Australia)  

E-Print Network (OSTI)

Monsoon Environment (Darwin, Australia) PETER T. MAY Centre for Australian Weather and Climate Research variability of convection in a coastal monsoonal environment examining the interaction of convective rain Measurement (ARM) program. Both active monsoonal and large-scale suppressed (buildup and break) conditions

Protat, Alain

55

Measurement and Modeling of Solar and PV Output Variability: Preprint  

DOE Green Energy (OSTI)

This paper seeks to understand what temporal and spatial scales of variability in global horizontal radiation are important to a PV plants and what measurements are needed to be able to characterize them. As solar radiation measuring instruments are point receivers it is important to understand how those measurements translate to energy received over a larger spatial extent. Also of importance is the temporal natural of variability over large spatial areas. In this research we use high temporal and spatial resolution measurements from multiple sensors at a site in Hawaii to create solar radiation fields at various spatial and temporal scales. Five interpolation schemes were considered and the high resolution solar fields were converted to power production for a PV power plant. It was found that the interpolation schemes are robust and create ramp distributions close to what would be computed if the average solar radiation field was used. We also investigated the possibility of using time averaged solar data from 1 sensor to recreate the ramp distribution from the 17 sensors. It was found that the ramping distribution from using appropriately time averaged data from 1 sensor can reasonably match the distribution created using the 17 sensor network.

Sengupta, M.

2011-04-01T23:59:59.000Z

56

Measurement and Modeling of Solar and PV Output Variability  

Science Conference Proceedings (OSTI)

This paper seeks to understand what temporal and spatial scales of variability in global horizontal radiation are important to a PV plants and what measurements are needed to be able to characterize them. As solar radiation measuring instruments are point receivers it is important to understand how those measurements translate to energy received over a larger spatial extent. Also of importance is the temporal natural of variability over large spatial areas. In this research we use high temporal and spatial resolution measurements from multiple sensors at a site in Hawaii to create solar radiation fields at various spatial and temporal scales. Five interpolation schemes were considered and the high resolution solar fields were converted to power production for a PV power plant. It was found that the interpolation schemes are robust and create ramp distributions close to what would be computed if the average solar radiation field was used. We also investigated the possibility of using time averaged solar data from 1 sensor to recreate the ramp distribution from the 17 sensors. It was found that the ramping distribution from using appropriately time averaged data from 1 sensor can reasonably match the distribution created using the 17 sensor network.

Sengupta, M.

2011-01-01T23:59:59.000Z

57

Measurement and Modeling of Solar and PV Output Variability: Preprint  

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

Measurement and Modeling of Measurement and Modeling of Solar and PV Output Variability Preprint M. Sengupta To be presented at SOLAR 2011 Raleigh, North Carolina May 17-21, 2011 Conference Paper NREL/CP-5500-51105 April 2011 NOTICE The submitted manuscript has been offered by an employee of the Alliance for Sustainable Energy, LLC (Alliance), a contractor of the US Government under Contract No. DE-AC36-08GO28308. Accordingly, the US Government and Alliance retain a nonexclusive royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for US Government purposes. This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty,

58

Acoustic Doppler Velocimeter Flow Measurement from an Autonomous Underwater Vehicle with Applications to Deep Ocean Convection  

Science Conference Proceedings (OSTI)

The authors present a new modality for direct measurement of ocean flow, achieved by combining the resolution and precision of an acoustic Doppler velocimeter with the mobility of an autonomous underwater vehicle. To obtain useful measurements, ...

Yanwu Zhang; Knut Streitlien; James G. Bellingham; Arthur B. Baggeroer

2001-12-01T23:59:59.000Z

59

High-Resolution Simulation of Mean Convection and Its Intraseasonal Variability over the Tropics in the MRI/JMA 20-km Mesh AGCM  

Science Conference Proceedings (OSTI)

Tropical mean convection and its organization on different spatiotemporal scales in a simulation using the Meteorological Research Institute/Japan Meteorological Agency (MRI/JMA) global atmospheric general circulation model (AGCM) at 20-km ...

K. Rajendran; A. Kitoh; R. Mizuta; S. Sajani; T. Nakazawa

2008-08-01T23:59:59.000Z

60

Measurement of Water Vapor Flux Profiles in the Convective Boundary Layer with Lidar and Radar-RASS  

Science Conference Proceedings (OSTI)

A remote-sensing method to retrieve vertical profiles of water vapor flux in the convective boundary layer by using a differential absorption lidar and a radar-radio acoustic sounding system is described. The system's height range presently ...

Christoph Senff; Jens Bösenberg; Gerhard Peters

1994-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "measurement variable convection" 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

SCOUT-O3/ACTIVE: High-altitude Aircraft Measurements around Deep Tropical Convection  

Science Conference Proceedings (OSTI)

During November and December 2005, two consortia of mainly European groups conducted an aircraft campaign in Darwin, Australia, to measure the composition of the tropical upper-troposphere and tropopause regions, between 12 and 20 km, in order to ...

G. Vaughan; K. Bower; C. Schiller; A. R. MacKenzie; T. Peter; H. Schlager; N. R. P. Harris; P. T. May

2008-05-01T23:59:59.000Z

62

The Michigan Prandtl System: An Instrument for Accurate Pressure Measurements in Convective Vortices  

Science Conference Proceedings (OSTI)

This article describes a Prandtl tube system developed at the University of Michigan to measure the static pressure, the total (or stagnation) pressure, and the velocity in flows whose direction and intensity change rapidly. The ever-changing wind ...

Douglas G. Halleaux; Jeffery M. Sussman; Nilton O. Rennó

2013-10-01T23:59:59.000Z

63

Convective Boundary Layer Height Measurement with Wind Profilers and Comparison to Cloud Base  

Science Conference Proceedings (OSTI)

The depth of the atmospheric boundary layer is of interest in several different areas, such as chemistry, pollutant studies, and global modeling. In this research the authors describe and compare several different measurements of boundary layer ...

Alison W. Grimsdell; Wayne M. Angevine

1998-12-01T23:59:59.000Z

64

Aspects of Convective Boundary Layer Turbulence Measured by a Dual-Doppler Lidar System  

Science Conference Proceedings (OSTI)

Special designed dual-Doppler setups can be used to retrieve simultaneous measurements of two wind components with high temporal resolution in several heights throughout the atmospheric boundary layer. During a field campaign in summer 2011, ...

Luisa Röhner; Katja Träumner

2013-09-01T23:59:59.000Z

65

Multiparameter Radar Measurements in Colorado Convective Storms. Part I: Graupel Melting Studies  

Science Conference Proceedings (OSTI)

This paper presents an analysis of coordinated measurements taken by the NCAR CP-2 radar and the Wyoming King Air aircraft flown by NCAR during the May Polarization Experiment, which was held new Boulder, Colorado. A key feature of this paper is ...

V. N. Bringi; R. M. Rasmussen; J. Vivekanandan

1986-11-01T23:59:59.000Z

66

Propagating and Standing Components of the Intraseasonal Oscillationin Tropical Convection  

Science Conference Proceedings (OSTI)

Two questions related to the intraseasonal variability of tropical convection and circulation remain controversial. 1) To what degree is the convective component of the Madden–Julian oscillation (MJO) a standing oscillation? 2) Is the eastward ...

Chidong Zhang; Harry H. Hendon

1997-03-01T23:59:59.000Z

67

Thermodynamic Properties of Mesoscale Convective Systems Observed during BAMEX  

Science Conference Proceedings (OSTI)

Dropsonde observations from the Bow Echo and Mesoscale Convective Vortex Experiment (BAMEX) are used to document the spatiotemporal variability of temperature, moisture, and wind within mesoscale convective systems (MCSs). Onion-type sounding ...

James Correia Jr.; Raymond W. Arritt

2008-11-01T23:59:59.000Z

68

Sensitivity of Monthly Convective Precipitation to Environmental Conditions  

Science Conference Proceedings (OSTI)

Identifying dynamical and physical mechanisms controlling variability of convective precipitation is critical for predicting intraseasonal and longer-term changes in warm-season precipitation and convectively driven large-scale circulations. On a ...

Boksoon Myoung; John W. Nielsen-Gammon

2010-01-01T23:59:59.000Z

69

Detection and measurement of Post-Rosenbluth convective instability in MFTF with a hybrid CO/sub 2/ laser--heterodyne diagnostic system  

SciTech Connect

To measure and classify the Post-Rosenbluth convective loss-cone instability in MFTF, we propose to use a CO/sub 2/ laser consisting of a TEA-pulsed section and a low pressure CW section, together with a light mixing receiver. Calculations show that this system offers sufficient power and sensitivity to detect instability throughout the range from strong coherent light scattering to weak incoherent scattering when the instability is eliminated.

Peratt, A.L.

1977-10-05T23:59:59.000Z

70

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

71

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

72

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

73

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

74

Variability in Measured Space Temperatures in 60 Homes  

SciTech Connect

This report discusses the observed variability in indoor space temperature in a set of 60 homes located in Florida, New York, Oregon, and Washington. Temperature data were collected at 15-minute intervals for an entire year, including living room, master bedroom, and outdoor air temperature (Arena, et. al). The data were examined to establish the average living room temperature for the set of homes for the heating and cooling seasons, the variability of living room temperature depending on climate, and the variability of indoor space temperature within the homes. The accuracy of software-based energy analysis depends on the accuracy of input values. Thermostat set point is one of the most influential inputs for building energy simulation. Several industry standards exist that recommend differing default thermostat settings for heating and cooling seasons. These standards were compared to the values calculated for this analysis. The data examined for this report show that there is a definite difference between the climates and that the data do not agree well with any particular standard.

Roberts, D.; Lay, K.

2013-03-01T23:59:59.000Z

75

A Variable Sky-View Platform for the Measurement of Ultraviolet Radiation  

Science Conference Proceedings (OSTI)

One of the more difficult tasks confronting atmospheric researchers today is the acquisition of long-term radiometric measurements that encapsulate variability in the sky hemisphere as well as time. High quality spatial measurements would allow ...

Christopher Kuchinke; Manuel Nunez

2003-08-01T23:59:59.000Z

76

On Gaussian Random Measures Generated by Empirical Distributions of Independent Random Variables  

E-Print Network (OSTI)

Normalized fluctuations of empirical measures converge to a law of a random measure if and only if the underlying random variable is purely discrete with square-root-summable probabilities. 1

unknown authors

1994-01-01T23:59:59.000Z

77

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

E-Print Network (OSTI)

The TOGA COARE experiment was carried out in the western Pacific warm pool region from November 1992 through February 1993. Data from TOGA COARE provide the opportunity for comprehensive studies of tropical oceanic convection. This study seeks to understand more about the structures of tropical mesoscale convective systems in relation to their lightning activity and cold cloud area. The properties of convective cores within the MCSs, as well as their infrared (IR) cloud top temperatures are related to cloud-to-ground lightning. IR and lightning time histories for each case are compared, and the cases ranked by mean flashes per 10000 km2. For selected cases, radar/lightning overlays and vertical profiles of maximum radar reflectivities (VPRRs) are shown in order to describe the convective structures of cells that produced lightning, and also cells that did not produce lightning. IR cloud-top temperature and lightning histories indicate the highly variable nature of the TOGA COARE MCSs. Some MCSs which have very cold cloud-top temperatures have little or no lightning. When a system did produce lightning, more flashes generally occurred during its growth phase. Overall, IR measurements seem to be a poor indicator of lightning due to the lack of a clear relationship between the size of cold cloud-top area and cloud-to-ground flashes. The overall flash rates of the TOGA COARE MCSs support previous work which showed that tropical oceanic convection has an order of magnitude less cloud-to-ground lightning than continental convection. In fact, the highest flash rate for the 13 cases was less than the weakest continental case in a Texas MCS study (Toracinta et al. 1995). Examination of individual VPRR and of all convective VPRR from the 13 cases 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 larger ice particles in the mixed phase region between 00 C and-200 C.

Restivo, Michael Edward

1995-01-01T23:59:59.000Z

78

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

79

CONVECTION REACTOR  

DOE Patents (OSTI)

An homogeneous nuclear power reactor utilizing convection circulation of the liquid fuel is proposed. The reactor has an internal heat exchanger looated in the same pressure vessel as the critical assembly, thereby eliminating necessity for handling the hot liquid fuel outside the reactor pressure vessel during normal operation. The liquid fuel used in this reactor eliminates the necessity for extensive radiolytic gas rocombination apparatus, and the reactor is resiliently pressurized and, without any movable mechanical apparatus, automatically regulates itself to the condition of criticality during moderate variations in temperature snd pressure and shuts itself down as the pressure exceeds a predetermined safe operating value.

Hammond, R.P.; King, L.D.P.

1960-03-22T23:59:59.000Z

80

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

Science Conference Proceedings (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

Note: This page contains sample records for the topic "measurement variable convection" 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

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. 14 figs.

Thorogood, R.M.

1983-12-27T23:59:59.000Z

82

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

83

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

84

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

85

Resonant Response of Deep Convection to Surface Hot Spots  

Science Conference Proceedings (OSTI)

Observations show substantial variations of the intensity of tropical and/or summertime deep convection on land that are not explained by standard measures of convective instability. One feature that distinguishes land surfaces is their ...

F. J. Robinson; S. C. Sherwood; Y. Li

2008-01-01T23:59:59.000Z

86

A Convective Line with Leading Stratiform Precipitation from BAMEX  

Science Conference Proceedings (OSTI)

On 31 May 2003, a front-fed convective line with leading stratiform precipitation (FFLS) was observed during the Bow Echo and Mesoscale Convective Vortex Experiment (BAMEX). The high-resolution BAMEX measurements provided one of the first ...

Brandon A. Storm; Matthew D. Parker; David P. Jorgensen

2007-05-01T23:59:59.000Z

87

Atmospheric Radiation Measurement (ARM) Data from Black Forest Germany for the Convective and Orographically Induced Precipitation Study (COPS)  

DOE Data Explorer (OSTI)

ARM maintains three major, permanent sites for data collection and deploys the ARM Mobile Facility to other sites as determined. In 2007 the ARM Mobile Facility (AMF) operated in the Black Forest region of Germany as part of the Convective and Orographically Induced Precipitation Study (COPS). Scientists studied rainfall resulting from atmospheric uplift (convection) in mountainous terrain, otherwise known as orographic precipitation. This was part of a six -year duration of the German Quantitative Precipitation Forecasting (QPF) Program. See the COPS home at https://www.uni-hohenheim.de/spp-iop/index.htm and the QPF homepage at http://www.meteo.uni-bonn.de/projekte/SPPMeteo/ Information obtained during COPS will not only aid regional weather forecasts to help protect people and land, but will also help scientists determine how clouds affect the climate in complex terrain around the world. Because of its relevance to society, COPS has been endorsed as a Research and Development Project by the World Weather Research Program. This program was established by the World Meteorological Organization to develop improved and cost-effective forecasting techniques, with an emphasis on high-impact weather. [Taken from http://www.arm.gov/sites/amf/blackforest/] A large collection of data plots based on data streams from specific instruments used at Black Forest are available via a link from ARM's Black Forest site information page. Users will be requested to create a password, but the plots and the data files in the ARM Archive are free for viewing and downloading. The URL to go directly to the ARM Archive, bypassing the information pages, is http://www.archive.arm.gov/ The Office of Biological and Environmental Research in DOE's Office of Science is responsible for the ARM Program. The ARM Archive physically resides at the Oak Ridge National Laboratory.

88

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

89

Measurement and QCD analysis of event shape variables in deep-inelastic electron-proton collisions at HERA  

E-Print Network (OSTI)

Measurement and QCD analysis of event shape variables in deep-inelastic electron-proton collisions at HERA

Kluge, T

2004-01-01T23:59:59.000Z

90

Assimilation of Simulated Polarimetric Radar Data for a Convective Storm Using the Ensemble Kalman Filter. Part I: Observation Operators for Reflectivity and Polarimetric Variables  

Science Conference Proceedings (OSTI)

A radar simulator for polarimetric radar variables, including reflectivities at horizontal and vertical polarizations, the differential reflectivity, and the specific differential phase, has been developed. This simulator serves as a test bed for ...

Youngsun Jung; Guifu Zhang; Ming Xue

2008-06-01T23:59:59.000Z

91

Observations of Vertical Wind Shear Heterogeneity in Convective Boundary Layers  

Science Conference Proceedings (OSTI)

Dual-Doppler wind syntheses from mobile radar observations obtained during the International H2O Project document some of the spatial variability of vertical wind profiles in convective boundary layers. Much of the variability of popular ...

Paul Markowski; Yvette Richardson

2007-03-01T23:59:59.000Z

92

The 30–60-Day Convection Seesaw between the Tropical Indian and Western Pacific Oceans  

Science Conference Proceedings (OSTI)

The tropical Indian and western Pacific oceans are two prominent action centers for tropical 30–60-day convective variability. When convection is enhanced over the equatorial Indian Ocean, the tropical western Pacific often experiences an ...

Baozhen Zhu; Bin Wang

1993-01-01T23:59:59.000Z

93

The Vertical Structure of TOGA COARE Convection. Part II: Modulating Influences and Implications for Diabatic Heating  

Science Conference Proceedings (OSTI)

The temporal variability of western Pacific warm pool convection, especially its vertical structure, is examined in this study. Distributions of convective echo top heights and 30-dBZ contour heights have been produced from shipboard radar data ...

Charlotte A. DeMott; Steven A. Rutledge

1998-09-01T23:59:59.000Z

94

Using the Stochastic Multicloud Model to Improve Tropical Convective Parameterization: A Paradigm Example  

Science Conference Proceedings (OSTI)

Despite recent advances in supercomputing, current general circulation models (GCMs) poorly represent the variability associated with organized tropical convection. A stochastic multicloud convective parameterization based on three cloud types (...

Yevgeniy Frenkel; Andrew J. Majda; Boualem Khouider

2012-03-01T23:59:59.000Z

95

Disaggregating measurement uncertainty from population variability and Bayesian treatment of uncensored results  

Science Conference Proceedings (OSTI)

In making low-level radioactivity measurements of populations, it is commonly observed that a substantial portion of net results are negative. Furthermore, the observed variance of the measurement results arises from a combination of measurement uncertainty and population variability. This paper presents a method for disaggregating measurement uncertainty from population variability to produce a probability density function (PDF) of possibly true results. To do this, simple, justifiable, and reasonable assumptions are made about the relationship of the measurements to the measurands (the 'true values'). The measurements are assumed to be unbiased, that is, that their average value is the average of the measurands. Using traditional estimates of each measurement's uncertainty to disaggregate population variability from measurement uncertainty, a PDF of measurands for the population is produced. Then, using Bayes's theorem, the same assumptions, and all the data from the population of individuals, a prior PDF is computed for each individual's measurand. These PDFs are non-negative, and their average is equal to the average of the measurement results for the population. The uncertainty in these Bayesian posterior PDFs is all Berkson with no remaining classical component. The methods are applied to baseline bioassay data from the Hanford site. The data include 90Sr urinalysis measurements on 128 people, 137Cs in vivo measurements on 5,337 people, and 239Pu urinalysis measurements on 3,270 people. The method produces excellent results for the 90Sr and 137Cs measurements, since there are nonzero concentrations of these global fallout radionuclides in people who have not been occupationally exposed. The method does not work for the 239Pu measurements in non-occupationally exposed people because the population average is essentially zero.

Strom, Daniel J.; Joyce, Kevin E.; Maclellan, Jay A.; Watson, David J.; Lynch, Timothy P.; Antonio, Cheryl L.; Birchall, Alan; Anderson, Kevin K.; Zharov, Peter

2012-04-17T23:59:59.000Z

96

Severe Convective Wind Environments  

Science Conference Proceedings (OSTI)

Nontornadic thunderstorm winds from long-lived, widespread convective windstorms can have a tremendous impact on human lives and property. To examine environments that support damaging wind producing convection, sounding parameters from Rapid ...

Evan L. Kuchera; Matthew D. Parker

2006-08-01T23:59:59.000Z

97

Measuring Upper Ocean Variability from an Array of Surface Moorings in the Subtropical Convergence Zone  

Science Conference Proceedings (OSTI)

Measurements of upper ocean variability were made in the subtropical convergence zone southwest of Bermuda from an array of five surface moorings set with spacings of 16 to 53 km. The intent was to observe oceanic fronts and to quantify the ...

Robert A. Weller; Daniel L. Rudnick; Nancy J. Pennington; Richard P. Trask; James R. Valdes

1990-02-01T23:59:59.000Z

98

An Airborne Precipitation Cloud Particle Charge Measurement Device and Analysis System  

Science Conference Proceedings (OSTI)

A system is described for measurement and analysis of precipitation particle charge from an aircraft in the highly variable and harsh environment of a convective cloud. A compromise, practical instrument design enables particle charge and sign to ...

C. P. R. Saunders; R. L. Pitter; B. A. Gardiner; J. Hallett

1988-02-01T23:59:59.000Z

99

Doppler Radar Sampling Limitations in Convective Storms  

Science Conference Proceedings (OSTI)

Vertical air motion data from a T-28 aircraft were filtered and sampled to simulate Doppler radar measurements. The results suggest that multiple Doppler radar analyses are subject to potentially large spatial aliasing errors in deep convection ...

R. E. Carbone; M. J. Carpenter; C. D. Burghart

1985-09-01T23:59:59.000Z

100

Inferring Convective Weather Characteristics with Geostationary High Spectral Resolution IR Window Measurements: A Look into the Future  

Science Conference Proceedings (OSTI)

A high spectral resolution geostationary sounder can make spectrally detailed measurements of the infrared spectrum at high temporal resolution, which provides unique information about the lower-tropospheric temperature and moisture structure. ...

Justin M. Sieglaff; Timothy J. Schmit; W. Paul Menzel; Steven A. Ackerman

2009-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "measurement variable convection" 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

Error Sources and Accuracy of Vertical Velocities Computed from Multiple-Doppler Radar Measurements in Deep Convective Storms  

Science Conference Proceedings (OSTI)

Actual data are used in one case to investigate the nature and source of vertical velocity errors resulting from analyses of multiple-Doppler radar measurements. Consistent with earlier analytical works, larger errors are found than would be ...

Stephan P. Nelson; Rodger A. Brown

1987-03-01T23:59:59.000Z

102

Liquid convective diodes  

DOE Green Energy (OSTI)

Liquid convective diodes are analyzed by experiments and theory. The experiments include flow visualization and temperature measurements. The dynamic behavior of a diode is analyzed and explained. Performance of three diodes of different designs that were installed in a test cell this past winter showed an average 50% thermal efficiency over a three-month period. If only the performance of the most efficient diode among the three is considered, it is expected that this figure may be increased to 60% or possibly 65% with some design improvements. A simple analytical model, which was developed earlier, is discussed. A comparison of reservoir temperatures from one of the test cell diodes with predicted temperatures from the model showed excellent agreement. The good agreement indicates that the model contains the elements that are necessary to accurately predict site-specific diode performance.

Jones, G.F.

1984-01-01T23:59:59.000Z

103

The Relationship between Tropical Cyclone Intensity Change and the Strength of Inner-Core Convection  

Science Conference Proceedings (OSTI)

Convective intensity proxies measured by the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI), Precipitation Radar (PR), and Visible and Infrared Scanner (VIRS) are used to assess the relationship between intense convection in the ...

Haiyan Jiang

2012-04-01T23:59:59.000Z

104

Forecasting the Maintenance of Quasi-Linear Mesoscale Convective Systems  

Science Conference Proceedings (OSTI)

The problem of forecasting the maintenance of mesoscale convective systems (MCSs) is investigated through an examination of observed proximity soundings. Furthermore, environmental variables that are statistically different between mature and ...

Michael C. Coniglio; Harold E. Brooks; Steven J. Weiss; Stephen F. Corfidi

2007-06-01T23:59:59.000Z

105

Two-Zone Convective Scaling of Diffusion in Complex Terrain  

Science Conference Proceedings (OSTI)

A “two-zone” convective scaling equation is developed that allows for a step change in scaling parameters. The results of the Lompoc Valley Diffusion Experiment, conducted at coastal site in California under variable cloud cover, are compared to ...

C. E. Skupniewicz

1994-05-01T23:59:59.000Z

106

The Diurnal Cycle of the Boundary Layer, Convection, Clouds, and Surface Radiation in a Coastal Monsoon Environment (Darwin, Australia)  

Science Conference Proceedings (OSTI)

The diurnal variation of convection and associated cloud and radiative properties remains a significant issue in global NWP and climate models. This study analyzes observed diurnal variability of convection in a coastal monsoonal environment ...

Peter T. May; Charles N. Long; Alain Protat

2012-08-01T23:59:59.000Z

107

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

108

Abstract--Heart rate variability (HRV) is frequently used to measure autonomic nervous system (ANS) activity. However,  

E-Print Network (OSTI)

1 of 4 Abstract--Heart rate variability (HRV) is frequently used to measure autonomic nervous frequency (HF) ratio with little change in mean heart rate. Results suggest that nicotine affects both components may yield erroneous results. Keywords--Autonomic regulation, heart rate variability, Lomb

109

Radar Analysis of a Tropical Convective Boundary Layer with Shallow Cumulus Clouds  

Science Conference Proceedings (OSTI)

A situation of fair weather cloudy convection is examined using a dual Doppler radar, environmental measurements and cloud photogrammetry. The convective layer is characterized by the interaction between the northward monsoon wind at low levels ...

Laurence Eymard

1984-04-01T23:59:59.000Z

110

Characteristics of Vertical Velocity Cores in Different Convective Systems Observed over Gadanki, India  

Science Conference Proceedings (OSTI)

The Indian mesosphere–stratosphere–troposphere (MST) radar measurements during the passage of 60 convective systems are used to study the vertical air velocity (w) characteristics of tropical convection. The up- and downdraft cores and various ...

K. N. Uma; T. Narayana Rao

2009-03-01T23:59:59.000Z

111

Polarization diversity for millimeter space-borne Doppler radars: an answer for observing deep convection?  

Science Conference Proceedings (OSTI)

Spaceborne Doppler radars have the potential to provide key missing observations of convective vertical air motions especially over the tropical oceans. Such measurements can improve our understanding of the role of tropical convection in vertical ...

Alessandro Battaglia; Simone Tanelli; Pavlos Kollias

112

Restratification after Deep Convection  

Science Conference Proceedings (OSTI)

An important, yet poorly understood, aspect of the water mass transformation process in the ocean is the manner in which the convected fluid, once formed, is accommodated and drawn into the general circulation. Following “violent mixing” in the ...

Helen Jones; John Marshall

1997-10-01T23:59:59.000Z

113

Global Characteristics of Ocean Variability Estimated from Regional TOPEX/POSEIDON Altimeter Measurements  

Science Conference Proceedings (OSTI)

Three years of altimetric data from the TOPEX/POSEIDON spacecraft have been used to study characteristics of eddy variability over the World Ocean. The nature of the variability and its spatial structure are characterized in terms of the ...

Detlef Stammer

1997-08-01T23:59:59.000Z

114

Processes of Hydrometeor Development in Oklahoma Convective Clouds  

Science Conference Proceedings (OSTI)

This study employs in situ measurements to examine cloud conditions in which hydrometeors develop in mature Oklahoma convective clouds and to develop hypotheses as to how they formed. The measurements were made from penetrations on six days using ...

Andrew J. Heymsfield; Mark R. Hjelmfelt

1984-10-01T23:59:59.000Z

115

Deep Convective Rotational Solitary Waves and Mesoscale Convective Complexes  

Science Conference Proceedings (OSTI)

As an extension of CCI (conditional convective instability) theory, three-dimensional, deep and steady convective waves in a barotropic basic flow with an embedded moist zone were studied via perturbation methods. The basic state is assumed to be ...

Qin Xu

1987-06-01T23:59:59.000Z

116

The Convective Storm Initiation Project  

Science Conference Proceedings (OSTI)

The Convective Storm Initiation Project (CSIP) is an international project to understand precisely where, when, and how convective clouds form and develop into showers in the mainly maritime environment of southern England. A major aim of CSIP is ...

Keith A. Browning; Cyril J. Morcrette; John Nicol; Alan M. Blyth; Lindsay J. Bennett; Barbara J. Brooks; John Marsham; Stephan D. Mobbs; Douglas J. Parker; Felicity Perry; Peter A. Clark; Sue P. Ballard; Mark A. Dixon; Richard M. Forbes; Humphrey W. Lean; Zhihong Li; Nigel M. Roberts; Ulrich Corsmeier; Christian Barthlott; Bernhard Deny; Norbert Kalthoff; Samiro Khodayar; Martin Kohler; Christoph Kottmeier; Stephan Kraut; Michael Kunz; Jürgen Lenfant; Andreas Wieser; Judith L. Agnew; Dave Bamber; James McGregor; Karl M. Beswick; Malcolm D. Gray; Emily Norton; Hugo M. A. Ricketts; Andrew Russell; Geraint Vaughan; Ann R. Webb; Mark Bitter; Thomas Feuerle; Rolf Hankers; Helmut Schulz; Karen E. Bozier; Chris G. Collier; Fay Davies; Catherine Gaffard; Tim J. Hewison; Darcy N. Ladd; Elizabeth C. Slack; Joe Waight; Markus Ramatschi; David P. Wareing; Robert J. Watson

2007-12-01T23:59:59.000Z

117

Convection Patterns in a Pond  

Science Conference Proceedings (OSTI)

Unusual convection patterns were observed in snow-slush an a pond in Seattle, Wash., during January 1980 and again during February 1981. The patterns are reminiscent of spoke-type convection discovered experimentally by Busse and Whitehead (1974)...

Kristina B. Katsaros

1981-10-01T23:59:59.000Z

118

NATURAL CONVECTION IN ROOM GEOMETRIES  

E-Print Network (OSTI)

that convective heat transfer processes are These computer~vective .part of the heat transfer process ? elng studled*of convect i ve heat transfer processes, the behavior of a

Gadgil, A.

2008-01-01T23:59:59.000Z

119

5, 1102911054, 2005 Convective gravity  

E-Print Network (OSTI)

ACPD 5, 11029­11054, 2005 Convective gravity waves at mid-latitudes Y. G. Choi et al. Title Page Discussions Wind-profiler observations of gravity waves produced by convection at mid-latitudes Y. G. Choi1­11054, 2005 Convective gravity waves at mid-latitudes Y. G. Choi et al. Title Page Abstract Introduction

Paris-Sud XI, Université de

120

Measurement of GCM Skill in Predicting Variables Relevant for Hydroclimatological Assessments  

Science Conference Proceedings (OSTI)

Simulations from general circulation models are now being used for a variety of studies and purposes. With up to 23 different GCMs now available, it is desirable to determine whether a specific variable from a particular model is representative ...

Fiona Johnson; Ashish Sharma

2009-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "measurement variable convection" 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

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.

122

The Diurnal Cycle of the Boundary Layer, Convection, Clouds, and Surface Radiation in a Coastal Monsoon Environment (Darwin Australia)  

SciTech Connect

The diurnal variation of convection and associated cloud and radiative properties remains a significant issue in global NWP and climate models. This study analyzes observed diurnal variability of convection in a coastal monsoonal environment examining the interaction of convective rain clouds, their associated cloud properties, and the impact on the surface radiation and corresponding boundary layer structure during periods where convection is suppressed or active on the large scale. The analysis uses data from the Tropical Warm Pool International Cloud Experiment (TWP-ICE) as well as routine measurements from the Australian Bureau of Meteorology and the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) program. Both active monsoonal and large-scale suppressed (buildup and break) conditions are examined and demonstrate that the diurnal variation of rainfall is much larger during the break periods and the spatial distribution of rainfall is very different between the monsoon and break regimes. During the active monsoon the total net radiative input to the surface is decreased by more than 3 times the amount than during the break regime - this total radiative cloud forcing is found to be dominated by the shortwave (SW) cloud effects because of the much larger optical thicknesses and persistence of long-lasting anvils and cirrus cloud decks associated with the monsoon regime. These differences in monsoon versus break surface radiative energy contribute to low-level air temperature differences in the boundary layer over the land surfaces.

May, Peter T.; Long, Charles N.; Protat, Alain

2012-08-01T23:59:59.000Z

123

NATURAL CONVECTION IN PASSIVE SOLAR BUILDINGS: EXPERIMENTS, ANALYSIS AND RESULTS  

E-Print Network (OSTI)

convection process and calculate convective heat transferthat convective heat transfer processes are highly dependentheat transfer process being studied* and

Gadgil, Ashok; Bauman, Fred; Kammerud, Ronald

2008-01-01T23:59:59.000Z

124

Damage measurements on the NWTC direct-drive, variable-speed test bed  

SciTech Connect

The NWTC (National Wind Technology Center) Variable-Speed Test Bed turbine is a three-bladed, 10-meter, downwind machine that can be run in either fixed-speed or variable-speed mode. In the variable-speed mode, the generator torque is regulated, using a discrete-stepped load bank to maximize the turbine`s power coefficient. At rated power, a second control loop that uses blade pitch to maintain rotor speed essentially as before, i.e., using the load bank to maintain either generator power or (optionally) generator torque. In this paper, the authors will use this turbine to study the effect of variable-speed operation on blade damage. Using time-series data obtained from blade flap and edge strain gauges, the load spectrum for the turbine is developed using rainflow counting techniques. Miner`s rule is then used to determine the damage rates for variable-speed and fixed-speed operation. The results illustrate that the controller algorithm used with this turbine introduces relatively large load cycles into the blade that significantly reduce its service lifetime, while power production is only marginally increased.

Sutherland, H.J. [Sandia National Lab., Albuquerque, NM (United States); Carlin, P.W. [National Renewable Energy Lab., Golden, CO (United States)

1998-12-31T23:59:59.000Z

125

Convective Storm Initiation in a Moist Tropical Environment  

Science Conference Proceedings (OSTI)

Radar and satellite data from the Tropical Rainfall Measuring Mission–Large-Scale Biosphere–Atmosphere (TRMM–LBA) project have been examined to determine causes for convective storm initiation in the southwest Amazon region. The locations and ...

Maria Andrea Lima; James W. Wilson

2008-06-01T23:59:59.000Z

126

The Tropical Convective Spectrum. Part I: Archetypal Vertical Structures  

Science Conference Proceedings (OSTI)

A taxonomy of tropical convective and stratiform vertical structures is constructed through cluster analysis of 3 yr of Tropical Rainfall Measuring Mission (TRMM) “warm-season” (surface temperature greater than 10°C) precipitation radar (PR) ...

Dennis J. Boccippio; Walter A. Petersen; Daniel J. Cecil

2005-07-01T23:59:59.000Z

127

Physical Characterization of Tropical Oceanic Convection Observed in KWAJEX  

Science Conference Proceedings (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

128

Sampling Characteristics from Isobaric Floats in a Convective Eddy Field  

Science Conference Proceedings (OSTI)

During the recent Labrador Sea Deep Convection Experiment, numerous isobaric floats were deployed. Interpretation of the quasi-Lagrangian measurements from these floats requires an understanding of any biases that may be introduced by the ...

Sonya Legg; James C. McWilliams

2002-02-01T23:59:59.000Z

129

Diabatic Divergence Profiles in Western Pacific Mesoscale Convective Systems  

Science Conference Proceedings (OSTI)

Heating in the atmosphere can be expressed as diabatic divergence ?d, which is nearly equal to the actual horizontal divergence ? in tropical convection. High-quality ? profile measurements from airborne Doppler radar “purls” in ten mesoscale ...

Brian E. Mapes; Robert A. Houze Jr.

1995-05-01T23:59:59.000Z

130

A Stochastic Model for the Transition to Strong Convection  

Science Conference Proceedings (OSTI)

A simple stochastic model is designed and analyzed in order to further understand the transition to strong convection. The transition has been characterized recently in observational data by an array of statistical measures, including (i) a sharp ...

Samuel N. Stechmann; J. David Neelin

2011-12-01T23:59:59.000Z

131

The Manifestation of the Madden–Julian Oscillation in Global Deep Convection and in the Schumann Resonance Intensity  

Science Conference Proceedings (OSTI)

This study determines the relationship between intraseasonal oscillations observed in two independent measures of global lightning activity: a global mean convective index (a proxy for deep convection) derived from the Goddard Television Infrared ...

E. Anyamba; E. Williams; J. Susskind; A. Fraser-Smith; M. Fullekrug

2000-04-01T23:59:59.000Z

132

Characteristics of Summer Convective Systems Initiated over the Tibetan Plateau. Part I: Origin, Track, Development, and Precipitation  

Science Conference Proceedings (OSTI)

Summer convective systems (CSs) initiated over the Tibetan Plateau identified by the International Satellite Cloud Climatology Project (ISCCP) deep convection database and associated Tropical Rainfall Measuring Mission (TRMM) precipitation for ...

Li Yaodong; Wang Yun; Song Yang; Hu Liang; Gao Shouting; Rong Fu

2008-10-01T23:59:59.000Z

133

Measure Guideline: Replacing Single-Speed Pool Pumps with Variable Speed Pumps for Energy Savings  

Science Conference Proceedings (OSTI)

The report evaluates potential energy savings by replacing traditional single-speed pool pumps with variable speed pool pumps, and provide a basic cost comparison between continued uses of traditional pumps verses new pumps. A simple step-by-step process for inspecting the pool area and installing a new pool pump follows.

Hunt, A.; Easley, S.

2012-05-01T23:59:59.000Z

134

Control and Monitoring Instrumentation for the Continuous Measurement of Atmospheric CO2 and Meteorological Variables  

Science Conference Proceedings (OSTI)

The NOAA/GMCC program was chartered to monitor the trends in those atmospheric constituents that can cause climate change. A four-observatory network was established, and a 15-year database has resulted for selected variables. At the inception, a ...

G. A. Herbert; E. R. Green; J. M. Harris; G. L. Koenig; S. J. Roughton; K. W. Thaut

1986-09-01T23:59:59.000Z

135

Angular diameter measurements of evolved variables by lunar occultations at 2.2 and 3.8 micron  

E-Print Network (OSTI)

We report the angular diameters of two Mira variables (U Ari and Z Sco), three semiregular (SR) and irregular variables (SW Vir, eta Gem and mu Gem) and a supergiant SR variable (TV Gem) by lunar occultation observations in the near-IR broad K-band (2.2 micron). Lunar occultations of eta Gem and mu Gem were also observed for the first time simultaneously in both the K and L' bands, yielding angular diameters at 2.2 and 3.8 micron. Effective temperatures and linear radii are also derived for all the observed sources and compared with earlier measurements. The mode of pulsation of both Mira and SR sources in our sample is discussed.

Soumen Mondal; T. Chandrasekhar

2005-04-14T23:59:59.000Z

136

Angular diameter measurements of evolved variables by lunar occultations at 2.2 and 3.8 micron  

E-Print Network (OSTI)

We report the angular diameters of two Mira variables (U Ari and Z Sco), three semiregular (SR) and irregular variables (SW Vir, eta Gem and mu Gem) and a supergiant SR variable (TV Gem) by lunar occultation observations in the near-IR broad K-band (2.2 micron). Lunar occultations of eta Gem and mu Gem were also observed for the first time simultaneously in both the K and L' bands, yielding angular diameters at 2.2 and 3.8 micron. Effective temperatures and linear radii are also derived for all the observed sources and compared with earlier measurements. The mode of pulsation of both Mira and SR sources in our sample is discussed.

Mondal, S A; Mondal, Soumen

2005-01-01T23:59:59.000Z

137

Interannual Variability of Deep-Water Formation in the Northwestern Mediterranean  

Science Conference Proceedings (OSTI)

In the Gulf of Lions, observations of deep convection have been sporadically carried out over the past three decades, showing significant interannual variability of convection activity. As long time series of meteorological observations of the ...

C. Mertens; F. Schott

1998-07-01T23:59:59.000Z

138

Convective Modifications of a Geostrophic Eddy Field  

Science Conference Proceedings (OSTI)

Ocean convection often occurs in regions of mesoscale eddy activity, where convective mixing and geostrophic eddy dynamics interact. The authors examine the interactions between a group of geostrophic eddies and convective mixing induced by ...

Sonya Legg; James C. McWilliams

2001-04-01T23:59:59.000Z

139

Tropical Convection on 7–21-Day Timescales over the Western Pacific  

Science Conference Proceedings (OSTI)

Evidence is presented to demonstrate that the oscillations of convection on 7–21-day timescales are an important component of the intraseasonal variability over the region spanning the equatorial western Pacific to the subtropical South Pacific. ...

Jon M. Schrage; Dayton G. Vincent

1996-03-01T23:59:59.000Z

140

Verification of Convection-Allowing WRF Model Forecasts of the Planetary Boundary Layer Using Sounding Observations  

Science Conference Proceedings (OSTI)

This study evaluates forecasts of thermodynamic variables from five convection-allowing configurations of the Weather Research and Forecasting Model (WRF) with the Advanced Research core (WRF-ARW). The forecasts vary only in their planetary ...

Michael C. Coniglio; James Correia Jr.; Patrick T. Marsh; Fanyou Kong

2013-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "measurement variable convection" 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

A Sensitivity Study of Convective Cloud Formation by Vegetation Forcing with Different Atmospheric Conditions  

Science Conference Proceedings (OSTI)

Variable vegetation cover is a possible trigger for convection, especially in semiarid areas due to differential surface forcing. A two-dimensional numerical model with explicit cloud physics and a detailed vegetation parameterization scheme is ...

Xiaodong Hong; Martin J. Leach; Sethu Raman

1995-09-01T23:59:59.000Z

142

Vertical Transports by Plumes within the Moderately Convective Marine Atmospheric Surface Layer  

Science Conference Proceedings (OSTI)

Bursts in the kinematic vertical transports of heat and horizontal momentum in a moderately convective marine atmospheric surface layer are studied by applying the variable interval time averaging (VITA) detection method to principal components ...

Richard A. Mason; Hampton N. Shirer; Robert Wells; George S. Young

2002-04-01T23:59:59.000Z

143

Comparison of Modeled and Observed Accumulated Convective Precipitation in Mountainous and Flat Land Areas  

Science Conference Proceedings (OSTI)

Convective precipitation is the main cause of extreme rainfall events in small areas. Its primary characteristics are both large spatial and temporal variability. For this reason, the monitoring of accumulated precipitation fields (liquid and ...

Mladjen ?uri?; Dejan Janc

2011-04-01T23:59:59.000Z

144

Interactions between a Developing Mesoscale Convective System and Its Environment. Part II: Numerical Simulation  

Science Conference Proceedings (OSTI)

The 19 July 1993 mesoscale convective system (MCS), discussed in Part I, was simulated using the Regional Atmospheric Modeling System (RAMS). The model was initialized with variable physiographic and atmospheric data with the goal of reproducing ...

Jason E. Nachamkin; William R. Cotton

2000-05-01T23:59:59.000Z

145

Polarimetric Radar Observations of Convection in Northwestern Mexico during the North American Monsoon Experiment  

Science Conference Proceedings (OSTI)

The spatial and temporal variability of convection during the North American Monsoon Experiment (NAME) was examined via analysis of three-dimensional polarimetric radar data. Terrain bands were defined as the Gulf of California (over water) and ...

Timothy J. Lang; Steven A. Rutledge; Robert Cifelli

2010-12-01T23:59:59.000Z

146

Intraseasonal Variability over Tropical Africa during Northern Summer  

Science Conference Proceedings (OSTI)

The intraseasonal variability over Africa during northern summer was analyzed, using 25 years of NCEP– NCAR reanalysis and satellite data. The dominant pattern of variability was one of enhanced deep convection over the whole African monsoon ...

Adrian J. Matthews

2004-06-01T23:59:59.000Z

147

Large Diurnal Sea Surface Temperature Variability: Satellite and In Situ Measurements  

Science Conference Proceedings (OSTI)

Data from a surface mooring located in the Sargasso Sea at 34°N, 70°W between May 1982 and May 1984 were compared with satellite data to investigate large diurnal sea surface temperature changes. Mooring and satellite measurements are in ...

Lothar Stramma; Peter Cornillon; Robert A. Weller; James F. Price; Melbourne G. Briscoe

1986-05-01T23:59:59.000Z

148

Multiscale Temporal Variability of Warm-Season Precipitation over North America: Statistical Analysis of Radar Measurements  

Science Conference Proceedings (OSTI)

Directionally averaged time series of precipitation rates for eight warm seasons (1996–2003) over the continental United States derived from Next Generation Weather Radar (NEXRAD) measurements are analyzed using spectral decomposition methods. ...

Hsiao-ming Hsu; Mitchell W. Moncrieff; Wen-wen Tung; Changhai Liu

2006-09-01T23:59:59.000Z

149

Eddy Variability and Energetics from Direct Current Measurements in the Antarctic Circumpolar Current South of Australia  

Science Conference Proceedings (OSTI)

Two-year time series measurements of current velocity and temperature in the Subantarctic Front (SAF) south of Australia from 1993 to 1995 provide estimates of eddy fluxes of heat and momentum across the Antarctic Circumpolar Current (ACC) and ...

Helen E. Phillips; Stephen R. Rintoul

2000-12-01T23:59:59.000Z

150

Improving Convective Parameterization Using ARM Data  

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

Convective Parameterization Using ARM Data G. J. Zhang Center for Atmospheric Sciences Scripps Institution of Oceanography La Jolla, California Introduction Convective...

151

Synergistic Effect of coal blends on thermoplasticity evaluated using a temperature-variable dynamic viscoelastic measurement  

SciTech Connect

To maximize the conversion of low-quality coal into good coke, we investigated the thermoplasticity of various binary blends of caking coals with slightly or noncaking coals using a dynamic viscoelastic technique with a temperature-variable rheometer. Coal blend samples were prepared by mixing two coals (1:1 by weight), which were heated from room temperature to 600 C at a rate of 3-80{sup o}C/min. At the slow rate of 3{sup o}C/min, the blends had a tan {delta} that was generally lower than the calculated value, showing that a negative interaction caused a loss of thermoplasticity. In contrast, at the rapid heating rate of 80{sup o}C/min, the tan {delta} of some blends was higher than the calculated value, indicating a positive interaction that enhanced the thermoplasticity. With rapid heating, the thermoplasticity of each coal itself increased, and their thermoplastic temperature ranges widened with rapid heating. Therefore, rapid heating was effective at converting these coal blends into good cokes. Moreover, even with slow heating, when a combination of coals (Gregory:Enshu, 1:1) showing some thermoplasticity in nearly the same temperature range was blended, a desirable synergistic effect of the blend was obtained. This suggests that blending coal with an overlapping thermoplastic temperature range is important for the synergistic effect, regardless of the heating rate. 15 refs., 9 figs., 2 tabs.

Toshimasa Takanohashi; Takahiro Shishido; Ikuo Saito; Kensuke Masaki; Atsushi Dobashi; Kiyoshi Fukada [National Institute of Advanced Industrial Science and Technology, Tsukuba (Japan)

2006-12-15T23:59:59.000Z

152

Interannual variability of monsoon precipitation and local subcloud equivalent potential"! temperature#!  

E-Print Network (OSTI)

! "! Interannual variability of monsoon precipitation and local subcloud equivalent potential.hurley@yale.edu"&! "'! Keywords: monsoon, interannual variability, convective quasi-equilibrium, equivalent potential"(! temperature")! #12;! #! ABSTRACT"*! The interannual variability of monsoon precipitation is described

153

Heat Budget Calculation in the Convective Boundary Layer on a 4 × 4 Vertical versus Time Grid from Aircraft and Surface Measurements  

Science Conference Proceedings (OSTI)

Aircraft, portable tower, and radiosonde measurements from 4 August 1989 (day 68) of the First International Satellite Land Surface Climatology Project (ISLCP) Field Experiment (FIFE), over fairly flat terrain in Kansas, are used for the ...

John C. Lukas

2000-09-01T23:59:59.000Z

154

A Numerical Simulation of Convectively Induced Turbulence above Deep Convection  

Science Conference Proceedings (OSTI)

At 1034 UTC 2 September 2007, a commercial aircraft flying from Jeju, South Korea, to Osaka, Japan, at an altitude of approximately 11.2 km encountered severe turbulence above deep convection. To investigate the characteristics and generation ...

Jung-Hoon Kim; Hye-Yeong Chun

2012-06-01T23:59:59.000Z

155

Convection in pulsating stars. II. RR Lyrae convection and stability  

Science Conference Proceedings (OSTI)

Convective model envelopes of two RR Lyrae stars are constructed, one centrally located in the instability strip, and one just beyond the red edge of the stip. Steady state solutions and small amplitude oscillations are studied using a nonlinear pulsation code. We find that convection has only a small effect on the stability of the hotter model, primarily due to turbulent pressure work (net driving) in the hydrogen ionization zone. The cooler model, however, shows strong reduction in both hydrogen and helium ionization driving, which quenches the pulsation. This effect is not directly attributable to convective PdV work, but probably reflects changes in structure and phase relations in the envelope due to convection.

Stellingwerf, R.F.

1982-11-01T23:59:59.000Z

156

Idealized Mesoscale Convective System Structure and Propagation Using Convective Parameterization  

Science Conference Proceedings (OSTI)

The development and propagation of mesoscale convective systems (MCSs) was examined within the Weather Research and Forecasting (WRF) model using the Kain–Fritsch (KF) cumulus parameterization scheme and a modified version of this scheme. ...

James Correia Jr.; Raymond W. Arritt; Christopher J. Anderson

2008-07-01T23:59:59.000Z

157

Heat distribution by natural convection  

DOE Green Energy (OSTI)

Natural convection between spaces in a building can play a major role in energy transfer. Two situations are investigated: convection through a single doorway into a remote room, and a convective loop in a two-story house with a south sunspace where a north stairway serves as the return path. A doorway-sizing equation is given for the single-door case. Detailed data are given from the monitoring of airflow in one two-story house and summary data are given for five others. Observations on the nature of the airflow and design guidelines are presented.

Balcomb, J.D.; Yamaguchi, K.

1983-01-01T23:59:59.000Z

158

Uncertainty Quantification and Parameter Tuning in the CAM5 Zhang-McFarlane Convection Scheme and Impact of Improved Convection on the Global Circulation and Climate  

SciTech Connect

In this study, we applied an uncertainty quantification (UQ) technique to improve convective precipitation in the global climate model, the Community Atmosphere Model version 5 (CAM5), in which the convective and stratiform precipitation partitioning is very different from observational estimates. We examined the sensitivity of precipitation and circulation to several key parameters in the Zhang-McFarlane deep convection scheme in CAM5, using a stochastic importance-sampling algorithm that can progressively converge to optimal parameter values. The impact of improved deep convection on the global circulation and climate was subsequently evaluated. Our results show that the simulated convective precipitation is most sensitive to the parameters of the convective available potential energy consumption time scale, parcel fractional mass entrainment rate, and maximum downdraft mass flux fraction. Using the optimal parameters constrained by the observed Tropical Rainfall Measuring Mission, convective precipitation improves the simulation of convective to stratiform precipitation ratio and rain-rate spectrum remarkably. When convection is suppressed, precipitation tends to be more confined to the regions with strong atmospheric convergence. As the optimal parameters are used, positive impacts on some aspects of the atmospheric circulation and climate, including reduction of the double Intertropical Convergence Zone, improved East Asian monsoon precipitation, and improved annual cycles of the cross-equatorial jets, are found as a result of the vertical and horizontal redistribution of latent heat release from the revised parameterization. Positive impacts of the optimal parameters derived from the 2 simulations are found to transfer to the 1 simulations to some extent.

Yang, Ben; Qian, Yun; Lin, Guang; Leung, Lai-Yung R.; Rasch, Philip J.; Zhang, Guang J.; McFarlane, Sally A.; Zhao, Chun; Zhang, Yaocun; Wang, Hailong; Wang, Minghuai; Liu, Xiaohong

2013-01-25T23:59:59.000Z

159

Seasonal Variability in Clouds and Radiation at the Manus ARM Site  

SciTech Connect

The Atmospheric Radiation Measurement (ARM) program operates three climate observation stations in the tropical western Pacific region. Two of these sites, located on Manus island in Papua New Guinea and on the island republic of Nauru, have been operating for over five years. This data set provides an opportunity to examine variability in tropical cloudiness on a wide range of time scales. The focus of this study is on the annual cycle. The most obvious manifestation of the annual cycle in this region is the oscillation of monsoon convection between Asia and Australia. The impact of the annual cycle on Manus and Nauru is more subtle; however, analysis of radiation and cloud observations from the Manus and Nauru ARM sites reveals links to the annual monsoon cycle. One such link relates to the proximity of Manus to the Maritime Continent, the collection of islands separating the Pacific and Indian oceans. Convection over the large islands in the maritime continent exhibits a distinct annual cycle. Outflow from large-island convection is shown to modulate the cirrus population over Manus. During neutral or cool ENSO periods, convection over Nauru is relatively suppressed. During such periods, Nauru is shown to exhibit an annual cycle in local convective activity. During the inactive season, cirrus are often found near the tropopause over Nauru. These clouds are not formed directly by the outflow from convection. The seasonality and source of these clouds is also examined. Identifying the source of cirrus observed at Manus and Nauru is important because of the potential dependence of cirrus properties on the source of convection.

Mather, Jim H.

2005-07-01T23:59:59.000Z

160

Analysis of Convective Activity and Its Relationship to the Rainfall over the Rift Valley Lakes of East Africa during 1983–90 Using the Meteosat Infrared Channel  

Science Conference Proceedings (OSTI)

The convective activity over the Rift Valley lakes of East Africa, as deduced from cloud tops colder than a predefined threshold, is examined. Relationships between satellite-derived convective indices and rainfall measurements are also examined. ...

Mamoudou B. Ba; Sharon E. Nicholson

1998-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "measurement variable convection" 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

The Transition to Strong Convection  

Science Conference Proceedings (OSTI)

Recent work has shown that observations of tropical precipitation conform to properties associated with critical phenomena in other systems. Here some of these universal properties are used to probe the physics of tropical convection empirically, ...

J. David Neelin; Ole Peters; Katrina Hales

2009-08-01T23:59:59.000Z

162

Mesoscale Convective Complexes in Africa  

Science Conference Proceedings (OSTI)

Digitized full-disk infrared satellite imagery from the European geostationary satellite (Meteosat) for 1986 and 1987 was used to construct a climatology of mesoscale convective complexes (MCCs) in Africa One hundred ninety-five systems formed ...

Arlene G. Laing; J. Michael Fritsch

1993-08-01T23:59:59.000Z

163

Isentropic Analysis of Convective Motions  

Science Conference Proceedings (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

164

Integral Effects of Deep Convection  

Science Conference Proceedings (OSTI)

The large-scale, integral effect of convective elements (plumes) constituting an open-ocean chimney is investigated both theoretically and with a plume-resolving numerical model. The authors consider an initially homogeneous “patch” of ocean of ...

Uwe Send; John Marshall

1995-05-01T23:59:59.000Z

165

The Decay of Convective Turbulence  

Science Conference Proceedings (OSTI)

Using simulations with a large-eddy model we have studied the decay of convective turbulence in the atmospheric boundary layer when the upward surface sensible heat flux is suddenly stopped. The decay of turbulent kinetic energy and temperature ...

F. T. M. Nieuwstadt; R. A. Brost

1986-03-01T23:59:59.000Z

166

A Probabilistic Bulk Model of Coupled Mixed Layer and Convection. Part II: Shallow Convection Case  

Science Conference Proceedings (OSTI)

The probabilistic bulk convection model (PBCM) developed in a companion paper is here extended to shallow nonprecipitating convection. The PBCM unifies the clear-sky and shallow convection boundary layer regimes by obtaining mixed-layer growth, ...

Pierre Gentine; Alan K. Betts; Benjamin R. Lintner; Kirsten L. Findell; Chiel C. van Heerwaarden; Fabio D’Andrea

2013-06-01T23:59:59.000Z

167

The Impacts of Convective Parameterization and Moisture Triggering on AGCM-Simulated Convectively Coupled Equatorial Waves  

Science Conference Proceedings (OSTI)

This study examines the impacts of convective parameterization and moisture convective trigger on convectively coupled equatorial waves simulated by the Seoul National University (SNU) atmospheric general circulation model (AGCM). Three different ...

Jia-Lin Lin; Myong-In Lee; Daehyun Kim; In-Sik Kang; Dargan M. W. Frierson

2008-03-01T23:59:59.000Z

168

High-Resolution Passive Microwave Observations of Convective Systems over the Tropical Pacific Ocean  

Science Conference Proceedings (OSTI)

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

Gary McGaughey; Edward J. Zipser; Roy W. Spencer; Robbie E. Hood

1996-11-01T23:59:59.000Z

169

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

Science Conference Proceedings (OSTI)

Multiple years of measurements of tropical upper-tropospheric temperature and humidity by the Measurement of Ozone and Water Vapor by Airbus In-Service Aircraft (MOZAIC) project are analyzed in the vicinity of deep convective outflow to study the ...

Zhengzhao Johnny Luo; Dieter Kley; Richard H. Johnson; G. Y. Liu; Susanne Nawrath; Herman G. J. Smit

2012-02-01T23:59:59.000Z

170

Relating Passive 37-GHz Scattering to Radar Profiles in Strong Convection  

Science Conference Proceedings (OSTI)

Tropical Rainfall Measuring Mission (TRMM) Microwave Imager and precipitation radar measurements are examined for strong convective systems. Storms having similar values of minimum 37-GHz polarization-corrected temperature (PCT) are grouped ...

Daniel J. Cecil

2011-01-01T23:59:59.000Z

171

The MJO and Convectively Coupled Waves in a Coarse-Resolution GCM with a Simple Multicloud Parameterization  

Science Conference Proceedings (OSTI)

The adequate representation of the dominant intraseasonal and synoptic-scale variability in the tropics, characterized by the Madden–Julian oscillation (MJO) and convectively coupled waves, is still problematic in current operational general ...

Boualem Khouider; Amik St-Cyr; Andrew J. Majda; Joseph Tribbia

2011-02-01T23:59:59.000Z

172

Sensitivity of Tropical Pacific Convection to Dry Layers at Mid- to Upper Levels: Simulation and Parameterization Tests  

Science Conference Proceedings (OSTI)

Numerical forecast experiments are carried out to investigate the implications of observed moisture variability in the tropical Pacific for deep convection. The study uses a series of quasi-cloud-resolving model forecasts with a triple-nested ...

James A. Ridout

2002-12-01T23:59:59.000Z

173

Convection-Allowing and Convection-Parameterizing Ensemble Forecasts of a Mesoscale Convective Vortex and Associated Severe Weather Environment  

Science Conference Proceedings (OSTI)

An analysis of a regional severe weather outbreak that was related to a mesoscale convective vortex (MCV) is performed. The MCV-spawning mesoscale convection system (MCS) formed in northwest Kansas along the southern periphery of a large cutoff ...

Adam J. Clark; William A. Gallus Jr.; Ming Xue; Fanyou Kong

2010-08-01T23:59:59.000Z

174

ARM - Midlatitude Continental Convective Clouds  

Science Conference Proceedings (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.

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

2012-01-19T23:59:59.000Z

175

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.

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

176

Convectively Coupled Waves in a Sheared Environment  

Science Conference Proceedings (OSTI)

A linear stability analysis, about a radiative–convective equilibrium in a sheared environment, on an equatorial beta plane, for a simple multicloud model for organized tropical convection is presented here. Both vertical/baroclinic and ...

Ying Han; Boualem Khouider

2010-09-01T23:59:59.000Z

177

Organizational Modes of Midlatitude Mesoscale Convective Systems  

Science Conference Proceedings (OSTI)

This paper discusses common modes of mesoscale convective organization. Using 2-km national composite reflectivity data, the authors investigated linear mesoscale convective systems (MCSs) that occurred in the central United States during May ...

Matthew D. Parker; Richard H. Johnson

2000-10-01T23:59:59.000Z

178

Predicting the Movement of Mesoscale Convective Complexes  

Science Conference Proceedings (OSTI)

A procedure for operationally predicting the movement of the mesobeta-scale convective elements responsible for the heavy rain in mesocale convective complexes is presented. The procedure is based on the well-known concepts that the motion of ...

S. F. Corfidi; J. H. Meritt; J. M. Fritsch

1996-03-01T23:59:59.000Z

179

Helicity and Thermal Convection with Shear  

Science Conference Proceedings (OSTI)

The relations between nonlinear energy transport and helicity of the flow are studied through simulations of thermal convection with mean shear. Parallel-plate convection with a rotating mean shear, a linear undirectional shear, a parabolic ...

Wan-Shu Wu; Douglas K. Lilly; Robert M. Kerr

1992-10-01T23:59:59.000Z

180

Preconditioning Deep Convection with Cumulus Congestus  

Science Conference Proceedings (OSTI)

Recent studies have pushed forward the idea that congestus clouds, through their moistening of the atmosphere, could promote deep convection. On the other hand, older studies have tended to relate convective initiation to the large-scale forcing. ...

Cathy Hohenegger; Bjorn Stevens

2013-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "measurement variable convection" 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 Transilient Matrix for Moist Convection  

Science Conference Proceedings (OSTI)

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? for the ...

David M. Romps; Zhiming Kuang

2011-09-01T23:59:59.000Z

182

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

183

A numerical simulation of slantwise convection: its structure and evolution  

E-Print Network (OSTI)

Weather forecasters have had difficulty forecasting mesoscale precipitation bands occurring in the regions of frontal zones. Within the last twenty years, slantwise convection (SC) through the release of conditional symmetric instability (CSI) has gained more acceptance as the cause of the rainbands under certain conditions. Bennetts and Hoskins (1979) predict that under saturated conditions, CSI would be released, forming slantwise roll circulations with sloping updrafts and downdrafts (slantwise convection), and could be a possible explanation for frontal rainbands. This study uses the Penn State/NCAR Mesoscale Model (MM5) as a diagnostic tool to simulate a slantwise convective case from the Genesis of Atlantic Lows Experiment (GALE, Dirks et al. 1988) intensive observing period 1 (IOP1, 18 January 1986 to 20 January 1986). The model results show that SC formed in an 'upscale' development as suggested by Xu (1986) with SC dominating over upright convection. The results showed that in SC's development stage, the beginning of a roll circulation with a slanted updraft and a broad downdraft with a rear inflow jet. SC in its mature stage exhibits a well developed roll circulation, a 3-dimensional structure with along-line variability, stages of re-development suggesting a quasi-steady state, and the non-conservation of negative equivalent potential vorticity (-EPV). Eventually, SC decays as it can no longer generate CSI for release. The SC compared well with other SC bands in the event and showed similar structure as observed in radar data.

Overpeck, Scott Allen

2001-01-01T23:59:59.000Z

184

Mountain-Induced Convection under Fair Weather Conditions  

Science Conference Proceedings (OSTI)

Measurements of the structure of dry convection over an isolated mountain range heated by the sun are presented. Filter techniques are used to deduce those scales of motion of significance to the circulation. A two-scale process is observed in ...

David Raymond; Marvin Wilkening

1980-12-01T23:59:59.000Z

185

First measurement of the small-scale spatial variability of the rain drop size distribution: Results from a crucial experiment and maximum entropy modeling  

E-Print Network (OSTI)

The main challenges of measuring precipitation are related to the spatio-temporal variability of the drop-size distribution, to the uncertainties that condition the modeling of that distribution, and to the instrumental errors present in the in situ estimations. This PhD dissertation proposes advances in all these questions. The relevance of the spatial variability of the drop-size distribution for remote sensing measurements and hydro-meteorology field studies is asserted by analyzing the measurement of a set of disdrometers deployed on a network of 5 squared kilometers. This study comprises the spatial variability of integral rainfall parameters, the ZR relationships, and the variations within the one moment scaling method. The modeling of the drop-size distribution is analyzed by applying the MaxEnt method and comparing it with the methods of moments and the maximum likelihood. The instrumental errors are analyzed with a compressive comparison of sampling and binning uncertainties that affect actual device...

Checa-Garcia, Ramiro

2013-01-01T23:59:59.000Z

186

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

187

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

188

Rapid Rotation, Active Nests of Convection and Global-scale Flows in Solar-like Stars  

E-Print Network (OSTI)

In the solar convection zone, rotation couples with intensely turbulent convection to build global-scale flows of differential rotation and meridional circulation. Our sun must have rotated more rapidly in its past, as is suggested by observations of many rapidly rotating young solar-type stars. Here we explore the effects of more rapid rotation on the patterns of convection in such stars and the global-scale flows which are self-consistently established. The convection in these systems is richly time dependent and in our most rapidly rotating suns a striking pattern of spatially localized convection emerges. Convection near the equator in these systems is dominated by one or two patches of locally enhanced convection, with nearly quiescent streaming flow in between at the highest rotation rates. These active nests of convection maintain a strong differential rotation despite their small size. The structure of differential rotation is similar in all of our more rapidly rotating suns, with fast equators and slower poles. We find that the total shear in differential rotation, as measured by latitudinal angular velocity contrast, Delta_Omega, increases with more rapid rotation while the relative shear, Delta_Omega/Omega, decreases. In contrast, at more rapid rotation the meridional circulations decrease in both energy and peak velocities and break into multiple cells of circulation in both radius and latitude.

Benjamin P. Brown; Matthew K. Browning; Allan Sacha Brun; Mark S. Miesch; Juri Toomre

2008-01-10T23:59:59.000Z

189

Fully Lagrangian Floats in Labrador Sea Deep Convection: Comparison of Numerical and Experimental Results  

Science Conference Proceedings (OSTI)

Measurements of deep convection from fully Lagrangian floats deployed in the Labrador Sea during February and March 1997 are compared with results from model drifters embedded in a large eddy simulation (LES) of the rapidly deepening mixed layer. ...

Ramsey R. Harcourt; Elizabeth L. Steffen; Roland W. Garwood; Eric A. D'Asaro

2002-02-01T23:59:59.000Z

190

CAPE and Convective Events in the Southwest during the North American Monsoon  

Science Conference Proceedings (OSTI)

The relationship between atmospheric stability, measured as CAPE, and deep precipitating convection has been widely studied but is not definitive. In the maritime tropics, CAPE and precipitation are usually inversely correlated. In continental ...

David K. Adams; Enio P. Souza

2009-01-01T23:59:59.000Z

191

Local Structure of the Convective Boundary Layer from a Volume-Imaging Radar  

Science Conference Proceedings (OSTI)

The local structure and evolution of the convective boundary layer (CBL) are studied through measurements obtained with a volume-imaging radar, the turbulent eddy profiler (TEP). TEP has the unique ability to image the temporal and spatial ...

Brian D. Pollard; Samir Khanna; Stephen J. Frasier; John C. Wyngaard; Dennis W. Thomson; Robert E. McIntosh

2000-07-01T23:59:59.000Z

192

On the Modification Potential of Illinois Summertime Convective Clouds, with Comparisons to Florida and FACE Observations  

Science Conference Proceedings (OSTI)

The potential for enhancing rain output over central Illinois through modification of summertime convective clouds was investigated by use of model predictions of cumulus growth, as well as direct, internal measurements of cloud physical ...

Victor Wiggert; Robert I. Sax; Ronald L. Holle

1982-09-01T23:59:59.000Z

193

Mesoscale Downdraft Influences on Vertical Vorticity in a Mature Mesoscale Convective System  

Science Conference Proceedings (OSTI)

The vorticity dynamics of a lower-tropospheric mesovortex within a mature mesoscale convective system (MCS) is investigated with observations from a special sounding network and with dual-Doppler radar measurements. The data show that the ...

Edward A. Brandes; Conrad L. Ziegler

1993-05-01T23:59:59.000Z

194

Convective Transport Theory for Surface Fluxes Tested over the Western Pacific Warm Pool  

Science Conference Proceedings (OSTI)

Turbulent flux measurements from five flights of the National Center for Atmospheric Research Electra aircraft during the Tropical Oceans and Global Atmosphere Coupled Ocean–Atmosphere Response Experiment (TOGA COARE) are used to test convective ...

Lawrence Greischar; Roland Stull

1999-07-01T23:59:59.000Z

195

Improving Simulations of Convective Systems from TRMM LBA: Easterly and Westerly Regimes  

Science Conference Proceedings (OSTI)

The 3D Goddard Cumulus Ensemble model is used to simulate two convective events observed during the Tropical Rainfall Measuring Mission Large-Scale Biosphere–Atmosphere (TRMM LBA) experiment in Brazil. These two events epitomized the type of ...

S. Lang; W-K. Tao; J. Simpson; R. Cifelli; S. Rutledge; W. Olson; J. Halverson

2007-04-01T23:59:59.000Z

196

Possibility of the Visible-Channel Calibration Using Deep Convective Clouds Overshooting the TTL  

Science Conference Proceedings (OSTI)

The authors examined the possible use of deep convective clouds (DCCs), defined as clouds that overshoot the tropical tropopause layer (TTL), for the calibration of satellite measurements at solar channels. DCCs are identified in terms of the ...

B-J. Sohn; Seung-Hee Ham; Ping Yang

2009-11-01T23:59:59.000Z

197

Signatures of Doubly Diffusive Convection and Turbulence in an Intrusive Regime  

Science Conference Proceedings (OSTI)

Doubly diffusive convection and turbulence were measured from a submarine in a region where the mean gradients do not support doubly diffusive processes but intrusions provide favorable sites. The stability of the submarine-mounted CTD system ...

Thomas R. Osborn

1988-01-01T23:59:59.000Z

198

Observational Study of the Entrainment-Mixing Process in Warm Convective Clouds  

Science Conference Proceedings (OSTI)

Thermodynamical and microphysical measurements collected in convective clouds are examined within the frame of the homogeneous/inhomogeneous mixing concept, to determine how entrainment-mixing processes affect cloud droplets, their number ...

Frédéric Burnet; Jean-Louis Brenguier

2007-06-01T23:59:59.000Z

199

Dynamics of Sheared Convective Boundary Layer Entrainment. Part I: Methodological Background and Large-Eddy Simulations  

Science Conference Proceedings (OSTI)

The reported study examines the dynamics of entrainment and its effects on the evolution of the dry atmospheric convective boundary layer (CBL) when wind shear is present. The sheared CBL can be studied by means of direct measurements in the ...

Robert J. Conzemius; Evgeni Fedorovich

2006-04-01T23:59:59.000Z

200

An Observational Study of Convection Initiation on 12 June 2002 during IHOP_2002  

Science Conference Proceedings (OSTI)

The International H2O Project (IHOP_2002) was designed to sample the three-dimensional time-varying moisture field to better understand convective processes. Numerous research and operational water vapor measuring systems and retrievals, via in ...

Tammy M. Weckwerth; Hanne V. Murphey; Cyrille Flamant; Janine Goldstein; Crystalyne R. Pettet

2008-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "measurement variable convection" 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

An Indirect Estimation of Convective Boundary Layer Structure for Use in Pollution Dispersion Models  

Science Conference Proceedings (OSTI)

Dispersion models of the convectively driven atmospheric boundary layer (ABL) often require as input meteorological parameters that are not routinely measured. These parameters usually include the surface fluxes of heat and momentum ?Cpw???and ?u?w?, the ...

James M. Wilczak; Mary Sue Phillips

1986-11-01T23:59:59.000Z

202

Mesoscale Convective Systems over Western Equatorial Africa and Their Relationship to Large-Scale Circulation  

Science Conference Proceedings (OSTI)

This study examines mesoscale convective systems (MCSs) over western equatorial Africa using data from the Tropical Rainfall Measuring Mission (TRMM) satellite. This region experiences some of the world’s most intense thunderstorms and highest ...

Brian Jackson; Sharon E. Nicholson; Douglas Klotter

2009-04-01T23:59:59.000Z

203

Retrieved Thermodynamic Structure of a Subtropical, Orographically Influenced, Quasi-Stationary Convective Line  

Science Conference Proceedings (OSTI)

Airborne Doppler radar and flight-level measurements were used to document the three-dimensional thermodynamic structure of a convective line that developed off the southeastern coast of Taiwan on 16 June 1987 during the Taiwan Area Mesoscale ...

Cheng-Ku Yu; Ben Jong-Dao Jou; David P. Jorgensen

2001-05-01T23:59:59.000Z

204

A Satellite Analysis of Deep Convection, Upper-Tropospheric Humidity, and the Greenhouse Effect  

Science Conference Proceedings (OSTI)

This paper combines satellite measurements of the upwelling 6.7-?m radiance from TOVS with cloud-property information from ISCCP and outgoing longwave radiative fluxes from ERBE to analyze the climatological interactions between deep convection, ...

Brian J. Soden; Rong Fu

1995-10-01T23:59:59.000Z

205

The Diurnal Interaction Between Convection and Peninsular-Scale Forcing Over South Florida  

Science Conference Proceedings (OSTI)

Surface wind measurements taken during the summers of 1973 and 1975 in the Florida Area Cumulus Experiments (FACE) fine-mesh networks are used to calculate surface divergence on the convective scale and mesoscale.

H. J. Cooper; M. Garstang; J. Simpson

1982-06-01T23:59:59.000Z

206

A Summary of Convective-Core Vertical Velocity Properties Using ARM UHF Wind Profilers in Oklahoma  

Science Conference Proceedings (OSTI)

This study presents a summary of the properties of deep convective updraft and downdraft cores over the central plains of the United States, accomplished using a novel and now-standard Atmospheric Radiation Measurement Program (ARM) scanning mode ...

Scott E. Giangrande; Scott Collis; Jerry Straka; Alain Protat; Christopher Williams; Steven Krueger

2013-10-01T23:59:59.000Z

207

Statistical Characteristics of Convective Storms in Belgium Derived from Volumetric Weather Radar Observations  

Science Conference Proceedings (OSTI)

High-resolution volumetric reflectivity measurements from a C-band weather radar are used to study the characteristics of convective storms in Belgium. After clutter filtering, the data are processed by the storm-tracking system Thunderstorm ...

Edouard Goudenhoofdt; Laurent Delobbe

2013-04-01T23:59:59.000Z

208

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

209

Rainfall Estimation from Polarimetric Radar Measurements: Composite Algorithms Immune to Variability in Raindrop Shape–Size Relation  

Science Conference Proceedings (OSTI)

Polarization diversity radar measurements such as reflectivity factor, differential reflectivity, and differential propagation phase are extensively used in rainfall estimation. Algorithms to estimate rainfall from polarimetric radar measurements ...

Eugenio Gorgucci; Gianfranco Scarchilli; V. Chandrasekar; V. N. Bringi

2001-11-01T23:59:59.000Z

210

This study aims to quantify the effects of topographic vari-ability (measured by coefficient variation of elevation, CV) and  

E-Print Network (OSTI)

, and topographic variability. Introduction As defined by the U.S. Geological Survey, a grid Digital Elevation Model transmission of a laser PHOTOGRAMMETRIC ENGINEERING & REMOTE SENSING June 2010 1 Sierra Nevada Research). The use of airborne lidar sensors for topographic mapping is rapidly becoming a standard practice

Guo, Qinghua

211

Sensitivity of Convective Cloud Growth to Mesoscale Lifting: A Numerical Analysis of Mesoscale Convective Triggering  

Science Conference Proceedings (OSTI)

Numerical model simulation of mesoscale lifting of the convective environment indicates that the ability of the environment to develop deep moist convection increases as mesoscale lifting increases. Mesoscale lifting produces increases in modeled ...

David A. Matthews; Bernard A. Silverman

1980-07-01T23:59:59.000Z

212

Convective Inhibition as a Predictor of Convection during AVE-SESAME II  

Science Conference Proceedings (OSTI)

The AVE-SESAME 11 data set of 19 April 1979 is examined to determine the thermodynamic conditions prior to the onset of deep convection in western Kansas. The observations indicate that the convective region was characterized locally by ...

Frank P. Colby Jr.

1984-11-01T23:59:59.000Z

213

Convective Evolution and Merger in the FACE Experimental Area: Mesoscale Convection and Boundary Layer Interactions  

Science Conference Proceedings (OSTI)

This paper investigates the interactions between the various scales of motion and, specifically, the inter-actions between convection and the surface boundary layer in the development of a mesoscale convective system within the Florida Area ...

John B. Cunning; Ronald L. Holle; Patrick T. Gannon; Andrew I. Watson

1982-07-01T23:59:59.000Z

214

Interactions between Shallow and Deep Convection under a Finite Departure from Convective Quasi Equilibrium  

Science Conference Proceedings (OSTI)

The present paper presents a simple theory for the transformation of nonprecipitating, shallow convection into precipitating, deep convective clouds. To make the pertinent point a much idealized system is considered, consisting only of shallow and ...

Jun-Ichi Yano; Robert Plant

2012-12-01T23:59:59.000Z

215

Mesoscale Convective Vortices Observed during BAMEX. Part II: Influences on Secondary Deep Convection  

Science Conference Proceedings (OSTI)

Observations from the Bow Echo and Mesoscale Convective Vortex (MCV) Experiment are used to examine the role of the five mesoscale convective vortices described in Part I on heavy precipitation during the daytime heating cycle. Persistent ...

Stanley B. Trier; Christopher A. Davis

2007-06-01T23:59:59.000Z

216

Sensitivity of Forecast Rainfall in a Texas Convective System to Soil Moisture and Convective Parameterization  

Science Conference Proceedings (OSTI)

The impact of soil moisture on the forecast of a small-scale convective system, and sensitivity of results to the convective parameterization used, are investigated through Eta Model simulations (run in an operational-like setting) of a ...

William A. Gallus Jr.; Moti Segal

2000-10-01T23:59:59.000Z

217

A Parameter Study of Interactions Between Convective Clouds, the Convective Boundary Layer, and a Forested Surface  

Science Conference Proceedings (OSTI)

A numerical model was developed which included cloud parameterizations, a convective boundary layer, solar and longwave radiation, a soil layer and a parameterized forest layer. The model simulated the growth of the convective boundary layer and ...

Alfred J. Garrett

1982-08-01T23:59:59.000Z

218

Multiscale Convective Overturning in Mesoscale Convective Systems: Reconciling Observations, Simulations, and Theory  

Science Conference Proceedings (OSTI)

An analysis of how parameterized convection interacts with hydrostatic, explicitly resolved precipitation processes to represent multiscale convective overturning in a mesoscale-resolution numerical simulation is presented. Critically important ...

John S. Kain; J. Michael Fritsch

1998-08-01T23:59:59.000Z

219

An Estimation of the Condensation Rates in Three Severe Storm Systems from Satellite Observations of the Convective Mass Flux  

Science Conference Proceedings (OSTI)

A technique was developed for estimating the condensation rates of convective storms using satellite measurements of cirrus anvil expansion rates and radiosonde measurements of environmental water vapor. Three cases of severe conviction in ...

Robert A. Mack; Donald P. Wylie

1982-07-01T23:59:59.000Z

220

Tropical Pacific impacts of convective momentum ... - Springer  

Science Conference Proceedings (OSTI)

MJO and monsoons, either directly by changing the atmospheric response to convection, or indirectly by altering the background climatology and ENSO. In fact

Note: This page contains sample records for the topic "measurement variable convection" 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

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...

222

Geothermal: Sponsored by OSTI -- Improving Convection Parameterization...  

Office of Scientific and Technical Information (OSTI)

Improving Convection Parameterization Using ARM Observations and NCAR Community Atmosphere Model Geothermal Technologies Legacy Collection HelpFAQ | Site Map | Contact Us | Admin...

223

High-Resolution Atmospheric Sensing of Multiple Atmospheric Variables Using the DataHawk Small Airborne Measurement System  

Science Conference Proceedings (OSTI)

The DataHawk small airborne measurement system provides in situ atmospheric measurement capabilities for documenting scales as small as 1 m and can access reasonably large volumes in and above the atmospheric boundary layer at low cost. The design ...

Dale A. Lawrence; Ben B. Balsley

2013-10-01T23:59:59.000Z

224

Parameterization of Convective Momentum Transport in Highly Baroclinic Conditions  

Science Conference Proceedings (OSTI)

The organization of convection by vertical shear strongly affects the transport of horizontal momentum, yet the concept of organization has received little attention in convective parameterization. Here the focus is on open-cellular convection in ...

Vanda Grubiši?; Mitchell W. Moncrieff

2000-09-01T23:59:59.000Z

225

Structure of the Atmosphere in Radiative–Convective Equilibrium  

Science Conference Proceedings (OSTI)

To investigate water vapor transport in an atmosphere in radiative–convective equilibrium, a simplified dynamical convection model (DCM) was constructed that explicitly models moist convection and longwave radiation in a gray atmosphere. In the ...

Yoshiharu Iwasa; Yutaka Abe; Hiroshi Tanaka

2002-07-01T23:59:59.000Z

226

Elevated Convection and Castellanus: Ambiguities, Significance, and Questions  

Science Conference Proceedings (OSTI)

The term elevated convection is used to describe convection where the constituent air parcels originate from a layer above the planetary boundary layer. Because elevated convection can produce severe hail, damaging surface wind, and excessive ...

Stephen F. Corfidi; Sarah J. Corfidi; David M. Schultz

2008-12-01T23:59:59.000Z

227

Deep Convection and “First Echoes” within Anvil Precipitation  

Science Conference Proceedings (OSTI)

The development of convective cells within anvil precipitation, in a region of moderate convective activity that might be called a small mesoscale convective system, is described and discussed. The presence of precipitation-sized hydrometeors in ...

Charles A. Knight; L. Jay Miller; William D. Hall

2004-07-01T23:59:59.000Z

228

Performance Variability  

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

Variability Variability of Highly Parallel Architectures William T.C. Kramer 1 and Clint Ryan 2 1 Department of Computing Sciences, University of California at Berkeley and the National Energy Research Scientific Computing Center, Lawrence Berkeley National Laboratory 2 Department of Computing Sciences, University of California at Berkeley Abstract. The design and evaluation of high performance computers has concentrated on increasing computational speed for applications. This performance is often measured on a well configured dedicated sys- tem to show the best case. In the real environment, resources are not always dedicated to a single task, and systems run tasks that may influ- ence each other, so run times vary, sometimes to an unreasonably large extent. This paper explores the amount of variation seen across four large distributed memory systems in a systematic manner. It then

229

Intraseasonal Convective Perturbations Related to the Seasonal March of the Indo-Pacific Monsoons  

Science Conference Proceedings (OSTI)

The seasonal evolution of the 20–90-day intraseasonal variability (ISV) of the convection in the Indo-Pacific region presents intriguing features related to monsoon dynamics: (i) a sharp ISV maximum in May for the southern Bay of Bengal and in ...

H. Bellenger; J. P. Duvel

2007-06-01T23:59:59.000Z

230

The Use of lce-Liquid Water Potential Temperature as a Thermodynamic Variable In Deep Atmospheric Models  

Science Conference Proceedings (OSTI)

Previous studies have shown liquid water potential temperature to be an inappropriate choice for a thermodynamic variable in a deep cumulus convection model. In this study, an alternate form of this variable called ice-liquid water potential ...

Gregory J. Tripoli; William R. Cotton

1981-05-01T23:59:59.000Z

231

Convection Initiation and Downburst Experiment (CINDE)  

Science Conference Proceedings (OSTI)

The Convection Initiation and Downburst Experiment (CINDE) was conducted in the Denver, Colorado area from 22 June to 7 August 1987 to study processes leading to the formation of deep convection and the physics of downbursts. A total of 6 Doppler ...

James W. Wilson; James A. Moore; G. Brant Foote; Brooks Martner; Taneil Uttal; James M. Wilczak; Alfred R. Rodi

1988-11-01T23:59:59.000Z

232

Nature versus Nurture in Shallow Convection  

Science Conference Proceedings (OSTI)

Tracers are used in a large-eddy simulation of shallow convection to show that stochastic entrainment (and not cloud-base properties) determines the fate of convecting parcels. The tracers are used to diagnose the correlations between a parcel’s ...

David M. Romps; Zhiming Kuang

2010-05-01T23:59:59.000Z

233

High-Resolution Atmospheric Sensing of Multiple Atmospheric Variables Using the DataHawk Small Airborne Measurement System  

Science Conference Proceedings (OSTI)

The DataHawk small airborne measurement system provides in-situ atmospheric measurement capabilities for documenting scales as small as 1 m and can access reasonably large volumes in and above the atmospheric boundary layer at low cost. The design ...

Dale A. Lawrence; Ben B. Balsley

234

Suborbital Measurements of Spectral Aerosol Optical Depth and Its Variability at Subsatellite Grid Scales in Support of CLAMS 2001  

Science Conference Proceedings (OSTI)

As part of the Chesapeake Lighthouse and Aircraft Measurements for Satellites (CLAMS) experiment, 10 July–2 August 2001, off the central East Coast of the United States, the 14-channel NASA Ames Airborne Tracking Sunphotometer (AATS-14) was ...

J. Redemann; B. Schmid; J. A. Eilers; R. Kahn; R. C. Levy; P. B. Russell; J. M. Livingston; P. V. Hobbs; W. L. Smith Jr.; B. N. Holben

2005-04-01T23:59:59.000Z

235

Reco level Smin and subsystem Smin: improved global inclusive variables for measuring the new physics mass scale in MET events at hadron colliders  

SciTech Connect

The variable {radical}s{sub min} was originally proposed in [1] as a model-independent, global and fully inclusive measure of the new physics mass scale in missing energy events at hadron colliders. In the original incarnation of {radical}s{sub min}, however, the connection to the new physics mass scale was blurred by the effects of the underlying event, most notably initial state radiation and multiple parton interactions. In this paper we advertize two improved variants of the {radical}s{sub min} variable, which overcome this problem. First we show that by evaluating the {radical}s{sub min} variable at the RECO level, in terms of the reconstructed objects in the event, the effects from the underlying event are significantly diminished and the nice correlation between the peak in the {radical}s{sub min}{sup (reco)} distribution and the new physics mass scale is restored. Secondly, the underlying event problem can be avoided altogether when the {radical}s{sub min} concept is applied to a subsystem of the event which does not involve any QCD jets. We supply an analytic formula for the resulting subsystem {radical}s{sub min}{sup (sub)} variable and show that its peak exhibits the usual correlation with the mass scale of the particles produced in the subsystem. Finally, we contrast {radical}s{sub min} to other popular inclusive variables such as H{sub T}, M{sub Tgen} and M{sub TTgen}. We illustrate our discussion with several examples from supersymmetry, and with dilepton events from top quark pair production.

Konar, Partha; /Florida U.; Kong, Kyoungchul; /SLAC; Matchev, Konstantin T.; Park, Myeonghun; /Florida U.

2011-08-11T23:59:59.000Z

236

Measurement of Cloud Perturbation Pressures Using an Instrumented Aircraft  

Science Conference Proceedings (OSTI)

Vertical accelerations during the early stages of convective cloud formation are often the result of buoyancy and the perturbation vertical pressure gradient forces. Convection modifies the local pressure field surrounding the cloud. Measurement ...

Thomas R. Parish; David Leon

2013-02-01T23:59:59.000Z

237

Healthy transportation - healthy communities: developing objective measures of built-environment using GIS and testing significance of pedestrian variables on walking to transit  

E-Print Network (OSTI)

Walking to transit stations is proposed as one of the strategies to increase the use of transit. Urban planners, transportation planners, environmentalists, and health professionals encourage and support environmental interventions that can reduce the use of cars for all kinds of trips and use alternative modes of travel such as walking, biking, and mass-transit. This study investigates the influence of the built-environment on walking to transit stations. Transit-oriented communities at quarter and half-mile distances from the Dallas Area Rapid Transit (DART) station in Dallas, Texas, were analyzed to identify the relation of various constructs of built-environment on walking to the DART stations. Twenty-one pedestrian indices were reviewed to develop a comprehensive list of 73 built-environment variables used to measure the suitability to walk. This study aims to objectively measure built-environment using spatial data. Based on this criterion the total number of variables was narrowed to 32. Walking to transit, calculated as a percentage of transit users who walk to the DART LRT stations, was used as the dependent variable. The number of stations in operation and used for analysis in this study is 20(n). Therefore, bootstrapping was used to perform the statistical analysis for this study. The final pattern of variable grouping for the quarter-mile and the half-mile analysis revealed four principal components: Vehicle-Oriented Design, Density, Diversity, and Walking-Oriented Design. Bootstrap regression revealed that density ( = -0.767) was the only principal component that significantly (p<0.05) explained walking to transit station at quarter-mile distance from the station. At half-mile distance built-environment variables did not report any significant relation to walking to transit. The present study revealed that mere increase of density should not be taken as a proxy of increase in walking. Environmental interventions that can promote walking should be identified even at locations with high density. Further studies should use advanced statistical techniques such as Hierarchical Linear Modeling or Structural Equation Modeling to test the relationship of both the principal components and the individual variables that define the principal component to clearly understand the relationship of built-environment with walking to transit station.

Maghelal, Praveen Kumar

2007-08-01T23:59:59.000Z

238

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

239

Prandtl Number Dependent Natural Convection with Internal Heat Sources  

SciTech Connect

Natural convection plays an important role in determining the thermal load from debris accumulated in the reactor vessel lower head during a severe accident. Recently, attention is being paid to the feasibility of external vessel flooding as a severe accident management strategy and to the phenomena affecting the success path for retaining the molten core material inside the vessel. The heat transfer inside the molten core material can be characterized by the strong buoyancy-induced flows resulting from internal heating due to decay of fission products. The thermo-fluid dynamic characteristics of such flow depend strongly on the thermal boundary conditions. The spatial and temporal variation of heat flux on the pool wall boundaries and the pool superheat are mainly characterized by the natural convection flow inside the molten pool. In general, the natural convection heat transfer phenomena involving the internal heat generation are represented by the modified Rayleigh number (Ra’), which quantifies the internal heat source and hence the strength of the buoyancy force. In this study, tests were conducted in a rectangular section 250 mm high, 500 mm long and 160 mm wide. Twenty-four T-type thermocouples were installed in the test section to measure temperatures. Four T-type thermocouples were used to measure the boundary temperatures. The thermocouples were placed in designated locations after calibration. A direct heating method was adopted in this test to simulate the uniform heat generation. The experiments covered a range of Ra' between 1.5x106 and 7.42x1015 and the Prandtl number (Pr) between 0.7 and 6.5. Tests were conducted with water and air as simulant. The upper and lower boundary conditions were maintained uniform. The results demonstrated feasibility of the direct heating method to simulate uniform volumetric heat generation. Particular attentions were paid to the effect of Pr on natural convection heat transfer within the rectangular pool.

Kang Hee Lee; Seung Dong Lee; Kune Y. Suh; Joy L. Rempe; Fan-Bill Cheung; Sang B. Kim

2004-06-01T23:59:59.000Z

240

Convective heat transfer inside passive solar buildings  

DOE Green Energy (OSTI)

Natural convection between spaces in a building can play a major role in energy transfer. Two situations are investigated: convection through a single doorway into a remote room, and a convective loop in a two-story house with a south sunspace where a north stairway serves as the return path. A doorway-sizing equation is given for the single-door case. Detailed data are given from the monitoring of airflow in one two-story house and summary data are given for five others. Observations on the nature of the airflow and design guidelines are presented.

Jones, R.W.; Balcomb, J.D.; Yamaguchi, K.

1983-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "measurement variable convection" 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

Parameterization of Joint Frequency Distributions of Potential Temperature and Water Vapor Mixing Ratio in the Daytime Convective Boundary Layer  

Science Conference Proceedings (OSTI)

Joint frequency distributions (JFDs) of potential temperature (?) versus water vapor mixing ratio (r) within the convective boundary layer were measured during a new field experiment named Boundary Layer Experiment 1996 (BLX96). These JFDs were ...

Larry K. Berg; Roland B. Stull

2004-04-01T23:59:59.000Z

242

Convective and Rainfall Properties of Tropical Cyclone Inner Cores and Rainbands from 11 Years of TRMM Data  

Science Conference Proceedings (OSTI)

Convective and rainfall properties of tropical cyclones (TCs) are statistically quantified by using Tropical Rainfall Measuring Mission (TRMM) data from December 1997 to December 2008. A semimanual method is used to divide the TC raining area into ...

Haiyan Jiang; Ellen M. Ramirez; Daniel J. Cecil

2013-02-01T23:59:59.000Z

243

Similarity of Deep Continental Cumulus Convection as Revealed by a Three-Dimensional Cloud-Resolving Model  

Science Conference Proceedings (OSTI)

A three-dimensional cloud-resolving simulation of midlatitude continental convection during the Atmospheric Radiation Measurement (ARM) program summer 1997 intensive observation period (IOP) is used to study the similarity of several second and ...

Marat F. Khairoutdinov; David A. Randall

2002-09-01T23:59:59.000Z

244

Observations of Deep Convection in the Gulf of Lions, Northern Mediterranean, during the Winter of 1991/92  

Science Conference Proceedings (OSTI)

During December 1991 to April 1992 measurements with moored acoustic Doppler current profiler (ADCP) stations and shipboard surveys were carried out in the convection regime of the Gulf of Lions, northwestern Mediterranean. First significant ...

Friedrich Schott; Martin Visbeck; Uwe Send; Jürgen Fischer; Lothar Stramma; Yves Desaubies

1996-04-01T23:59:59.000Z

245

Statistics of Drop Size Distribution Parameters and Rain Rates for Stratiform and Convective Precipitation during the North Australian Wet Season  

Science Conference Proceedings (OSTI)

C-band polarimetric radar measurements spanning two wet seasons are used to study the effects of the large-scale environment on the statistical properties of stratiform and convective rainfall around Darwin, Australia. The rainfall physical ...

Guillaume Penide; Vickal V. Kumar; Alain Protat; Peter T. May

2013-09-01T23:59:59.000Z

246

Intraseasonal Forcing of Convection and Lightning Activity in the Southern Amazon as a Function of Cross-Equatorial Flow  

Science Conference Proceedings (OSTI)

This study focuses on modulation of lightning and convective vertical structure in the southern Amazon as a function of the South American monsoon V index (VI). Four wet seasons (December–March 1998–2001) of Tropical Rainfall Measuring Mission (...

Walter A. Petersen; Rong Fu; Mingxuan Chen; Richard Blakeslee

2006-07-01T23:59:59.000Z

247

A General Framework for Convective Trigger Functions  

Science Conference Proceedings (OSTI)

A general framework for the trigger function used in convective parameterization routines in mesoscale models is proposed. The framework is based on the diagnosis of the accessibility of potential buoyant energy. Specifically, the trigger ...

Robert F. Rogers; J. M. Fritsch

1996-11-01T23:59:59.000Z

248

Observations and Modeling of Banded Orographic Convection  

Science Conference Proceedings (OSTI)

Radar images and numerical simulations of three shallow convective precipitation events over the Coastal Range in western Oregon are presented. In one of these events, unusually well-defined quasi-stationary banded formations produced large ...

Daniel J. Kirshbaum; Dale R. Durran

2005-05-01T23:59:59.000Z

249

Convective Systems of the North Australian Monsoon  

Science Conference Proceedings (OSTI)

The climatology of convection over northern Australia and the surrounding oceans, based on six wet seasons (September–April), is derived from the Japanese Meteorological Agency Geostationary Meteorological Satellite-5 (GMS-5) IR1 channel for the ...

Mick Pope; Christian Jakob; Michael J. Reeder

2008-10-01T23:59:59.000Z

250

Tracer dispersion in the turbulent convective layer  

Science Conference Proceedings (OSTI)

Experimental results for passive tracer dispersion in the turbulent surface layer under convective conditions are presented. In this case, the dispersion of tracer particles is determined by the interplay of two mechanisms: buoyancy and advection. ...

Alex Skvortsov; Milan Jamriska; Timothy C. DuBois

251

Convective Squalls over the Eastern Equatorial Atlantic  

Science Conference Proceedings (OSTI)

The Congo Basin and the adjacent equatorial eastern Atlantic are among the most active regions of the world in terms of intense deep moist convection, leading to frequent lightning and severe squalls. Studying the dynamics and climatology of this ...

Florian Berkes; Peter Knippertz; Douglas J. Parker; Gus Jeans; Valérie Quiniou-Ramus

2012-06-01T23:59:59.000Z

252

A Composite Model of Mesoscale Convective Complexes  

Science Conference Proceedings (OSTI)

A composite analysis technique is used to investigate the evolution of mesoscale features of mesoscale convective complexes (MCCs). The early stage of the MCC lifecycle is characterized by convergence, vertical motion and heating being centered ...

William R. Cotton; Ming-Sen Lin; Ray L. McAnelly; Craig J. Tremback

1989-04-01T23:59:59.000Z

253

Climatic Regimes of Tropical Convection and Rainfall  

Science Conference Proceedings (OSTI)

Annual distribution and phase propagation of tropical convection are delineated using harmonic and amplitude-phase characteristics analysis of climatological pentad mean outgoing longwave radiation and monthly frequencies of highly reflective ...

Bin Wang

1994-07-01T23:59:59.000Z

254

Radiation Impacts on Conditionally Unstable Moist Convection  

Science Conference Proceedings (OSTI)

The present work analyzes the impacts of radiative cooling in three-dimensional high-resolution direct numerical simulations of moist Rayleigh–Bénard convection. An atmospheric slab is destabilized by imposing a warm, moist lower boundary and a ...

Olivier Pauluis; Jörg Schumacher

2013-04-01T23:59:59.000Z

255

Resolving Convection in a Global Hypohydrostatic Model  

Science Conference Proceedings (OSTI)

Convection cannot be explicitly resolved in general circulation models given their typical grid size of 50 km or larger. However, by multiplying the vertical acceleration in the equation of motion by a constant larger than unity, the horizontal ...

S. T. Garner; D. M. W. Frierson; I. M. Held; O. Pauluis; G. K. Vallis

2007-06-01T23:59:59.000Z

256

Convective Control of ENSO Simulated in MIROC  

Science Conference Proceedings (OSTI)

The high sensitivity of the El Niño–Southern Oscillation (ENSO) to cumulus convection is examined by means of a series of climate simulations using an updated version of the Model for Interdisciplinary Research on Climate (MIROC), called MIROC5. ...

Masahiro Watanabe; Minoru Chikira; Yukiko Imada; Masahide Kimoto

2011-01-01T23:59:59.000Z

257

Estimation of Convective Rainfall from Lightning Observations  

Science Conference Proceedings (OSTI)

The objective of this study is to develop a technique to use lightning observations for estimating convective rainfall. A framework for rainfall estimation is developed in which key elements are 1) the rainfall–lightning ratio, that is, the ...

Alberto Tapia; James A. Smith; Michael Dixon

1998-11-01T23:59:59.000Z

258

Mesoscale Convective Complexes over Southern Africa  

Science Conference Proceedings (OSTI)

The maximum spatial correlation technique (MASCOTTE) is an objective and automated method developed to simultaneously determine both the structural properties and evolution (tracking) of cloud shields of convective systems. Originally designed to ...

R. C. Blamey; C. J. C. Reason

2012-01-01T23:59:59.000Z

259

Soil Moisture Impacts on Convective Margins  

Science Conference Proceedings (OSTI)

An idealized prototype for the location of the margins of tropical land region convection zones is extended to incorporate the effects of soil moisture and associated evaporation. The effect of evaporation, integrated over the inflow trajectory ...

Benjamin R. Lintner; J. David Neelin

2009-08-01T23:59:59.000Z

260

Moist Convection at a Surface Cold Front  

Science Conference Proceedings (OSTI)

The motion of a surface cold front in an environment that is unstable to moist convection is studied with the aid ofboth hydrostatic and nonhydrostatic two-dimensional models. Simulations with the hydrostatic model essentially extend the work ...

N. Andrew Crook

1987-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "measurement variable convection" 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

Rotating Convection Driven by Differential Bottom Heating  

Science Conference Proceedings (OSTI)

Convection experiments were carried out in a rectangular tank as a model of oceanic meridional overturning circulation. The objective was finding a relation between the meridional heat flux and thermal forcing. To make the meridional heat flux ...

Young-Gyu Park; J. A. Whitehead

1999-06-01T23:59:59.000Z

262

Urban Aerosol Impacts on Downwind Convective Storms  

Science Conference Proceedings (OSTI)

The impacts of urban-enhanced aerosol concentrations on convective storm development and precipitation over and downwind of St. Louis, Missouri, are investigated. This is achieved through the use of a cloud-resolving mesoscale model, in which ...

Susan C. van den Heever; William R. Cotton

2007-06-01T23:59:59.000Z

263

Interannual variability of monsoon precipitation and local subcloud equivalent potential temperature  

Science Conference Proceedings (OSTI)

The interannual variability of monsoon precipitation is described in the context of a convective quasi-equilibrium framework. Using two reanalysis products and two global precipitation datasets, we examine linear relationships between seasonal ...

John V. Hurley; William R. Boos

264

Linear variable differential transformer (LVDT)-based elongation measurements in Advanced Test Reactor high temperature irradiation testing  

Science Conference Proceedings (OSTI)

New materials are being considered for fuel, cladding, and structures in next generation and existing nuclear reactors. These materials can undergo significant dimensional and physical changes during high temperature irradiations. Currently, such changes are determined by repeatedly irradiating a specimen for a specified period of time in the Advanced Test Reactor (ATR) and then removing it from the reactor for evaluation. The labor and time to remove, examine, and return irradiated samples for each measurement makes this approach very expensive. In addition, such techniques provide limited data and may disturb the phenomena of interest. To resolve these issues, an instrumented creep testing capability is being developed for specimens irradiated in pressurized water reactor (PWR) coolant conditions in the ATR at the Idaho National Laboratory (INL). This paper reports the status of INL efforts to develop this testing capability. In addition to providing an overview of in-pile creep test capabilities available at other test reactors, this paper focuses on efforts to design and evaluate a prototype test rig in an autoclave at INL's High Temperature Test Laboratory (HTTL).

D. L. Knudson; J. L. Rempe

2012-02-01T23:59:59.000Z

265

Linear variable differential transformer (LVDT)-based elongation measurements in Advanced Test Reactor high temperature irradiation testing  

Science Conference Proceedings (OSTI)

New materials are being considered for fuel, cladding and structures in next generation and existing nuclear reactors. These materials can undergo significant dimensional and physical changes during high temperature irradiations. Currently, such changes are determined by repeatedly irradiating a specimen for a specified period of time in the Advanced Test Reactor (ATR) and then removing it from the reactor for evaluation. The labor and time to remove, examine and return irradiated samples for each measurement make this approach very expensive. In addition, such techniques provide limited data and may disturb the phenomena of interest. To resolve these issues, an instrumented creep testing capability is being developed for specimens irradiated under pressurized water reactor coolant conditions in the ATR at the Idaho National Laboratory (INL). This paper reports the status of INL efforts to develop this testing capability. In addition to providing an overview of in-pile creep test capabilities available at other test reactors, this paper focuses on efforts to design and evaluate a prototype test rig in an autoclave at INL’s High Temperature Test Laboratory.

D. L. Knudson; J. L. Rempe

2012-02-01T23:59:59.000Z

266

Nested-Model Simulation of Moist Convection: The Impact of Coarse-Grid Parameterized Convection on Fine-Grid Resolved Convection  

Science Conference Proceedings (OSTI)

Future-generation, operational, weather prediction systems will likely include storm-scale, limited-area models that will explicitly resolve convective precipitation. However, the high-resolution convection-resolving grids will need to be ...

Thomas T. Warner; Hsiao-Ming Hsu

2000-07-01T23:59:59.000Z

267

Small-Scale Variability in Warm Continental Cumulus Clouds  

Science Conference Proceedings (OSTI)

We have analyzed small-scale fluctuations in microphysical, dynamical and thermodynamical parameters measured in two warm cumulus clouds during the Cooperative Convective Precipitation Experiment (CCOPE) project (1981) in light of predictions of ...

P. H. Austin; M. B. Baker; A. M. Blyth; J. B. Jensen

1985-06-01T23:59:59.000Z

268

ARM - Midlatitude Continental Convective Clouds (jensen-sonde)  

DOE Data Explorer (OSTI)

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.

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

269

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.

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

2012-01-19T23:59:59.000Z

270

Transient natural convection in heated inclined tubes  

SciTech Connect

To simulate natural convection flow patterns in directionally drilled wellbores, experiments and analyses were conducted for a circular tube with length-to-diameter (L/D) ratio of 36 at angles of 0{degree}, 20{degree}, and 35{degree} from the vertical. The tube was heated at the bottom and cooled at the top, and the insulation was adjusted so that approximately one- to two-thirds of the power dissipated was transferred through the tube wall to the surroundings. An aqueous solution of polyvinyl alcohol was employed as the working fluid in order to obtain low Rayleigh numbers corresponding to conditions in geothermal wellbores. Results were primarily qualitative but were useful in providing insight into the phenomena occurring. Steady-state temperature distributions were measured for the three orientations and for several heating rates to demonstrate the effects of tube angle and Rayleigh number. transient measurements of the temperature distribution were obtained during cooling from a higher temperature without a heat source to calibrate the heat losses. With the electrical heat source, temporal data were taken during heating to examine the approach to steady state. Quasi-steady flow conditions were approached rapidly, but the overall time constant of the apparatus was of the order of one-third of a day. Predictions with the three-dimensional TEMPEST code were first tested by comparison with simple conduction analyses. Comparison with actual data showed good agreement of the predicted temperature levels for the maximum inclination, 35{degree}, and slightly poorer agreement for the other limit, a vertical tube. Trends of temperature level and Nusselt number with heating rate or Rayleigh number were reasonable, but the predicted variation of the end Nusselt number versus inclination was in the opposite direction from the experiment. 75 refs., 20 figs., 8 tabs.

McEligot, D.M. (Westinghouse Electric Corp., Middletown, RI (USA). Oceanic Div.); Denbow, D.A. (Software AG of North America, Inc., Lakewood, CO (USA)); Murphy, H.D. (Los Alamos National Lab., NM (USA))

1990-05-01T23:59:59.000Z

271

Solar Irradiance Variability  

E-Print Network (OSTI)

The Sun has long been considered a constant star, to the extent that its total irradiance was termed the solar constant. It required radiometers in space to detect the small variations in solar irradiance on timescales of the solar rotation and the solar cycle. A part of the difficulty is that there are no other constant natural daytime sources to which the Sun's brightness can be compared. The discovery of solar irradiance variability rekindled a long-running discussion on how strongly the Sun affects our climate. A non-negligible influence is suggested by correlation studies between solar variability and climate indicators. The mechanism for solar irradiance variations that fits the observations best is that magnetic features at the solar surface, i.e. sunspots, faculae and the magnetic network, are responsible for almost all variations (although on short timescales convection and p-mode oscillations also contribute). In spite of significant progress important questions are still open. Thus there is a debat...

Solanki, Sami K

2012-01-01T23:59:59.000Z

272

Final Report on Evaluating the Representation and Impact of Convective Processes in the NCAR Community Climate System Model  

SciTech Connect

Convection and clouds affect atmospheric temperature, moisture and wind fields through the heat of condensation and evaporation and through redistributions of heat, moisture and momentum. Individual clouds have a spatial scale of less than 10 km, much smaller than the grid size of several hundred kilometers used in climate models. Therefore the effects of clouds must be approximated in terms of variables that the model can resolve. Deriving such formulations for convection and clouds has been a major challenge for the climate modeling community due to the lack of observations of cloud and microphysical properties. The objective of our DOE CCPP project is to evaluate and improve the representation of convection schemes developed by PIs in the NCAR (National Center for Atmospheric Research) Community Climate System Model (CCSM) and study its impact on global climate simulations. • The project resulted in nine peer-reviewed publications and numerous scientific presentations that directly address the CCPP’s scientific objective of improving climate models. • We developed a package of improved convection parameterization that includes improved closure, trigger condition for convection, and comprehensive treatment of convective momentum transport. • We implemented the new convection parameterization package into several versions of the NCAR models (both coupled and uncoupled). This has led to 1) Improved simulation of seasonal migration of ITCZ; 2) Improved shortwave cloud radiative forcing response to El Niño in CAM3; 3) Improved MJO simulation in both uncoupled and coupled model; and 4) Improved simulation of ENSO in coupled model. • Using the dynamic core of CCM3, we isolated the dynamic effects of convective momentum transport. • We implemented mosaic treatment of subgrid-scale cloud-radiation interaction in CCM3.

X. Wu, G. J. Zhang

2008-04-23T23:59:59.000Z

273

ARM - Midlatitude Continental Convective Clouds - Ultra High Sensitivity Aerosol Spectrometer(tomlinson-uhsas)  

DOE Data Explorer (OSTI)

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.

Jason Tomlinson; Mike Jensen

274

ARM - Midlatitude Continental Convective Clouds Microwave Radiometer Profiler (jensen-mwr)  

DOE Data Explorer (OSTI)

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.

Mike Jensen

275

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.

Jason Tomlinson; Mike Jensen

2012-02-28T23:59:59.000Z

276

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.

Mike Jensen

2012-02-01T23:59:59.000Z

277

Hierarchy of Conservation Laws of Diffusion–Convection Equations  

E-Print Network (OSTI)

We introduce notions of equivalence of conservation laws with respect to Lie symmetry groups for fixed systems of differential equations and with respect to equivalence groups or sets of admissible transformations for classes of such systems. We also revise the notion of linear dependence of conservation laws and define the notion of local dependence of potentials. To construct conservation laws, we develop and apply the most direct method which is effective to use in the case of two independent variables. Admitting possibility of dependence of conserved vectors on a number of potentials, we generalize the iteration procedure proposed by Bluman and Doran-Wu for finding nonlocal (potential) conservation laws. As an example, we completely classify potential conservation laws (including arbitrary order local ones) of diffusion–convection equations with respect to the equivalence group and construct an exhaustive list of locally inequivalent potential systems corresponding to these equations. 1

Roman O. Popovych; Nataliya M. Ivanova

2005-01-01T23:59:59.000Z

278

Modeling Study of a Tropical Squall-Type Convective Line  

Science Conference Proceedings (OSTI)

A multidimensional and time-dependent cloud scale model is used to investigate the dynamic and micro-physical processes associated with convective and stratiform regions within a tropical squall-type convective line. The evolution of the total ...

Wei-Kuo Tao; Joanne Simpson

1989-01-01T23:59:59.000Z

279

Synoptic Environments Associated with the Training of Convective Cells  

Science Conference Proceedings (OSTI)

Many studies have been done on synoptically forced systems and heavy rainfall, but little research has gone into the forecasting of training convective storms specifically in a synoptically forced environment. Training convective storms are ...

Ryan P. Aylward; Jamie L. Dyer

2010-04-01T23:59:59.000Z

280

Mesoscale Convective Complexes over the United States during 1982  

Science Conference Proceedings (OSTI)

An important class of convective weather system, the mesoscale convective complex (MCC), presents many challenges and problems to both the research and operational communities. In addition, thew very large and long-lived thunderstorm systems have ...

D. M. Rodgers; K. W. Howard; E. C. Johnston

1983-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "measurement variable convection" 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 Tropical Convective Systems. Part I: A Cumulus Parameterization  

Science Conference Proceedings (OSTI)

A new cumulus parametefization is developed for ffse in mesoscale model simulations of precipitating convective systems. It is designed to estimate convective properties using a cloud model that interacts with the mesoscale model in a physically ...

William M. Frank; Charles Cohen

1987-12-01T23:59:59.000Z

282

Assessing the Vertical Distribution of Convective Available Potential Energy  

Science Conference Proceedings (OSTI)

Comparisons of convective available potential energy (CAPE) with standard instability indices for evaluating the convective potential of the atmosphere such as the lifted index (LI) reveal only moderate correlations. This is because the LI is a ...

David O. Blanchard

1998-09-01T23:59:59.000Z

283

Hydrography of the Labrador Sea during Active Convection  

Science Conference Proceedings (OSTI)

The hydrographic structure of the Labrador Sea during wintertime convection is described. The cruise, part of the Deep Convection Experiment, took place in February–March 1997 amidst an extended period of strong forcing in an otherwise moderate ...

Robert S. Pickart; Daniel J. Torres; R. Allyn Clarke

2002-02-01T23:59:59.000Z

284

Convective Momentum Transport over the Tropical Pacific: Budget Estimates  

Science Conference Proceedings (OSTI)

ECMWF and NCEP–NCAR reanalyses are used to calculate convective momentum transport (CMT) as a momentum budget residual over several tropical oceanic convective regions, including the TOGA COARE Intensive Flux Array (IFA). Sources of uncertainty ...

Matthew T. Carr; Christopher S. Bretherton

2001-07-01T23:59:59.000Z

285

Thermodynamic and Circulation Characteristics, of Winter Monsoon Tropical Mesoscale Convection  

Science Conference Proceedings (OSTI)

During the December 1978 field phase of the International Winter Monsoon Experiment (Winter MONEX), a regular diurnal cycle of deep convective activity occurred over the South China Sea immediately to the north of Borneo. The convection was ...

Richad H. Johnson; Donald C. Kriete

1982-12-01T23:59:59.000Z

286

Mesoscale Convective Complexes over the United States during 1983  

Science Conference Proceedings (OSTI)

Enhanced infrared satellite imagery is used to document the occurrence of mesoscale convective complexes over the United States during 1983. Thirty large convective systems are identified that display satellite-observable characteristics which ...

D. M. Rodgers; M. J. Magnano; J. H. Arns

1985-05-01T23:59:59.000Z

287

Multiscale Convective Organization and the YOTC Virtual Global Field Campaign  

Science Conference Proceedings (OSTI)

The Year of Tropical Convection (YOTC) project recognizes that major improvements are needed in how the tropics are represented in climate models. Tropical convection is organized into multiscale precipitation systems with an underlying chaotic order. ...

Mitchell W. Moncrieff; Duane E. Waliser; Martin J. Miller; Melvyn A. Shapiro; Ghassem R. Asrar; James Caughey

2012-08-01T23:59:59.000Z

288

Convection in TOGA COARE: Horizontal Scale, Morphology, and Rainfall Production  

Science Conference Proceedings (OSTI)

The occurrence frequency and rainfall production of mesoscale convective systems (MCSs) relative to smaller groups of convective clouds over the tropical oceans is not well known. Eighty days of shipboard radar data collected during the recent ...

Thomas M. Rickenbach; Steven A. Rutledge

1998-09-01T23:59:59.000Z

289

Effects of Convection Cell Geometry on Simulated Tornadoes  

Science Conference Proceedings (OSTI)

Experimental data and theory suggest that certain convection cell scale factors must be specified for correct interpretation of tornado simulations. The most important nondimensional number appears to be the ratio of convection cell depth (...

Eugene M. Wilkins; Chris J. Diamond

1987-01-01T23:59:59.000Z

290

Structures and Dynamics of Quasi-2D Mesoscale Convective Systems  

Science Conference Proceedings (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

291

Baroclinic Transition of a Long-Lived Mesoscale Convective Vortex  

Science Conference Proceedings (OSTI)

The period 5–15 June 2003, during the field phase of the Bow Echo and Mesoscale Convective Vortex (MCV) Experiment (BAMEX), was noteworthy for the wide variety of mesoscale convective systems (MCSs) that occurred. Of particular interest was a ...

Thomas J. Galarneau Jr.; Lance F. Bosart; Christopher A. Davis; Ron McTaggart-Cowan

2009-02-01T23:59:59.000Z

292

A Theory for Long-Lived Mesoscale Convective Systems  

Science Conference Proceedings (OSTI)

It is proposed that certain long-lived mesoscale convective systems maintain themselves through an interaction between quasi-balanced vertical motions and the diabatic effects of moist convection. Latent heat release, evaporation and melting of ...

D. J. Raymond; H. Jiang

1990-12-01T23:59:59.000Z

293

Linear Stratospheric Gravity Waves above Convective Thermal Forcing  

Science Conference Proceedings (OSTI)

The spectra of linear gravity waves generated by a time-varying tropospheric thermal forcing representing organized convection are compared to the spectra of stratospheric gravity waves generated by organized convection in a fully nonlinear two-...

Rajul E. Pandya; M. Joan Alexander

1999-07-01T23:59:59.000Z

294

Convective Contribution to the Genesis of Hurricane Ophelia (2005)  

Science Conference Proceedings (OSTI)

The convection occurring in the tropical depression that became Hurricane Ophelia (2005) was investigated just prior to tropical storm formation. Doppler radar showed a deep, wide, intense convective cell of a type that has been previously ...

Robert A. Houze Jr.; Wen-Chau Lee; Michael M. Bell

2009-09-01T23:59:59.000Z

295

Balanced Dynamics of Mesoscale Vortices Produced in Simulated Convective Systems  

Science Conference Proceedings (OSTI)

Long-lived, mesoscale convective systems are known to occasionally produce mesoscale convective vortices (MCVs) in the lower to middle troposphere with horizontal scales averaging 100–200 km. The formation of MCVs is investigated using fully ...

Christopher A. Davis; Morris L. Weisman

1994-07-01T23:59:59.000Z

296

Regulation of Moist Convection over the West Pacific Warm Pool  

Science Conference Proceedings (OSTI)

The mechanisms that regulate moist convection over the warm tropical oceans are not well understood. One school of thought holds that convection is caused by the convergence of moisture, which in turn is produced by an independent dynamical ...

David J. Raymond

1995-11-01T23:59:59.000Z

297

Behavior of Turbulence Statistics in the Convective Boundary Layer  

Science Conference Proceedings (OSTI)

Velocity variances in the convective boundary layer are examined using data derived in PBL experiments over land (Minnesota) and ocean (the Coral Sea) supported by data from the Kansas study of the surface boundary layer. In the freely convective ...

B. B. Hicks

1985-06-01T23:59:59.000Z

298

Scalable adaptive mantle convection simulation on petascale supercomputers  

Science Conference Proceedings (OSTI)

Mantle convection is the principal control on the thermal and geological evolution of the Earth. Mantle convection modeling involves solution of the mass, momentum, and energy equations for a viscous, creeping, incompressible non-Newtonian fluid at high ...

Carsten Burstedde; Omar Ghattas; Michael Gurnis; Georg Stadler; Eh Tan; Tiankai Tu; Lucas C. Wilcox; Shijie Zhong

2008-11-01T23:59:59.000Z

299

Convectively Driven Turbulent Mixing in the Upper Ocean  

Science Conference Proceedings (OSTI)

Two experiments were performed to study the characteristics of turbulence in convective mixed layers in the upper Ocean. In the first, a diurnal convective mixed layer developed in the Bahamas under the influence of the cycle of daytime solar ...

T. J. Shay; M. C. Gregg

1986-11-01T23:59:59.000Z

300

Implicit Versus Explicit Convective Heating in Numerical Weather Prediction Models  

Science Conference Proceedings (OSTI)

The ability of several explicit formulations of convective heating to predict the precipitation associated with a mesoscale convective complex was compared to that of a cumulus parameterization on a ½ deg latitude-longitude mesh. In the explicit ...

John Molinari; Michael Dudek

1986-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "measurement variable convection" 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

A Model to Determine Open or Closed Cellular Convection  

Science Conference Proceedings (OSTI)

A simple mechanism is proposed to help explain the observed presence in the atmosphere of open or closed cellular convection. If convection is produced by cooling concentrated near the top of the cloud layer, as in radiative cooling of stratus ...

H. Mark Helfand; Eugenia Kalnay

1983-03-01T23:59:59.000Z

302

Cloud-to-Ground Lightning Activity in Mesoscale Convective Complexes  

Science Conference Proceedings (OSTI)

A study of cloud-to-ground lightning activity attending an important subclass of mesoscale convective weather systems called the mesoscale convective complex shows that groun discharge flash rates in excess of 1000 h?1 can be sustained on average ...

S. J. Goodman; D. R. MacGorman

1986-12-01T23:59:59.000Z

303

Parameterized Updraft Mass Flux as a Predictor of Convective Intensity  

Science Conference Proceedings (OSTI)

Parameterized updraft mass flux, available as a unique predictive field from the Kain–Fritsch (KF) convective parameterization, is presented as a potentially valuable predictor of convective intensity. The KF scheme is described in some detail, ...

John S. Kain; Michael E. Baldwin; Steven J. Weiss

2003-02-01T23:59:59.000Z

304

Cycles and Propagation of Deep Convection over Equatorial Africa  

Science Conference Proceedings (OSTI)

Long-term statistics of organized convection are vital to improved understanding of the hydrologic cycle at various scales. Satellite observations are used to understand the timing, duration, and frequency of deep convection in equatorial Africa, ...

Arlene G. Laing; Richard E. Carbone; Vincenzo Levizzani

2011-09-01T23:59:59.000Z

305

Aircraft Investigation of Mesoscale Cellular Convection During AMTEX 75  

Science Conference Proceedings (OSTI)

The 1 s data set collected by the NCAR Electra research aircraft in the presence of closed mesoscale cellular convection (MCC) has been examined for the purpose of determining the convective wind field and horizontal profiles of temperature and ...

Jeffry Rothermel; Ernest M. Agee

1980-05-01T23:59:59.000Z

306

Factors Governing the Total Rainfall Yield from Continental Convective Clouds  

Science Conference Proceedings (OSTI)

Several important factors that govern the total rainfall from continental convective clouds were investigated by tracking thousands of convective cells in Israel and South Africa. The rainfall volume yield (Rvol) of the individual cells that ...

Daniel Rosenfeld; Abraham Gagin

1989-10-01T23:59:59.000Z

307

Nonlinear Effects on Convectively Forced Two-Dimensional Mesoscale Flows  

Science Conference Proceedings (OSTI)

One of the important problems in mesoscale atmospheric dynamics is how the atmosphere responds to convective heating or cooling. Here, the authors examine nonlinear effects on convectively forced mesoscale flows in the context of the nonlinear ...

Ji-Young Han; Jong-Jin Baik

2012-11-01T23:59:59.000Z

308

Physics of Greenhouse Effect and Convection in Warm Oceans  

Science Conference Proceedings (OSTI)

Sea surface temperature (SST) in roughly 50% of the tropical Pacific Ocean is warm enough (SST > 300 K) to permit deep convection. This paper examines the effects of deep convection on the climatological mean vertical distributions of water vapor ...

A. K. Inamdar; V. Ramanathan

1994-05-01T23:59:59.000Z

309

On the Features of Radiative and Convective Regimes Under the Cumulus Cloudiness  

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

On the Features of Radiative and Convective Regimes On the Features of Radiative and Convective Regimes Under the Cumulus Cloudiness B. M. Koprov, V. M. Koprov, G. S. Golitsyn A.M. Oboukhov Institute of Atmospheric Physics Moscow, Russia E. N. Kadygrov, A. V. Koldaev Central Aerological Observatory Dolgoprudny, Russia Introduction The study of instant temperature field transformation, convective and radiative regime perturbation within the layer of 0 to 650 m was fulfilled as caused by cloud modulation of solar radiation flux. It was made within the scope of Zvenigorod Atmospheric Radiation Measurement (ARM) experiments in 2001 and 2002. Instrumentation The equipment used: 1. Microwave temperature profiler designed in Central Aerological Observatory (CAO) and manufactured by Russian company ATTEX (Kadygrov and Pick 1998).

310

Comparison between Low-Flash and Non-Lightning-Producing Convective Areas within a Mature Mesoscale Convective System  

Science Conference Proceedings (OSTI)

Two small multicellular convective areas within a larger mesoscale convective system that occurred on 20 June 2004 were examined to assess vertical motion, radar reflectivity, and dual-polarimetric signatures between flash and non-flash-producing ...

Jennifer L. Palucki; Michael I. Biggerstaff; Donald R. MacGorman; Terry Schuur

2011-08-01T23:59:59.000Z

311

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

Science Conference Proceedings (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

312

Heat Flux Partitioning in Open-Ocean Convection  

Science Conference Proceedings (OSTI)

Cold air blowing out over a warm ocean leads to convection over an isolated region of the ocean basin. This phenomenon, known as open-ocean convection, is often simulated by convective forcing from a circular disk much smaller than the dimension ...

David Brickman

1995-11-01T23:59:59.000Z

313

Simulations of stellar convection with CO5BOLD  

Science Conference Proceedings (OSTI)

High-resolution images of the solar surface show a granulation pattern of hot rising and cooler downward-sinking material - the top of the deep-reaching solar convection zone. Convection plays a role for the thermal structure of the solar interior and ... Keywords: Numerical simulations, Radiation (magneto)hydrodynamics, Stellar surface convection

B. Freytag; M. Steffen; H. -G. Ludwig; S. Wedemeyer-Böhm; W. Schaffenberger; O. Steiner

2012-02-01T23:59:59.000Z

314

The Influence of Upper-Tropospheric Potential Vorticity on Convective Morphology  

Science Conference Proceedings (OSTI)

Extensive research has illuminated the roles that buoyancy and vertical wind shear have in determining convective mode. The goal of this study is to examine synoptic forcing, as measured by the form of the waves on the dynamic tropopause and the ...

Melissa R. Schumann; Paul J. Roebber

2010-02-01T23:59:59.000Z

315

Coupling of Convective Momentum Transport with Convective Heating in Global Climate Simulations  

Science Conference Proceedings (OSTI)

The effects of convective momentum transport (CMT) on global climate simulations are examined in this study. Comparison between two sets of 20-yr (1979–98) integration using the NCAR Community Climate Model version 3 (CCM3) illustrates that the ...

Xiaoqing Wu; Liping Deng; Xiaoliang Song; Guang Jun Zhang

2007-04-01T23:59:59.000Z

316

Response of Tropical Deep Convection to Localized Heating Perturbations: Implications for Aerosol-Induced Convective Invigoration  

Science Conference Proceedings (OSTI)

A cloud-system-resolving model is used to investigate the effects of localized heating/cooling perturbations on tropical deep convection, in the context of the aerosol “invigoration effect.” This effect supposes that a reduction of droplet ...

Hugh Morrison; Wojciech W. Grabowski

2013-11-01T23:59:59.000Z

317

Unsteady, Turbulent Convection into a Rotating, Linearly Stratified Fluid: Modeling Deep Ocean Convection  

Science Conference Proceedings (OSTI)

A laboratory experiment has been constructed to Model the deep convective processes in a stratified ocean driven by the energetic cooling at the ocean surface. For convenience in the laboratory the authors have examined the analogous but inverted ...

M. J. Coates; G. N. Ivey; J. R. Taylor

1995-12-01T23:59:59.000Z

318

Numerical Prediction of Convectively Driven Mesoscale Pressure Systems. Part I: Convective Parameterization  

Science Conference Proceedings (OSTI)

A parameterization formulation for incorporating the effects of midlatitude deep convection into mesoscale-numerical models is presented. The formulation is based on the hypothesis that the buoyant energy available to a parcel, in combination ...

J. M. Fritsch; C. F. Chappell

1980-08-01T23:59:59.000Z

319

Precipitation and Kinematic Structure of an Oceanic Mesoscale Convective System. Part I: Convective Line Structure  

Science Conference Proceedings (OSTI)

The precipitation, thermodynamic, and kinematic structure of an oceanic mesoscale convective system is studied using airborne Doppler and in situ (flight-level) data collected by the NOAA P-3 aircraft. The system, a well-organized, stationary, ...

David P. Jorgensen; Margaret A. LeMone; Ben Jong-Dao Jou

1991-11-01T23:59:59.000Z

320

Aerosol Indirect Effects on Tropical Convection Characteristics under Conditions of Radiative–Convective Equilibrium  

Science Conference Proceedings (OSTI)

The impacts of enhanced aerosol concentrations such as those associated with dust intrusions on the trimodal distribution of tropical convection have been investigated through the use of large-domain (10 000 grid points), fine-resolution (1 km), ...

Susan C. van den Heever; Graeme L. Stephens; Norman B. Wood

2011-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "measurement variable convection" 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

The Effects of Midlatitude Waves over and around the Tibetan Plateau on Submonthly Variability of the East Asian Summer Monsoon  

Science Conference Proceedings (OSTI)

Convective variability at submonthly time scales (7–25 days) over the Yangtze and Huaihe River basins (YHRBs) and associated large-scale atmospheric circulation during the mei-yu season were examined using interpolated outgoing longwave radiation ...

Hatsuki Fujinami; Tetsuzo Yasunari

2009-07-01T23:59:59.000Z

322

Regional Heat Sources and the Active and Break Phases of Boreal Summer Intraseasonal (30–50 Day) Variability  

Science Conference Proceedings (OSTI)

The boreal summer intraseasonal variability (BSISV) associated with the 30–50-day mode is represented by the coexistence of three components: poleward propagation of convection over the Indian and tropical west Pacific longitudes and eastward ...

H. Annamalai; K. R. Sperber

2005-08-01T23:59:59.000Z

323

Convective Building of a Pycnocline: Laboratory Experiments  

Science Conference Proceedings (OSTI)

The convective building of a pycnocline is examined using a laboratory model forced by surface fluxes of saline water at one end and fresh water at the other. A deep recirculation evolves in the tank, which homogenizes the interior fluid by ...

David W. Pierce; Peter B. Rhines

1996-02-01T23:59:59.000Z

324

A Convective Cell in a Hurricane Rainband  

Science Conference Proceedings (OSTI)

On 10 October 1983 the two NOAA WP-3D aircraft completed a mission designed to provide airborne Doppler radar data for a convective cell embedded in a weak rainband on the trailing side of Hurricane Raymond. Comparisons of the wind field produced ...

G. M. Barnes; J. F. Gamache; M. A. LeMone; G. J. Stossmeister

1991-03-01T23:59:59.000Z

325

Transport Asymmetry in Skewed Convective Circulations  

Science Conference Proceedings (OSTI)

Two simple kinematical models are used to describe the asymmetry in bottom-up and top-down diffusion in the convective boundary layer. Both models resolve the mean circulation with narrow updrafts and wider downdrafts but differ in the treatment ...

Ulrich Schumann

1993-01-01T23:59:59.000Z

326

`Convective` flat plate collectors and their applications  

SciTech Connect

The `convective` flat plate collector is a particular two-way collector system with air in gravity flow as primary working fluid. Its thermal characteristics are described. Results of outdoor tests and thermal simulations are shown. Different applications of the system are presented: water heating, steam generation for medical sterilization, solar cooking and space heating. 10 refs., 16 figs., 6 tabs.

Grupp, M.; Bergler, H.; Bertrand, J.P. [Synopsis, Lodeve (France); Kromer, B. [Institut fuer Umweltphysik der Universtaet, Heidelberg (Germany); Cieslok, J. [INCO, Aachen (Germany)

1995-12-31T23:59:59.000Z

327

A Convective Transport Theory for Surface Fluxes  

Science Conference Proceedings (OSTI)

For a boundary layer in free convection where turbulent thermal structures communicate information between the surface and the interior of the mixed layer, it is hypothesized that the surface momentum flux can be parameterized by u*2 = bDwBMML, ...

Roland B. Stull

1994-01-01T23:59:59.000Z

328

Variable Screw Compressor, Variable Screw Compressor Suppliers ...  

U.S. Energy Information Administration (EIA)

Variable Screw Compressor Suppliers & air compressor Manufacturers Directory. Source Top Quality Variable Screw Compressor Suppliers, air ...

329

Diurnal Cycle of Shallow and Deep Convection for a Tropical Land and an Ocean Environment and Its Relationship to Synoptic Wind Regimes  

Science Conference Proceedings (OSTI)

The characteristics of shallow and deep convection during the Tropical Rainfall Measuring Mission/Large-Scale Biosphere–Atmosphere Experiment in Amazonia (TRMM/LBA) and the Eastern Pacific Investigation of Climate Processes in the Coupled Ocean–...

L. Gustavo Pereira; Steven A. Rutledge

2006-10-01T23:59:59.000Z

330

Statistics of Drop Size Distribution parameters and rain rates for Stratiform and Convective precipitation during the North-Australian wet season  

Science Conference Proceedings (OSTI)

C-band polarimetric radar measurements spanning two wet seasons are used to study the effects of the large-scale environment on the statistical properties of stratiform and convective rainfall around Darwin, Australia. The rainfall physical ...

Guillaume Penide; Vickal V. Kumar; Alain Protat; Peter T. May

331

Asian Summer Monsoon Intraseasonal Variability in General Circulation Models  

SciTech Connect

The goals of this report are: (1) Analyze boreal summer Asian monsoon intraseasonal variability general circulation models--How well do the models represent the eastward and northward propagating components of the convection and how well do the models represent the interactive control that the western tropical Pacific rainfall exerts on the rainfall over India and vice-versa? (2) Role of air-sea interactions--prescribed vs. interactive ocean; and (3) Mean monsoon vs. variability.

Sperber, K R; Annamalai, H

2004-02-24T23:59:59.000Z

332

EFFECTS OF ASYMMETRIC FLOWS IN SOLAR CONVECTION ON OSCILLATION MODES  

Science Conference Proceedings (OSTI)

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

333

Mixed finite-difference/integral transform approach for parabolic-hyperbolic problems in transient forced convection  

SciTech Connect

The integral transform method is employed in conjunction with second-order-accurate explicit finite-differences schemes, to handle accurately a class of parabolic-hyperbolic problems that appear in connection with transient forced convection inside ducts. The integral transformation process eliminates the independent variables in which the diffusion phenomena predominate. A system of coupled hyperbolic equations then results, involving time and the space coordinates in which convection is dominant, which is solved numerically through a modified upwind second-order finite-difference scheme. Stability and convergence characteristics of the proposed mixed approach are also examined. Typical applications in two- and three-dimensional geometries are considered, for both slug and laminar flow situations.

Cotta, R.M.; Gerk, J.E.V. (Univ. Federal do Rio de Janeiro (Brazil). Dept. de Engenharia Mecanica)

1994-06-01T23:59:59.000Z

334

A Direct Measure of Entrainment  

Science Conference Proceedings (OSTI)

A method is introduced for directly measuring convective entrainment and detrainment in a cloud-resolving simulation. This technique is used to quantify the errors in the entrainment and detrainment estimates obtained using the standard bulk-...

David M. Romps

2010-06-01T23:59:59.000Z

335

Measurements of Sea Surface Height Variability in the Eastern South Atlantic from Pressure Sensor–Equipped Inverted Echo Sounders: Baroclinic and Barotropic Components  

Science Conference Proceedings (OSTI)

Variability in sea surface height (SSH) can be decomposed into two contributions: one from changes in mass in the water column (barotropic) and the other from purely steric changes (baroclinic). Both contributions can be determined from data ...

Sheekela Baker-Yeboah; D. Randolph Watts; Deirdre A. Byrne

2009-12-01T23:59:59.000Z

336

Convective transport in laser target plasmas  

SciTech Connect

The role of guiding-center corrections in convective transport of electron energy is examined with a simple numerical model. At 10/sup 16/W cm/sup -2/ with a 60-..mu..m spot and a 10.6-..mu..m wavelength laser, the Righi-Leduc term is observed to have little effect on transport in a calculation with the thermal flux limited to the free-streaming value.

Brackbill, J.U.; Colombant, D.; Grandjouan, N.

1982-01-01T23:59:59.000Z

337

Convective heat transport in geothermal systems  

DOE Green Energy (OSTI)

Most geothermal systems under exploitation for direct use or electrical power production are of the hydrothermal type, where heat is transferred essentially by convection in the reservoir, conduction being secondary. In geothermal systems, buoyancy effects are generally important, but often the fluid and heat flow patterns are largely controlled by geologic features (e.g., faults, fractures, continuity of layers) and location of recharge and discharge zones. During exploitation, these flow patterns can drastically change in response to pressure and temperature declines, and changes in recharge/discharge patterns. Convective circulation models of several geothermal systems, before and after start of fluid production, are described, with emphasis on different characteristics of the systems and the effects of exploitation on their evolution. Convective heat transport in geothermal fields is discussed, taking into consideration (1) major geologic features; (2) temperature-dependent rock and fluid properties; (3) fracture- versus porous-medium characteristics; (4) single- versus two-phase reservoir systems; and (5) the presence of noncondensible gases.

Lippmann, M.J.; Bodvarsson, G.S.

1986-08-01T23:59:59.000Z

338

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)

339

PROPAGATION OF GRAVITY WAVES IN A CONVECTIVE LAYER  

SciTech Connect

We perform numerical simulations of gravity mode propagation in a convective layer to investigate the observed association between small spatial scales and low frequencies in the photospheric velocity fields. According to the linear theory, when the fluid layer is convectively unstable, gravity modes are evanescent waves. However, in simple two-dimensional numerical settings, we find that when the equilibrium structure is modified by coherent large-scale convective motions, the waves injected at the bottom of the layer are no longer evanescent. In this situation, gravity waves can be detected at the surface of the layer. In our simplified model the injected wave's frequency remains unchanged, but its amplitude has a spatial modulation determined by the convective structure. This result may explain some analyses done with the proper orthogonal decomposition method of the solar surface velocity field even though solar convection is far more complex than the convection model considered here.

Onofri, M.; Vecchio, A.; Veltri, P. [Dipartimento di Fisica, Universita della Calabria, via P. Bucci, 87036 Rende (Italy); De Masi, G., E-mail: onofri@fis.unical.it [Consorzio RFX, Associazione EURATOM-ENEA sulla Fusione, 35127 Padova (Italy)

2012-02-10T23:59:59.000Z

340

Enhanced Natural Convection in a Metal Layer Cooled by Boiling Water  

Science Conference Proceedings (OSTI)

An experimental study is performed to investigate the natural convection heat transfer characteristics and the solidification of the molten metal pool concurrently with forced convective boiling of the overlying coolant to simulate a severe accident in a nuclear power plant. The relationship between the Nusselt number (Nu) and the Rayleigh number (Ra) in the molten metal pool region is determined and compared with the correlations in the literature and experimental data with subcooled water. Given the same Ra condition, the present experimental results for Nu of the liquid metal pool with coolant boiling are found to be higher than those predicted by the existing correlations or measured from the experiment with subcooled boiling. To quantify the observed effect of the external cooling on the natural convection heat transfer rate from the molten pool, it is proposed to include an additional dimensionless group characterizing the temperature gradients in the molten pool and in the external coolant region. Starting from the Globe and Dropkin correlation, engineering correlations are developed for the enhancement of heat transfer in the molten metal pool when cooled by an overlying coolant. The new correlations for predicting natural convection heat transfer are applicable to low-Prandtl-number (Pr) materials that are heated from below and solidified by the external coolant above. Results from this study may be used to modify the current model in severe accident analysis codes.

Cho, Jae-Seon [Seoul National University (Korea, Republic of); Suh, Kune Y. [Seoul National University (Korea, Republic of); Chung, Chang-Hyun [Seoul National University (Korea, Republic of); Park, Rae-Joon [Korea Atomic Energy Research Institute (Korea, Republic of); Kim, Sang-Baik [Korea Atomic Energy Research Institute (Korea, Republic of)

2004-12-15T23:59:59.000Z

Note: This page contains sample records for the topic "measurement variable convection" 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

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

342

New Insights Into Deep Convective Core Vertical Velocities Using...  

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

Insights Into Deep Convective Core Vertical Velocities Using ARM UHF Wind Profilers For original submission and image(s), see ARM Research Highlights http:www.arm.govscience...

343

Comparison between experiments and CFD predictions of mixed convection...  

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

results from a computational fluid dynamics (CFD) simulation of airflow and pollutant dispersion under mixed-convection conditions with experimental data obtained in our 7m x...

344

Thermal Convection: Patterns, Evolution and Stability by M. Lappa  

E-Print Network (OSTI)

Review of the book "Thermal Convection: Patterns, Evolution and Stability" by M. Lappa. Invited by the journal Geophysical and Astrophysical Fluid Dynamics.

Simitev, R D

2010-01-01T23:59:59.000Z

345

Drift Natural Convection and Seepage at the Yucca Mountain Repository  

E-Print Network (OSTI)

multiphase mass and heat transfer processes[26, 33], in bothdrift environment heat transfer processes are a multifacetedof convective heat transfer processes, but how is it that we

Halecky, Nicholaus Eugene

2010-01-01T23:59:59.000Z

346

A Review of Convection Initiation and Motivation for IHOP_2002  

Science Conference Proceedings (OSTI)

The International H2O Project (IHOP_2002) included four complementary research components: quantitative precipitation forecasting, convection initiation, atmospheric boundary layer processes, and instrumentation. This special issue introductory ...

Tammy M. Weckwerth; David B. Parsons

2006-01-01T23:59:59.000Z

347

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

348

The Relation between Moist Convective Adjustment Schemes and the Mass-Flux Concept for Cumulus Parameterization  

Science Conference Proceedings (OSTI)

The problem of finding convective mass fluxes and convective condensation rates in moist convective adjustment schemes for cumulus parameterization in numerical weather prediction is addressed. Formal considerations reveal that, in general, it is ...

Peter Binder

1993-12-01T23:59:59.000Z

349

The Kinematics of a Midlatitude, Continental Mesoscale Convective System and Its Mesoscale Vortex  

Science Conference Proceedings (OSTI)

The authors present a unique, scale-discriminating study of the environment-relative circulations within a mesoscale convective system (MCS) and mesoscale convective vortex (MCV). The MCS, a leading convective line and trailing stratiform region ...

Jason C. Knievel; Richard H. Johnson

2002-07-01T23:59:59.000Z

350

Analysis of Convectively Coupled Kelvin Waves in the Indian Ocean MJO  

Science Conference Proceedings (OSTI)

The active convective phase of the Madden–Julian oscillation (hereafter active MJO) comprises enhanced moist deep convection on its own temporal and spatial scales as well as increased variance in convection associated with higher-frequency ...

Paul E. Roundy

2008-04-01T23:59:59.000Z

351

Prediction of convective morphology in near-cloud permitting WRF model simulations  

Science Conference Proceedings (OSTI)

The Weather Research and Forecasting (WRF) model’s ability to forecast convective morphological evolution is examined for 37 convective systems. The simulations used Thompson microphysics with 3-km horizontal grid spacing. Ten convective mode ...

Darren V. Snively; William A. Gallus; Jr.

352

The Initiation and Evolution of Multiple Modes of Convection within a Meso-Alpha-Scale Region  

Science Conference Proceedings (OSTI)

On 30 March 2006, a convective episode occurred featuring isolated supercells, a mesoscale convective system (MCS) with parallel stratiform (PS) precipitation, and an MCS with leading stratiform (LS) precipitation. These three distinct convective ...

Adam J. French; Matthew D. Parker

2008-12-01T23:59:59.000Z

353

Structure of a Midtropospheric Vortex Induced by a Mesoscale Convective System  

Science Conference Proceedings (OSTI)

On 9 June 1988 a mesoscale (200-km diameter) convectively generated vortex (MCV) passed through the Colorado wind-profiling network. The generating convective system, which was too small to meet Maddox’s mesoscale convective complex criteria, ...

Diana L. Bartels; John M. Brown; Edward I. Tollerud

1997-02-01T23:59:59.000Z

354

Characterization of Momentum Transport Associated with Organized Moist Convection and Gravity Waves  

Science Conference Proceedings (OSTI)

Tropical convection is inherently multiscalar, involving complex fields of clouds and various regimes of convective organization ranging from small disorganized cumulus up to large organized convective clusters. In addition to being a crucial ...

Todd P. Lane; Mitchell W. Moncrieff

2010-10-01T23:59:59.000Z

355

Orogenic Convection in Subtropical South America as Seen by the TRMM Satellite  

Science Conference Proceedings (OSTI)

Extreme orogenic convective storms in southeastern South America are divided into three categories: storms with deep convective cores, storms with wide convective cores, and storms containing broad stratiform regions. Data from the Tropical ...

Kristen L. Rasmussen; Robert A. Houze Jr.

2011-08-01T23:59:59.000Z

356

Sensitivities of a Squall Line over Central Europe in a Convective-Scale Ensemble  

Science Conference Proceedings (OSTI)

Convective-scale ensemble simulations with perturbed initial and lateral boundary conditions are performed to investigate the mechanisms and sensitivities of a central European convection event from the Convective and Orographically Induced ...

K. E. Hanley; D. J. Kirshbaum; N. M. Roberts; G. Leoncini

2013-01-01T23:59:59.000Z

357

Practical and Intrinsic Predictability of Severe and Convective Weather at the Mesoscales  

Science Conference Proceedings (OSTI)

This study explores both the practical and intrinsic predictability of severe convective weather at the mesoscales using convection-permitting ensemble simulations of a squall line and bow echo event during the Bow Echo and Mesoscale Convective ...

Christopher Melhauser; Fuqing Zhang

2012-11-01T23:59:59.000Z

358

Dynamics of Orographically Triggered Banded Convection in Sheared Moist Orographic Flows  

Science Conference Proceedings (OSTI)

Shallow orographic convection embedded in an unstable cap cloud can organize into convective bands. Previous research has highlighted the important role of small-amplitude topographic variations in triggering and organizing banded convection. ...

Oliver Fuhrer; Christoph Schär

2007-10-01T23:59:59.000Z

359

Convection in a porous medium and mimetic scheme in polar coordinates  

Science Conference Proceedings (OSTI)

Analytical investigation of natural convection of the incompressible fluid in the porous media based on the Darcy hypothesis (Lapwood convection) gives intriguing branching off of one-parameter family of convective patterns. This scenario may be suppressed ...

Bülent Karasözen; Anastasia Trofimova; Vyacheslav Tsybulin

2011-09-01T23:59:59.000Z

360

Cloud-Resolving Simulations of Mesoscale Vortex Intensification and Its Effect on a Serial Mesoscale Convective System  

Science Conference Proceedings (OSTI)

The authors performed numerical simulations of the 27–28 May 1998 mesoscale convective vortex (MCV) and mesoscale convective system (MCS) to understand how the MCV modulated the convection, and how the convection intensified the vortex. The fifth-...

Christopher A. Davis; Stanley B. Trier

2002-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "measurement variable convection" 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

MESA MODELS OF CLASSICAL NOVA OUTBURSTS: THE MULTICYCLE EVOLUTION AND EFFECTS OF CONVECTIVE BOUNDARY MIXING  

SciTech Connect

Novae are cataclysmic variables driven by accretion of H-rich material onto a white dwarf (WD) star from its low-mass main-sequence binary companion. New time-domain observational capabilities, such as the Palomar Transient Factory and Pan-STARRS, have revealed a diversity of their behavior that should be theoretically addressed. Nova outbursts depend sensitively on nuclear physics data, and more readily available nova simulations are needed in order to effectively prioritize experimental effort in nuclear astrophysics. In this paper, we use the MESA stellar evolution code to construct multicycle nova evolution sequences with CO WD cores. We explore a range of WD masses and accretion rates as well as the effect of different cooling times before the onset of accretion. In addition, we study the dependence on the elemental abundance distribution of accreted material and convective boundary mixing at the core-envelope interface. Models with such convective boundary mixing display an enrichment of the accreted envelope with C and O from the underlying WD that is commensurate with observations. We compare our results with the previous work and investigate a new scenario for novae with the {sup 3}He-triggered convection.

Denissenkov, Pavel A.; Herwig, Falk [Department of Physics and Astronomy, University of Victoria, P.O. Box 3055, Victoria, BC V8W 3P6 (Canada)] [Department of Physics and Astronomy, University of Victoria, P.O. Box 3055, Victoria, BC V8W 3P6 (Canada); Bildsten, Lars; Paxton, Bill, E-mail: pavelden@uvic.ca, E-mail: fherwig@uvic.ca, E-mail: bildsten@kitp.ucsb.edu, E-mail: paxton@kitp.ucsb.edu [Kavli Institute for Theoretical Physics and Department of Physics, Kohn Hall, University of California, Santa Barbara, CA 93106 (United States)] [Kavli Institute for Theoretical Physics and Department of Physics, Kohn Hall, University of California, Santa Barbara, CA 93106 (United States)

2013-01-01T23:59:59.000Z

362

Convection with Rotation in a Neutral Ocean: A Study of Open-Ocean Deep Convection  

Science Conference Proceedings (OSTI)

The intensity and scale of the geostrophically adjusted end state of the convective overturning of a homogeneous rotating ocean of depth H at a latitude where the Coriolis parameter is f, induced by surface buoyancy loss of magnitude B0, are ...

Helen Jones; John Marshall

1993-06-01T23:59:59.000Z

363

Radiative-Convective Equilibrium with Explicit Two-Dimensional Moist Convection  

Science Conference Proceedings (OSTI)

Radiative-convective statistical equilibria are obtained using a two-dimensional model in which radiative transfer is interactive with the predicted moisture and cloud fields. The domain is periodic in x, with a width of 640 km, and extends from ...

Isaac M. Held; Richard S. Hemler; V. Ramaswamy

1993-12-01T23:59:59.000Z

364

The Wake Uw in a Midlatitude Mesoseale Convective System Having Complex Convective Organintion  

Science Conference Proceedings (OSTI)

An analysis has been carried out of the surface pressure field in a highly complex mesoscale convective system that occurred on 3-4 June 1985 during the Oklahoma-Kansas Preliminary Regional Expeximent for STORM-Central (OK PRE-STORM). During its ...

Gregory J. Stumpf; Richard H. Johnson; Bradley F. Smull

1991-01-01T23:59:59.000Z

365

Tropical Wave Instabilities: Convective Interaction with Dynamics Using the Emanuel Convective Parameterization  

Science Conference Proceedings (OSTI)

Wave-CISK and evaporation-wind feedback modes, also known as WISHE (wind-induced surface heat exchange) modes, are investigated using a two-dimensional (x?p), hydrostatic, nonrotational model linearized about a basic state in radiative-convective ...

Randy G. Brown; Christopher S. Bretherton

1995-01-01T23:59:59.000Z

366

East Asian Summer monsoon precipitation systems: rainfall characteristics, storm morphologies and convective properties.  

E-Print Network (OSTI)

??This study attempts to characterize the particular convection type, namely storm morphologies, convective properties, and microphysics, of different weather regimes within the East Asian Summer… (more)

Xu, Weixin

2011-01-01T23:59:59.000Z

367

Parameterization of Convective Precipitation in Mesoscale Numerical Models: A Critical Review  

Science Conference Proceedings (OSTI)

Current approaches for incorporating cumulus convection into mesoscale numerical models are divided into three groups. The traditional approach utilizes cumulus parameterization at convectively unstable points and explicit (nonparameterized) ...

John Molinari; Michael Dudek

1992-02-01T23:59:59.000Z

368

Experimental Investigation of Forced Convection Heat Transfer of Nanofluids in a Microchannel using Temperature Nanosensors  

E-Print Network (OSTI)

Experiments were performed to study forced convective heat transfer of de-ionized water (DI water) and aqueous nanofluids flowing in a microchannel. An array of temperature nanosensors, called “Thin Film Thermocouples (TFT)”, was utilized for performing the experimental measurements. TFT arrays were designed (which included design of photomask layout), microfabricated, packaged and assembled for testing with the experimental apparatus. Heat removal rates from the heated surface to the different testing fluids were measured by varying the coolant flow rates, wall temperatures, nanoparticle material, nanoparticle morphology (shape and nanoparticle size) as well as mass concentrations of nanoparticles in the coolants. Anomalous thermal behavior was observed in the forced convective heat transfer experiments. Precipitation of the nanoparticles on the heat exchanging surface was monitored using Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray spectroscopy (EDX). Isolated precipitation of nanoparticles is expected to cause formation of “nanofins” leading to enhancement of surface area and thus resulting in enhanced convective heat transfer to the nanofluid coolants. However, excessive precipitation (caused due to the agglomeration of the nanoparticles in the nanofluid coolant) causes scaling (fouling) of the heat exchanging surfaces and thus results in degradation of convective heat transfer. This study shows that the surface morphology plays a crucial role in determining the efficacy of convective heat transfer involving suspensions of nanoparticles in coolants (or nanofluids). Flow visualization and quantitative estimation of near-wall temperature profiles were performed using quantum dots and fluorescent dyes. This non-contact measurement technique for temperature and flow profiles in microchannels using quantum dots is expected to make pioneering contribution to the field of experimental flow visualization and to the study of micro/nano-scale heat transfer phenomena, particularly for forced convective heat transfer of various coolants, including nanofluids. Logical extensions of this study were explored and future directions were proposed. Preliminary experiments to demonstrate feasibility showed significant enhancement in the flow boiling heat flux values for nanofluids compared to that of pure solvent (DIW). Based on the novel phenomena observed in this study several other topics for future research were suggested, such as, using Surface Plasmon Resonance (SPR) platforms to monitor precipitation of nanoparticles on microchannel surfaces in real time (e.g., for generating surface isotherms).

Yu, Jiwon 1982-

2012-12-01T23:59:59.000Z

369

Sensitivity of Tropical Convection to Land Surface Processes  

Science Conference Proceedings (OSTI)

This paper studies the sensitivity of large-scale tropical convection to land surface changes in the general circulation model of the LMD. Ale method of analysis is based on a conceptual model of the energetics of convection applied every day of ...

J. Polcher

1995-09-01T23:59:59.000Z

370

Rapidly Rotating Suns and Active Nests of Convection  

E-Print Network (OSTI)

In the solar convection zone, rotation couples with intensely turbulent convection to drive a strong differential rotation and achieve complex magnetic dynamo action. Our sun must have rotated more rapidly in its past, as is suggested by observations of many rapidly rotating young solar-type stars. Here we explore the effects of more rapid rotation on the global-scale patterns of convection in such stars and the flows of differential rotation and meridional circulation which are self-consistently established. The convection in these systems is richly time dependent and in our most rapidly rotating suns a striking pattern of localized convection emerges. Convection near the equator in these systems is dominated by one or two nests in longitude of locally enhanced convection, with quiescent streaming flow in between at the highest rotation rates. These active nests of convection maintain a strong differential rotation despite their small size. The structure of differential rotation is similar in all of our more rapidly rotating suns, with fast equators and slower poles. We find that the total shear in differential rotation Delta Omega grows with more rapid rotation while the relative shear Delta Omega/Omega_0 decreases. In contrast, at more rapid rotation the meridional circulations decrease in energy and peak velocities and break into multiple cells of circulation in both radius and latitude.

Benjamin P. Brown; Matthew K. Browning; Allan Sacha Brun; Mark S. Miesch; Juri Toomre

2008-08-12T23:59:59.000Z

371

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 was influenced by strong low-level warm advection, weak vorticity advection, and weak vertical. wind shear. Its dissipation occurred as the storm encountered a more stable air mass which may have been influenced by storm induced subsidence. The cyclonic mesoscale circulation of the Mesoscale Convective Complex apparently aided in the formation of new lines of convection behind the primary convective line of the system. This process was repeated twice in the storm life cycle and led to multiple bands of convection. Indeed, this storm had three main lines: the leading line, the trailing one, and the small line near the center of the vortex. As the new lines formed, the vertical transport of momentum disrupted the symmetry of the mesovortex. However, as the line propagated eastward away from the vortex, the symmetric cyclonic circulation re-established itself. This Mesoscale Convective Complex produced flash rates in excess of 1000 h-I for twenty-four consecutive hours. The percentage of positive polarity flashes was higher during the formative and dissipating stages of the storm system. Positive flashes were also enhanced during mergers between convective bands. The flash locations during the mature stage of this storm suggest a bipolar pattern.

Valdes-Manzanilla, Arturo

1995-01-01T23:59:59.000Z

372

Gravity Waves in Shear and Implications for Organized Convection  

Science Conference Proceedings (OSTI)

It is known that gravity waves in the troposphere, which are often excited by preexisting convection, can favor or suppress the formation of new convection. Here it is shown that in the presence of wind shear or barotropic wind, the gravity waves ...

Samuel N. Stechmann; Andrew J. Majda

2009-09-01T23:59:59.000Z

373

Gravity Waves in Shear and Implications for Organized Convection  

E-Print Network (OSTI)

Gravity Waves in Shear and Implications for Organized Convection Samuel N. Stechmann Department, Los Angeles, CA 90095­1555. E-mail: stechmann@math.ucla.edu #12;ABSTRACT It is known that gravity, the gravity waves can create a more favorable environment on one side of preexisting convection than the other

Stechmann, Samuel N.

374

Boundary layer solutions for natural convection in porous media  

DOE Green Energy (OSTI)

An approximate solution is developed for natural convection in porous media resulting from localized heat sources. The method is applicable for moderate levels of convection. Results of the method compare well with those of other calculational methods and with experimental data. The solution for a spherical source can be used as an indirect method for the determination of permeability in some cases.

Hardee, H.C.

1976-05-01T23:59:59.000Z

375

Solar Convection Simulations using a B-spline method  

E-Print Network (OSTI)

This report outlines the development of a B-spline--spectral numerical code for the simulation of convection flows. It allows changing the spatial resolution in all three coordinates as a function of depth, which is especially advantageous for simulations of solar convection.

Hartlep, Thomas

2008-01-01T23:59:59.000Z

376

Solar Convection Simulations using a B-spline method  

E-Print Network (OSTI)

This report outlines the development of a B-spline--spectral numerical code for the simulation of convection flows. It allows changing the spatial resolution in all three coordinates as a function of depth, which is especially advantageous for simulations of solar convection.

Thomas Hartlep; Nagi N. Mansour

2008-05-05T23:59:59.000Z

377

Environmental Distinctions between Cellular and Slabular Convective Lines  

Science Conference Proceedings (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

378

Climatic regimes of tropical convection and rainfall  

SciTech Connect

Annual distribution and phase propagation of tropical convection are delineated using harmonic and amplitude-phase characteristics analysis of climatological pentad mean outgoing longwave radiation and monthly frequencies of highly reflective cloud. An annual eastward propagation of peak rainy season along the equator from the central Indian Ocean (60[degrees]E) to Arafura Sea (130[degrees]E) is revealed. This indicates a transition from the withdrawal of the Indian summer monsoon to the onset of the Australian summer monsoon. Significant bimodal variations are found around major summer monsoon regions. These variations originate from the interference of two adjacent regimes. The convergence zones over the eastern North Pacific, the South Pacific, and the southwest Indian Ocean are identified as a marine monsoon regime that is characterized by a unimodal variation with a concentrated summer rainfall associated with the development of surface westerlies equatorward of a monsoon trough. Conversely, the central North Pacific and North Atlantic convergence zones between persistent northeast and southeast trades are classified as trade-wind convergence zones; which differ from the marine monsoon regime by their persistent rainy season and characteristic bimodal variation with peak rainy seasons occurring in late spring and fall. The roles of the annual march of sea surface temperature in the phase propagation and formation of various climatic regimes of tropical convection are also discussed. 34 refs., 8 figs., 1 tab.

Wang, Bin (Univ. of Hawaii, Honolulu, HI (United States))

1994-07-01T23:59:59.000Z

379

A MOLTEN SALT NATURAL CONVECTION REACTOR SYSTEM  

SciTech Connect

Fuel-salt volumes external to the core of a molten-salt reactor are calculated for a system in which the fuel salt circulates through the core and primary exchanger by free convection. In the calculation of these volumes, the exchanger heights above the core top range from 5 to 20 ft. Coolants considered for the primary exchanger are a second molten salt and helium. External fuel holdup is found to be the same with either coolant. Two sets of terminal temperatures are selected for the helium. The first combination permits steam generation at 850 psia, 900 deg F. The second set is selected for a closed gas turbine cycle with an 1100 deg F turbine inlet temperature. Specific power (thermal kw/kg 235) is found to be about 900 Mv/kg, based on initial, clean conditions and a 60 Mw (thermal) output. A specific power of 1275 kw/kg is estimated for a forced convection system of the same rating. (auth)

Romie, F.E.; Kinyon, B.W.

1958-02-01T23:59:59.000Z

380

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-

Note: This page contains sample records for the topic "measurement variable convection" 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

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,

382

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

383

Convective heat transfer in the laminar-turbulent transition region with molten salt in a circular tube  

SciTech Connect

In order to understand the heat transfer characteristics of molten salt and testify the validity of the well-known empirical convective heat transfer correlations, experimental study on transition convective heat transfer with molten salt in a circular tube was conducted. Molten salt circulations were realized and operated in a specially designed system over 1000 h. The average forced convective heat transfer coefficients of molten salt were determined by least-squares method based on the measured data of flow rates and temperatures. Finally, a heat transfer correlation of transition flow with molten salt in a circular tube was obtained and good agreement was observed between the experimental data of molten salt and the well-known correlations presented by Hausen and Gnielinski, respectively. (author)

Yu-ting, Wu; Bin, Liu; Chong-fang, Ma; Hang, Guo [Key Laboratory of Enhanced Heat Transfer and Energy Conservation, Ministry of Education and Key Laboratory of Heat Transfer and Energy Conversion, Beijing municipality, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100022 (China)

2009-10-15T23:59:59.000Z

384

Effects of Varying the Shape of the Convective Heating Profile on Convectively Coupled Gravity Waves and Moisture Modes  

Science Conference Proceedings (OSTI)

The analytical model of convectively coupled gravity waves and moisture modes of Raymond and Fuchs is extended to the case of top-heavy and bottom-heavy convective heating profiles. Top-heavy heating profiles favor gravity waves, while bottom-...

Željka Fuchs; Saska Gjorgjievska; David J. Raymond

2012-08-01T23:59:59.000Z

385

Comparison of the Diurnal Precipitation Cycle in Convection-Resolving and Non-Convection-Resolving Mesoscale Models  

Science Conference Proceedings (OSTI)

The diurnal cycles of rainfall in 5-km grid-spacing convection-resolving and 22-km grid-spacing non-convection-resolving configurations of the Weather Research and Forecasting (WRF) model are compared to see if significant improvements can be ...

Adam J. Clark; William A. Gallus Jr.; Tsing-Chang Chen

2007-10-01T23:59:59.000Z

386

Long-Term Simulations of Thermally Driven Flows and Orographic Convection at Convection-Parameterizing and Cloud-Resolving Resolutions  

Science Conference Proceedings (OSTI)

The purpose of this paper is to validate the representation of topographic flows and moist convection over the European Alps in a convection-parameterizing simulation (CPM; ?x = 6.6 km) and two cloud-resolving simulations (CRM; ?x = 1.1 and 2.2 km)...

Wolfgang Langhans; Juerg Schmidli; Oliver Fuhrer; Susanne Bieri; Christoph Schär

2013-06-01T23:59:59.000Z

387

Three-dimensional, transient natural convection in inclined wellbores  

SciTech Connect

The occurrence of natural conduction in a wellbore can affect geothermal gradient measurements and heat flow estimates. In the Hot Dry Rock geothermal concept, the wellbores are purposely inclined in the deep regions to enhance heat production. To simulate natural convection flow patterns in directionally drilled wellbores, experiments and analyses were conducted for a circular tube with length to diameter (L/D) ratio of 36 at angles of 0{degrees}, 20{degrees}, and 35{degrees} from the vertical. The tube was heated at the bottom and cooled at the top, and the insulation was adjusted so that approximately one- to two-thirds of the power dissipated was transferred through the tube wall to the surroundings. An aqueous solution of polyvinyl alcohol was employed as the working fluid in order to obtain low Rayleigh numbers corresponding to conditions in geothermal wellbores. Temperature distributions were measured for the three orientations and for several heating rates to demonstrate the effects of tube angle and Rayleigh number. Comparison with measurements showed good agreement of the predicted temperature levels for the maximum inclination and slightly poorer agreement for the other limit, a vertical tube. 50 refs., 9 figs.

McEligot, D.M. (Westinghouse Electric Corp., Middletown, RI (USA). Oceanic Div.); Denbow, D.A. (Software AG of North America, Inc., Lakewood, CO (USA)); Murphy, H.D. (Los Alamos National Lab., NM (USA))

1990-01-01T23:59:59.000Z

388

Sources of Errors in Rainfall Measurements by Polarimetric Radar: Variability of Drop Size Distributions, Observational Noise, and Variation of Relationships between R and Polarimetric Parameters  

Science Conference Proceedings (OSTI)

Using a set of long-term disdrometric data and of actual radar measurements from the McGill S-band operational polarimetric radar, several sources of errors in rain measurement with polarimetric radar are explored in order to investigate their ...

Gyu Won Lee

2006-08-01T23:59:59.000Z

389

FLUX EMERGENCE IN A MAGNETIZED CONVECTION ZONE  

Science Conference Proceedings (OSTI)

We study the influence of a dynamo magnetic field on the buoyant rise and emergence of twisted magnetic flux ropes and their influence on the global external magnetic field. We ran three-dimensional MHD numerical simulations using the ASH code (anelastic spherical harmonics) and analyzed the dynamical evolution of such buoyant flux ropes from the bottom of the convection zone until the post-emergence phases. The global nature of this model can only very crudely and inaccurately represent the local dynamics of the buoyant rise of the implanted magnetic structure, but nonetheless allows us to study the influence of global effects, such as self-consistently generated differential rotation and meridional circulation, and of Coriolis forces. Although motivated by the solar context, this model cannot be thought of as a realistic model of the rise of magnetic structures and their emergence in the Sun, where the local dynamics are completely different. The properties of initial phases of the buoyant rise are determined essentially by the flux-rope's properties and the convective flows and consequently are in good agreement with previous studies. However, the effects of the interaction of the background dynamo field become increasingly strong as the flux ropes evolve. During the buoyant rise across the convection zone, the flux-rope's magnetic field strength scales as B{proportional_to}{rho}{sup {alpha}}, with {alpha} {approx}current density is observed to precede flux emergence at all longitudes. The geometry, latitude, and relative orientation of the flux ropes with respect to the background magnetic field influences the resulting rise speeds, zonal flow amplitudes (which develop within the flux ropes), and the corresponding surface signatures. This influences the morphology, duration and amplitude of the surface shearing, and the Poynting flux associated with magnetic flux-rope emergence. The emerged magnetic flux influences the system's global polarity, leading in some cases to a polarity reversal while inhibiting the background dynamo from doing so in others. The emerged magnetic flux is slowly advected poleward while being diffused and assimilated by the background dynamo field.

Pinto, R. F.; Brun, A. S., E-mail: rui.pinto@cea.fr [Laboratoire AIM Paris-Saclay, CEA/Irfu Universite Paris-Diderot CNRS/INSU, F-91191 Gif-sur-Yvette (France)

2013-07-20T23:59:59.000Z

390

Reflections on dissipation associated with thermal convection  

E-Print Network (OSTI)

Buoyancy-driven convection is modelled using the Navier-Stokes and entropy equations. It is first shown that the coefficient of heat capacity at constant pressure, c_p, must in general depend explicitly on pressure (i.e. is not a function of temperature alone) in order to resolve a dissipation inconsistency. It is shown that energy dissipation in a statistically steady state is the time-averaged volume integral of - (D P)/(D t) and not that of - alpha T (D P)/(D t). Secondly, in the framework of the anelastic equations derived with respect to the adiabatic reference state, we obtain a condition when the anelastic liquid approximation can be made, gamma -1 << 1, independent of the dissipation number.

Thierry Alboussiere; Yanick Ricard

2012-10-19T23:59:59.000Z

391

Inside the supernova a powerful convective engine  

E-Print Network (OSTI)

We present an extensive study of the inception of supernova explosions by following the evolution of the cores of two massive stars (15 Msun and 25 Msun) in two dimensions. Our calculations begin at the onset of core collapse and stop several 100 ms after the bounce, at which time successful explosions of the appropriate magnitude have been obtained. (...) Guided by our numerical results, we have developed a paradigm for the supernova explosion mechanism. We view a supernova as an open cycle thermodynamic engine in which a reservoir of low-entropy matter (the envelope) is thermally coupled and physically connected to a hot bath (the protoneutron star) by a neutrino flux, and by hydrodynamic instabilities. (...) In essence, a Carnot cycle is established in which convection allows out-of-equilibrium heat transfer mediated by neutrinos to drive low entropy matter to higher entropy and therefore extracts mechanical energy from the heat generated by gravitational collapse. We argue that supernova explosions are ne...

Herant, M; Hix, W R; Fryer, C F; Colgate, S A; Marc Herant; Willy Benz; Chris F Fryer; Stirling Colgate

1994-01-01T23:59:59.000Z

392

Inside the Supernova: A Powerful Convective Engine  

E-Print Network (OSTI)

Condensed Abstract: We present an extensive study of the inception of supernova explosions by following the evolution of the cores of two massive stars (15 Msun and 25 Msun) in two dimensions. Our calculations begin at the onset of core collapse and stop several 100 ms after the bounce, at which time successful explosions of the appropriate magnitude have been obtained. (...) Guided by our numerical results, we have developed a paradigm for the supernova explosion mechanism. We view a supernova as an open cycle thermodynamic engine in which a reservoir of low-entropy matter (the envelope) is thermally coupled and physically connected to a hot bath (the protoneutron star) by a neutrino flux, and by hydrodynamic instabilities. (...) In essence, a Carnot cycle is established in which convection allows out-of-equilibrium heat transfer mediated by neutrinos to drive low entropy matter to higher entropy and therefore extracts mechanical energy from the heat generated by gravitational collapse. We argue that supernova explosions are nearly guaranteed and self-regulated by the high efficiency of the thermodynamic engine. (...) Convection continues to accumulate energy exterior to the neutron star until a successful explosion has occurred. At this time, the envelope is expelled and therefore uncoupled from the heat source (the neutron star) and the energy input ceases. This paradigm does not invoke new or modified physics over previous treatments, but relies on compellingly straightforward thermodynamic arguments. It provides a robust and self-regulated explosion mechanism to power supernovae which is effective under a wide range of physical parameters.

Marc Herant; Willy Benz; W. Raphael Hix; Chris F. Fryer; Stirling Colgate

1994-04-12T23:59:59.000Z

393

Double Diffusive Natural Convection in a Nuclear Waste Repository  

Science Conference Proceedings (OSTI)

In this study, we conduct a two-dimensional numerical analysis of double diffusive natural convection in an emplacement drift for a nuclear waste repository. In-drift heat and moisture transport is driven by combined thermal- and compositional-induced buoyancy forces. Numerical results demonstrate buoyancy-driven convective flow patterns and configurations during both repository heat-up and cool-down phases. It is also shown that boundary conditions, particularly on the drip-shield surface, have strong impacts on the in-drift convective flow and transport.

Y. Hao; J. Nitao; T.A. Buscheck; Y. Sun

2006-03-28T23:59:59.000Z

394

Simulated Convective Lines with Leading Precipitation. Part I: Governing Dynamics  

Science Conference Proceedings (OSTI)

This article, the first of two describing a study in which the authors used idealized numerical simulations to investigate convective lines with leading precipitation, addresses the dynamics governing the systems' structures and individual air ...

Matthew D. Parker; Richard H. Johnson

2004-07-01T23:59:59.000Z

395

The Onset of Convection in the Madden–Julian Oscillation  

Science Conference Proceedings (OSTI)

An observational study of the onset of convection in the Madden–Julian oscillation (MJO) was performed. Composites of radiosonde data from the Comprehensive Aerological Reference Data Set were constructed for an ensemble of tropical stations ...

Susan R. Kemball-Cook; Bryan C. Weare

2001-03-01T23:59:59.000Z

396

Convective Boundary Layers Driven by Nonstationary Surface Heat Fluxes  

Science Conference Proceedings (OSTI)

In this study the response of dry convective boundary layers to nonstationary surface heat fluxes is systematically investigated. This is relevant not only during sunset and sunrise but also, for example, when clouds modulate incoming solar ...

Robert van Driel; Harm J. J. Jonker

2011-04-01T23:59:59.000Z

397

On the Generation of Convectively Driven Mesohighs Aloft  

Science Conference Proceedings (OSTI)

In an attempt to determine the relative contribution of the direct incorporation of cold air (detrainment from overshooting convective cloud tops) to the production of mesohighs in the vicinity of the tropopause, two numerical simulations were ...

J. M. Fritsch; J. M. Brown

1982-11-01T23:59:59.000Z

398

Mesoscale Convective Complexes in the Western Pacific Region  

Science Conference Proceedings (OSTI)

A climatological study of mesoscale convective complexes (MCCs) during 1983–1985 over the western Pacific region (WPR), using full-disc, enhanced infrared satellite imagery from the Japanese Geostationary Meteorological Satellite is presented.

David Miller; J. M. Fritsch

1991-12-01T23:59:59.000Z

399

Mesoscale Convective Complexes over the Indian Monsoon Region  

Science Conference Proceedings (OSTI)

Full disk infrared satellite imagery from the Indian National Satellite System (INSAT) geostationary meteorological satellite was examined to determine if mesoscale convective complexes (MCCs) frequent the Indian subcontinent (ISC) region. Using ...

Arlenf G. Laing; J. Michael Fritsch

1993-05-01T23:59:59.000Z

400

Resolution Requirements for the Simulation of Deep Moist Convection  

Science Conference Proceedings (OSTI)

The spatial resolution appropriate for the simulation of deep moist convection is addressed from a turbulence perspective. To provide a clear theoretical framework for the problem, techniques for simulating turbulent flows are reviewed, and the ...

George H. Bryan; John C. Wyngaard; J. Michael Fritsch

2003-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "measurement variable convection" 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

Impact of Stochastic Convection on the Ensemble Transform  

Science Conference Proceedings (OSTI)

The impact of stochastic convection on ensembles produced using the ensemble transform (ET) initial perturbation scheme is examined. This note compares the behavior of ensemble forecasts based only on initial ET perturbations with the behavior of ...

Carolyn A. Reynolds; Joao Teixeira; Justin G. McLay

2008-11-01T23:59:59.000Z

402

Tropical Convection and Precipitation Regimes in the Western United States  

Science Conference Proceedings (OSTI)

The authors have documented the relationship between tropical convection and precipitation regimes in the western United States. Circulation patterns associated with precipitation regimes are described and physical mechanisms are proposed. ...

Kingtse C. Mo; R. W. Higgins

1998-09-01T23:59:59.000Z

403

On the Relationship between Tropical Convection and Sea Surface Temperature  

Science Conference Proceedings (OSTI)

Tropical observations show convective activity increasing sharply above sea surface temperatures (SSTs) of around 26°C and then decreasing as the SST exceeds 30°C, with maximum observed SSTs of around 32°C.Although some aspects of this ...

Adrian M. Tompkins

2001-03-01T23:59:59.000Z

404

Precipitation Efficiency of Warm-Season Midwestern Mesoscale Convective Systems  

Science Conference Proceedings (OSTI)

The precipitation efficiencies for mesoscale convective systems (MCS) over the central United States are calculated. During July–September 2000 and June–September 2001, 24 MCS for which sufficient data were available occurred over or near ...

Patrick Market; Stacy Allen; Roderick Scofield; Robert Kuligowski; Arnold Gruber

2003-12-01T23:59:59.000Z

405

The Environments of Significant Convective Events in the Western Mediterranean  

Science Conference Proceedings (OSTI)

The environmental characteristics associated with 313 significant convective events in the western Mediterranean are investigated using radiosonde ascents made in Mallorca (Spain). The events are separated into five groups, based on the observed ...

Elisa Tudurí; Clemente Ramis

1997-06-01T23:59:59.000Z

406

Frontogenesis in the Presence of Small Stability to Slantwise Convection  

Science Conference Proceedings (OSTI)

It is often observed that, despite the existence of near neutrality to slantwise convection, rainbands and snowbands can persist for long periods with narrow intense updrafts producing large quantities of precipitation in many cases. This is ...

A. J. Thorpe; K. A. Emanuel

1985-09-01T23:59:59.000Z

407

Survey and evaluation of techniques to augment convective heat transfer  

E-Print Network (OSTI)

This report presents a survey and evaluation of the numerous techniques which have been shown to augment convective heat transfer. These techniques are: surface promoters, including roughness and treatment; displaced ...

Bergles A. E.

1965-01-01T23:59:59.000Z

408

Multiple Convection Patterns and Thermohaline Flow in an Idealized OGCM  

Science Conference Proceedings (OSTI)

This paper investigates how multiple steady states arise in an ocean general circulation model, caused by the fact that many different convection patterns can be stable under the same surface boundary conditions. Two alternative boundary ...

Stefan Rahmstorf

1995-12-01T23:59:59.000Z

409

Factors for the Simulation of Convectively Coupled Kelvin Waves  

Science Conference Proceedings (OSTI)

This study investigates the major factors for the realistic simulation of convectively coupled Kelvin waves (CCKWs) using the National Centers for Environmental Prediction (NCEP) Climate Forecast System (CFS) models. CFS simulations employing ...

Kyong-Hwan Seo; Jin-Ho Choi; Sang-Dae Han

2012-05-01T23:59:59.000Z

410

Convective Precursors and Predictability in the Tropical Western Pacific  

Science Conference Proceedings (OSTI)

Conditions leading to convective outbreak in the Tropics are investigated by multivariate analysis of sounding and satellite data from the tropical western Pacific area. Circumstances that make the prediction problem difficult are discussed and ...

Steven C. Sherwood

1999-12-01T23:59:59.000Z

411

An Observational Study of Derecho-Producing Convective Systems  

Science Conference Proceedings (OSTI)

This study identifies the common large-scale environments associated with the development of derecho- producing convective systems (DCSs) from a large number of events. Patterns are identified using statistical clustering of the 500-mb ...

Michael C. Coniglio; David J. Stensrud; Michael B. Richman

2004-04-01T23:59:59.000Z

412

A Large Eddy Simulation Intercomparison Study of Shallow Cumulus Convection  

Science Conference Proceedings (OSTI)

This paper reports an intercomparison study on undisturbed trade wind cumulus convection under steady-state conditions as observed during the Barbados Oceanographic and Meteorological Experiment (BOMEX) with 10 large eddy simulation (LES) models. ...

A. Pier Siebesma; Christopher S. Bretherton; Andrew Brown; Andreas Chlond; Joan Cuxart; Peter G. Duynkerke; Hongli Jiang; Marat Khairoutdinov; David Lewellen; Chin-Hoh Moeng; Enrique Sanchez; Bjorn Stevens; David E. Stevens

2003-05-01T23:59:59.000Z

413

Analysis of Convection and Its Association with African Easterly Waves  

Science Conference Proceedings (OSTI)

The association between convection and African easterly wave (AEW) activity over tropical Africa and the tropical Atlantic during the boreal summer is examined using satellite brightness temperature (TB) and ECMWF reanalysis datasets. Spectral ...

Ademe Mekonnen; Chris D. Thorncroft; Anantha R. Aiyyer

2006-10-01T23:59:59.000Z

414

Convection-Evaporation Feedback in the Equatorial pacific  

Science Conference Proceedings (OSTI)

The coupling between convection and surface evaporation is investigated to assess the importance of evaporative cooling in regulating the tropical sea surface temperature. It is found that such a coupling is scale dependent. On timescales of ...

Guang Jun Zhang; V. Ramanathan; Michael J. McPhaden

1995-12-01T23:59:59.000Z

415

Eddy Modulation of Air–Sea Interaction and Convection  

Science Conference Proceedings (OSTI)

Eddy modulation of the air–sea interaction and convection that occurs in the process of mode water formation is analyzed in simulations of a baroclinically unstable wind- and buoyancy-driven jet. The watermass transformation analysis of Walin is ...

Ivana Cerove?ki; John Marshall

2008-01-01T23:59:59.000Z

416

A Linearized Convective Overturning Model for Prediction of Thunderstorm Movement  

Science Conference Proceedings (OSTI)

A linearized model of convective overturning in shear for prediction of storm propagation is presented. Good correspondence between the model and observation is found for a number of case studies of real storms. Supercell storms, however, are an ...

Adrian Marroquin; David J. Raymond

1982-01-01T23:59:59.000Z

417

Observational Analysis of the Predictability of Mesoscale Convective Systems  

Science Conference Proceedings (OSTI)

Mesoscale convective systems (MCSs) have a large influence on the weather over the central United States during the warm season by generating essential rainfall and severe weather. To gain insight into the predictability of these systems, the ...

Israel L. Jirak; William R. Cotton

2007-08-01T23:59:59.000Z

418

Equatorial Atmospheric Waves and Their Association to Convection  

Science Conference Proceedings (OSTI)

Equatorial wave systems and their relationships with convective activity are analyzed in the western and central Pacific regions during the Coupled Ocean–Atmosphere Response Experiment (COARE) intensive observation periods. The study uses ...

P. Pires; J-L. Redelsperger; J-P. Lafore

1997-06-01T23:59:59.000Z

419

A Stereo Photogrammetric Technique Applied to Orographic Convection  

Science Conference Proceedings (OSTI)

This paper describes a technique for photogrammetric analysis of stereo pairs of images that is applied to the study of orographic convection. The technique is designed for use with digital images and assumes detailed knowledge of the camera ...

Joseph A. Zehnder; Jiuxiang Hu; Anshuman Razdan

2007-06-01T23:59:59.000Z

420

Toward Convective Boundary Layer Parameterization: A Scalar Transport Module  

Science Conference Proceedings (OSTI)

Recent results from large-eddy simulations indicate that the eddy diffusivity for scalar diffusion through the top of a convective boundary layer is different from that for diffusion through the bottom. From this, one can show that the eddy ...

John C. Wyngaard

1984-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "measurement variable convection" 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

An Observational Analysis of a Developing Mesoscale Convective Complex  

Science Conference Proceedings (OSTI)

Dual-Doppler radar, surface mesonet, satellite, and upper-air sounding data from the 1985 Preliminary Regional Experiment for STORM-Central field experiment are used to analyze the early growth stages of a mesoscale convective complex (MCC) that ...

Jason E. Nachamkin; Ray L. McAnelly; William R. Cotton

1994-06-01T23:59:59.000Z

422

Transitions in Shallow Convection: An Explanation for Lateral Cell Expansion  

Science Conference Proceedings (OSTI)

A generalized seven-coefficient model of two-dimensional Rayleigh-Bénard convection is presented. The model simulates successfully one means by which lateral cell expansion can occur as the value of the imposed vertical temperature difference is ...

Hai-Ru Chang; Hampton N. Shirer

1984-08-01T23:59:59.000Z

423

Positive Cloud-to-Ground Lightning in Mesoscale Convective Systems  

Science Conference Proceedings (OSTI)

We have examined the characteristics of positive cloud-to-ground lightning flashes in Mesoscale Convective Systems observed during the Oklahoma-Kansas PRE-STORM project in 1985. Lightning frequencies and patterns of ground strike locations are ...

Steven A. Rutledge; Chungu Lu; Donald R. MacGorman

1990-09-01T23:59:59.000Z

424

Equatorial Wave Activity Derived from Fluctuations in Observed Convection  

Science Conference Proceedings (OSTI)

The spectrum of equatorial wave activity propagating vertically into the stratosphere is calculated from high-resolution imagery of the global convective pattern. Synoptic Global Cloud Imagery (GCI), constructed from six satellites simultaneously ...

John W. Bergman; Murry L. Salby

1994-12-01T23:59:59.000Z

425

The Influence of Helicity on Numerically Simulated Convective Storms  

Science Conference Proceedings (OSTI)

A three-dimensional numerical cloud model is used to investigate the influence of storm-relative environmental helicity (SREH) on convective storm structure and evolution, with a particular emphasis on the identification of ambient shear profiles ...

Kelvin K. Droegemeier; Steven M. Lazarus; Robert Davies-Jones

1993-07-01T23:59:59.000Z

426

Further Aspects of Transitions in Two-Dimensional Thermal Convection  

Science Conference Proceedings (OSTI)

In this paper we present the results of numerical investigation of a two-dimensional nonlinear set of Boussinesq equations governing Bénard–Rayleigh convection using spectral representation in the horizontal direction and finite-difference ...

Marina Zivkovi?; Ernest M. Agee

1988-12-01T23:59:59.000Z

427

Observations from Space and Thermal Convection: A Historical Perspective  

Science Conference Proceedings (OSTI)

An abbreviated historical account of the evolution of the satellite meteorology program is presented. Emphasis is placed on the importance of the satellite and its space platform for observing and studying atmospheric convection. Particular ...

Ernest M. Agee

1984-09-01T23:59:59.000Z

428

Wavelet-Compressed Representation of Deep Moist Convection  

Science Conference Proceedings (OSTI)

The capacity of wavelets to effectively represent atmospheric processes under compression is tested by a dataset generated by a cloud-resolving model simulation of deep convective events observed during the Tropical Ocean Global Atmosphere ...

Jun-Ichi Yano; Peter Bechtold; Jean-Luc Redelsperger; Francoise Guichard

2004-06-01T23:59:59.000Z

429

Effects of Rotation on Convective Plumes from Line Segment Sources  

Science Conference Proceedings (OSTI)

Effects of rotation on finite-length line plumes are studied with a three-dimensional nonhydrostatic numerical model. Geophysical convection with this source geometry occurs, for example, as the result of fissure releases of hot hydrothermal ...

J. W. Lavelle; D. C. Smith IV

1996-06-01T23:59:59.000Z

430

VARIATION OF STELLAR ENVELOPE CONVECTION AND OVERSHOOT WITH METALLICITY  

SciTech Connect

We examine how metallicity affects convection and overshoot in the superadiabatic layer of main sequence stars. We present results from a grid of three-dimensional radiation hydrodynamic simulations with four metallicities (Z = 0.040, 0.020, 0.010, 0.001), and spanning a range in effective temperature (4950 < T{sub eff} < 6230). We show that changing the metallicity alters properties of the convective gas dynamics, and the structure of the superadiabatic layer and atmosphere. Our grid of simulations shows that the amount of superadiabaticity, which tracks the transition from efficient to inefficient convection, is sensitive to changes in metallicity. We find that increasing the metallicity forces the location of the transition region to lower densities and pressures, and results in larger mean and turbulent velocities throughout the superadiabatic region. We also quantify the degree of convective overshoot in the atmosphere, and show that it increases with metallicity as well.

Tanner, Joel D.; Basu, Sarbani; Demarque, Pierre [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520-8101 (United States)] [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520-8101 (United States)

2013-04-10T23:59:59.000Z

431

Stratospheric Gravity Waves Generated by Multiscale Tropical Convection  

Science Conference Proceedings (OSTI)

The generation of gravity waves by multiscale cloud systems evolving in an initially motionless and thermodynamically uniform environment is explored using a two-dimensional cloud-system-resolving model. The simulated convection has similar depth ...

Todd P. Lane; Mitchell W. Moncrieff

2008-08-01T23:59:59.000Z

432

Organizational Modes of Mesoscale Convective Systems over Central East China  

Science Conference Proceedings (OSTI)

Composite reflectivity Doppler radar data from June to September of 2007--2010 were used to classify mesoscale convective systems (MCSs) over Central East China into seven morphologies. The morphologies included one nonlinear mode (NL) and six ...

Linlin Zheng; Jianhua Sun; Xiaoling Zhang; Changhai Liu

433

A Climatology of Fatal Convective Wind Events by Storm Type  

Science Conference Proceedings (OSTI)

There are still hundreds of casualties produced by thunderstorm hazards each year in the United States despite the many recent advances in prediction and mitigation of the effects of convective storms. Of the four most common thunderstorm hazards ...

Joseph M. Schoen; Walker S. Ashley

2011-02-01T23:59:59.000Z

434

Extreme Helicity and Intense Convective Towers in Hurricane Bonnie  

Science Conference Proceedings (OSTI)

Helicity was calculated in Hurricane Bonnie (1998) using tropospheric-deep dropsonde soundings from the NASA Convection and Moisture Experiment. Large helicity existed downshear of the storm center with respect to the ambient vertical wind shear. ...

John Molinari; David Vollaro

2008-11-01T23:59:59.000Z

435

Influence of Bulk Convection on Freckle Formation in Castings  

Science Conference Proceedings (OSTI)

compartments, a hot zone and a cold zone as shown in Figure l(a) below. A baffle is used to .... that the bulk convection cell will not distort the flow at the inlet.

436

Representing Convective Organization in Prediction Models by a Hybrid Strategy  

Science Conference Proceedings (OSTI)

The mesoscale organization of precipitating convection is highly relevant to next-generation global numerical weather prediction models, which will have an intermediate horizontal resolution (grid spacing about 10 km). A primary issue is how to ...

Mitchell W. Moncrieff; Changhai Liu

2006-12-01T23:59:59.000Z

437

A Stochastic Parameterization for Deep Convection Based on Equilibrium Statistics  

Science Conference Proceedings (OSTI)

A stochastic parameterization scheme for deep convection is described, suitable for use in both climate and NWP models. Theoretical arguments and the results of cloud-resolving models are discussed in order to motivate the form of the scheme. In ...

R. S. Plant; G. C. Craig

2008-01-01T23:59:59.000Z

438

The Kain–Fritsch Convective Parameterization: An Update  

Science Conference Proceedings (OSTI)

Numerous modifications to the Kain–Fritsch convective parameterization have been implemented over the last decade. These modifications are described, and the motivating factors for the changes are discussed. Most changes were inspired by feedback ...

John S. Kain

2004-01-01T23:59:59.000Z

439

Another Look at the Thermodynamic Equation For Deep Convection  

Science Conference Proceedings (OSTI)

The study considers deep moist convection involving only a liquid-vapor phase change. An alternative form of the classical thermodynamic equation for reversible saturated flow is derived. Four approximate forms of this equation are obtained and ...

Frank B. Lipps; Richard S. Hemler

1980-01-01T23:59:59.000Z

440

Analytical Parameterizations of Diffusion: The Convective Boundary Layer  

Science Conference Proceedings (OSTI)

A brief review is made of data bases which have been used for developing diffusion parameterizations for the convective boundary layer (CBL). A variety of parameterizations for lateral and vertical dispersion, ?y and ?z, are surveyed; some of ...

Gary A. Briggs

1985-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "measurement variable convection" 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

The “Footprint” under a Decaying Tropical Mesoscale Convective System  

Science Conference Proceedings (OSTI)

On 10 February 1993, during the Tropical Ocean Global Atmosphere Coupled Ocean–Atmosphere Response Experiment, the two NOAA WP-3Ds and the NCAR Electra flew under the anvil region of a decaying mesoscale convective system (MCS). Satellite and ...

Mark F. Geldmeier; Gary M. Barnes

1997-11-01T23:59:59.000Z

442

Satellite and Radar Survey of Mesoscale Convective System Development  

Science Conference Proceedings (OSTI)

An investigation of several hundred mesoscale convective systems (MCSs) during the warm seasons (April–August) of 1996–98 is presented. Circular and elongated MCSs on both the large and small scales were classified and analyzed in this study ...

Israel L. Jirak; William R. Cotton; Ray L. McAnelly

2003-10-01T23:59:59.000Z

443

Wintertime Convection in a Gulf stream Warm Core Ring  

Science Conference Proceedings (OSTI)

Wintertime convection creates deep mixed layers which determine the water mass characteristics and potential vorticity for waters in the main pycnocline of the world ocean. Diabatic cooling is most intense in the Northern Hemisphere near the ...

Terrence M. Joyce; Marvel C. Stalcup

1985-08-01T23:59:59.000Z

444

An Investigation of Turbulence Generation Mechanisms above Deep Convection  

Science Conference Proceedings (OSTI)

An investigation of the generation of turbulence above deep convection is presented. This investigation is motivated by an encounter between a commercial passenger aircraft and severe turbulence above a developing thunderstorm near Dickinson, ...

Todd P. Lane; Robert D. Sharman; Terry L. Clark; Hsiao-Ming Hsu

2003-05-01T23:59:59.000Z

445

Dynamic Radiative–Convective Equilibria Using GCM Column Physics  

Science Conference Proceedings (OSTI)

The behavior of a GCM column physics package in a nonrotating, doubly periodic, homogeneous setting with prescribed SSTs is examined. This radiative–convective framework is proposed as a useful tool for studying some of the interactions between ...

Isaac M. Held; Ming Zhao; Bruce Wyman

2007-01-01T23:59:59.000Z

446

Numerical Modeling of Gravity Wave Generation by Deep Tropical Convection  

Science Conference Proceedings (OSTI)

Although convective clouds are known to generate internal gravity waves, the mechanisms responsible are not well understood. The present study seeks to clarify the dynamics of wave generation using a high-resolution numerical model of deep ...

Todd P. Lane; Michael J. Reeder; Terry L. Clark

2001-05-01T23:59:59.000Z

447

RESEARCH CAMPAIGN: The Convective and Orographically Induced Precipitation Study  

Science Conference Proceedings (OSTI)

The international field campaign called the Convective and Orographically-induced Precipitation Study (COPS) took place from June to August 2007 in southwestern Germany/eastern France. The overarching goal of COPS is to advance the quality of ...

Volker Wulfmeyer; Andreas Behrendt; Hans-Stefan Bauer; Christoph Kottmeier; Ulrich Corsmeier; Alan Blyth; George Craig; Ulrich Schumann; Martin Hagen; Susanne Crewell; Paolo Di Girolamo; Cyrille Flamant; Mark Miller; Andrea Montani; Stephen Mobbs; Evelyne Richard; Mathias W. Rotach; Marco Arpagaus; Herman Russchenberg; Peter Schlüssel; Marianne König; Volker Gärtner; Reinhold Steinacker; Manfred Dorninger; David D. Turner; Tammy Weckwerth; Andreas Hense; Clemens Simmer

2008-10-01T23:59:59.000Z

448

Evaluation of Parametric Assumptions for Shallow Cumulus Convection  

Science Conference Proceedings (OSTI)

A large-eddy simulation (LES) model has been utilized to study nonprecipitating Shallow Convective clouds such as observed during the undisturbed BOMEX period in the trade wind areas. By choosing a realistic large-scale forcing the authors have ...

A. P. Siebesma; J. W. M. Cuijpers

1995-03-01T23:59:59.000Z

449

Fluctuations in an Equilibrium Convective Ensemble. Part I: Theoretical Formulation  

Science Conference Proceedings (OSTI)

To provide a theoretical basis for stochastic parameterization of cumulus convection, the equilibrium fluctuations of a field of cumulus clouds under homogeneous large-scale forcing are derived statistically, using the Gibbs canonical ensemble ...

George C. Craig; Brenda G. Cohen

2006-08-01T23:59:59.000Z

450

Equatorial Convectively Coupled Waves in a Simple Multicloud Model  

Science Conference Proceedings (OSTI)

Linear stability results for the multicloud model recently developed by the authors on an equatorial beta plane are presented here. The linearized equations, about a realistic radiative–convective equilibrium (RCE) are projected in the meridional ...

Boualem Khouider; Andrew J. Majda

2008-11-01T23:59:59.000Z

451

Lidar Observations of Banded Convection during BLX83  

Science Conference Proceedings (OSTI)

Lidar observations of clear-air convection during the 1983 Boundary Layer Experiment (BLX83) reveal the presence of elongated, parallel regions of updrafts marked by enhanced aerosol backscattering. These linear (banded) aerosol structures were ...

R. A. Ferrare; J. L. Schols; E. W. Eloranta; R. Coulter

1991-03-01T23:59:59.000Z

452

Spectral Characteristics of the Convective Boundary Layer Over Uneven Terrain  

Science Conference Proceedings (OSTI)

The paper describes a convective boundary layer experiment conducted in April 1978 at the Boulder Atmospheric Observatory, and examines the spectral behavior of wind velocity and temperature from the Observatory's 300 m tower, from aircraft ...

J. C. Kaimal; R. A. Eversole; D. H. Lenschow; B. B. Stankov; P. H. Kahn; J. A. Businger

1982-05-01T23:59:59.000Z

453

The AROME-France Convective-Scale Operational Model  

Science Conference Proceedings (OSTI)

After six years of scientific, technical developments and meteorological validation, the Application of Research to Operations at Mesoscale (AROME-France) convective-scale model became operational at Météo-France at the end of 2008. This paper ...

Y. Seity; P. Brousseau; S. Malardel; G. Hello; P. Bénard; F. Bouttier; C. Lac; V. Masson

2011-03-01T23:59:59.000Z

454

Observed Evolution of Tropical Deep Convective Events and Their Environment  

Science Conference Proceedings (OSTI)

Using a compositing technique, the temporal progression of tropical convective systems and the mean atmospheric state in their vicinity is constructed from a time series of geostationary satellite and operational rawinsonde data. The technique ...

Steven C. Sherwood; Ralph Wahrlich

1999-08-01T23:59:59.000Z

455

Convective Episodes in the East-Central United States  

Science Conference Proceedings (OSTI)

Nine years of composited radar data are investigated to assess the presence of organized convective episodes in the east-central United States. In the eastern United States, the afternoon maximum in thunderstorms is ubiquitous over land. However, ...

Matthew D. Parker; David A. Ahijevych

2007-11-01T23:59:59.000Z

456

Meso- and Submesoscale Structure of a Convecting Field  

Science Conference Proceedings (OSTI)

Intensive data collection in the region of the Labrador Sea northwest of former Ocean Weather Station Bravo during the winter of 1998 allowed examination of the meso- and submesoscale structure during active convection. Data used include ...

Elizabeth L. Steffen; Eric A. D'Asaro

2004-01-01T23:59:59.000Z

457

Circulations between Mesoscale Convective Systems along a Cold Front  

Science Conference Proceedings (OSTI)

A frontal squall line that passed over the central United States on 14–15 June 1985 consisted of several primary mesoscale convective systems (MCSs) with a prominent gap (several hundred kilometers wide) between two of them over central Kansas ...

Richard H. Johnson; Barbara D. Miner; Paul E. Ciesielski

1995-03-01T23:59:59.000Z

458

Deep Convective System Evolution over Africa and the Tropical Atlantic  

Science Conference Proceedings (OSTI)

In the tropical African and neighboring Atlantic region there is a strong contrast in the properties of deep convection between land and ocean. Here, satellite radar observations are used to produce a composite picture of the life cycle of ...

Joanna M. Futyan; Anthony D. Del Genio

2007-10-01T23:59:59.000Z

459

Synoptic Wave Perturbations and Convective Systems over Equatorial Africa  

Science Conference Proceedings (OSTI)

Spectral analysis of the outgoing longwave radiation (OLR) time series over equatorial Africa reveals large oscillations of the convection with periods of between 3 and 6 days. In March and April, when the intertropical convergence zone (ITCZ) ...

Hanh Nguyen; Jean-Philippe Duvel

2008-12-01T23:59:59.000Z

460

Synoptic Mapping of Convective Structure from Undersampled Satellite Observations  

Science Conference Proceedings (OSTI)

Climate properties regulated by convection, such as water vapor, cloud cover, and related distributions, are undersampled in asynoptic data from an individual orbiting platform, which must therefore be restricted to time-mean distributions. A ...

Murry Salby; Fabrizio Sassi

2001-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "measurement variable convection" 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

Sensitivity of Boundary-layer and Deep Convective Cloud Simulations...  

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

convective clouds using a cloud resolving model (CRM). A CRM usually uses a vertical grid spacing less than 100 m to simulate boundary layer clouds such as shallow cumuli and...

462

Transient Environmental Sensitivities of Explicitly Simulated Tropical Convection  

Science Conference Proceedings (OSTI)

A three-dimensional cloud-resolving model, maintained in a statistically steady convecting state by tropics-like forcing, is subjected to sudden (10 min) stimuli consisting of horizontally homogeneous temperature and/or moisture sources with ...

Stefan N. Tulich; Brian E. Mapes

2010-04-01T23:59:59.000Z

463

Gravity Waves and Convection in Colorado during July 1983  

Science Conference Proceedings (OSTI)

In order to gain insight into the complex dynamics of a convective system interacting with a gravity wave train, we have carried out an experiment in northeast Colorado during July and August, 1983, utilizing data from several program areas in ...

F. Einaudi; W. L. Clark; J. L. Green; T. E. VanZandt; D. Fua

1987-06-01T23:59:59.000Z

464

Structure of Large-Scale Convective Anomalies over Tropical Oceans  

Science Conference Proceedings (OSTI)

Geographical variations in the variance and cross-correlation of monthly mean sea surface temperature (SST), outgoing longwave radiation (OLR, a proxy for deep convection and vertical motion), and convergence of winds at the surface and at 850 mb ...

David S. Gutzler; Tamara M. Wood

1990-04-01T23:59:59.000Z

465

Overview of the Convection and Moisture Experiment (CAMEX)  

Science Conference Proceedings (OSTI)

This paper presents an overview of the Convection and Moisture Experiment (CAMEX), including the field operations, aircraft platforms and missions, instrumentation, and data acquired during 1998 and 2001 field campaigns. A total of eight tropical ...

Ramesh Kakar; Michael Goodman; Robbie Hood; Anthony Guillory

2006-01-01T23:59:59.000Z

466

Organizational Modes of Mesoscale Convective Systems over Central East China  

Science Conference Proceedings (OSTI)

Composite reflectivity Doppler radar data from June to September of 2007–2010 were used to classify mesoscale convective systems (MCSs) over central east China into seven morphologies. The morphologies included one nonlinear mode (NL) and six ...

Linlin Zheng; Jianhua Sun; Xiaoling Zhang; Changhai Liu

2013-10-01T23:59:59.000Z

467

Large-Eddy Simulation of the Convective Atmospheric Boundary Layer  

Science Conference Proceedings (OSTI)

Large-eddy simulations of a free convective atmospheric boundary layer with an overlying capping inversion are considered. Attention is given to the dependence of the results upon the various factors influencing the simulation: the subgrid model, ...

P. J. Mason

1989-06-01T23:59:59.000Z

468

Impact of Stochastic Physics in a Convection-Permitting Ensemble  

Science Conference Proceedings (OSTI)

A stochastic physics scheme is tested in the Application of Research to Operations at Mesoscale (AROME) short-range convection-permitting ensemble prediction system. It is an adaptation of ECMWF’s stochastic perturbation of physics tendencies (...

François Bouttier; Benoît Vié; Olivier Nuissier; Laure Raynaud

2012-11-01T23:59:59.000Z

469

Climatology of Tropical Intraseasonal Convective Anomalies: 1979–2002  

Science Conference Proceedings (OSTI)

Tropical intraseasonal convective anomalies (TICA) have a central role in subseasonal changes in the coupled ocean–atmosphere system, but the climatology of TICA events has not been properly documented. This study exploits 24 years of outgoing ...

Charles Jones; Leila M. V. Carvalho; R. Wayne Higgins; Duane E. Waliser; J-K. E. Schemm

2004-02-01T23:59:59.000Z

470

Circulation Anomalies Associated with Tropical Convection during Northern Winter  

Science Conference Proceedings (OSTI)

Lagged cross correlations between outgoing longwave radiation (OLR) and National Meteorological Center global analyses are utilized to isolate the preferred upper-level and surface circulation anomalies associated with tropical convection during ...

George N. Kiladis; Klaus M. Weickmann

1992-09-01T23:59:59.000Z

471

Reply to “Comments on ‘Preconditioning Deep Convection with Cumulus Congestus’”  

Science Conference Proceedings (OSTI)

In his comment, D. M. Schultz asked for clarification concerning (i) the validity of the results of C. Hohenegger and B. Stevens for the development of convection over the midlatitudes and (ii) the exact meaning and computation of the term “...

Cathy Hohenegger; Bjorn Stevens

2013-12-01T23:59:59.000Z

472

A Forced Gravity Wave Model of Serf-Organizing Convection  

Science Conference Proceedings (OSTI)

A two-dimensional, hydrostatic, nonrotating numerical model with a cumulus paramelerizafion is developed to study the early stages of mesozcale convective systems. Amplifying, forced gravity waves occur when peneirative downdrafts are present. ...

David J. Raymond

1987-12-01T23:59:59.000Z

473

Upscale Effects of Deep Convection during the North American Monsoon  

Science Conference Proceedings (OSTI)

The ability of deep monsoon convection to influence the larger-scale circulation over North America is investigated for a 6-day long case study during the 2006 North American monsoon season. Results from Rossby wave ray tracing and numerical ...

David J. Stensrud

474

The Role of Convective Instability in an Oklahoma Squall Line  

Science Conference Proceedings (OSTI)

Previous investigations of the 8 June 1966 National Severe Storms Laboratory case show that mesoscale lift from an “inland sea breeze” due to a newly formed temperature gradient preceded convection. Using additional surface data, this case was ...

Frank P. Colby Jr.

1980-09-01T23:59:59.000Z

475

Airborne Doppler Lidar Observations of Convective Phenomena in Oklahoma  

Science Conference Proceedings (OSTI)

On 30 June 1981, the wind fields around a variety of convective clouds, ranging from large thunderstorm complexes to isolated cumulus congestus, were observed in Oklahoma using an airborne Doppler lidar operated by the National Aeronautics and ...

Eugene W. McCaul Jr.; Howard B. Bluestein; Richard J. Doviak

1987-09-01T23:59:59.000Z

476

Comparing Model-produced Convective Cloudiness with Observations  

Science Conference Proceedings (OSTI)

Convective cloudiness generated by a cumulus parameterization scheme of a large-scale numerical weather prediction model was compared with analyses of clouds observed by geosynchronous satellites. The comparisons were performed over an equatorial ...

D. C. Norquist; C. Yang

1992-05-01T23:59:59.000Z

477

Midlevel Cyclonic Vortices Generated by Mesoseale Convective Systems  

Science Conference Proceedings (OSTI)

Despite the large number of convective systems that occur over the central United States every year, there are typically only a few well-defined, midlevel vortices apparent in satellite imagery after the overlying anvil debris from some ...

Diana L. Bartels; Robert A. Maddox

1991-01-01T23:59:59.000Z

478

Convectively Driven Mixing in the Bottom Boundary Layer  

Science Conference Proceedings (OSTI)

Closely spaced vertical profiles through the bottom boundary layer over a sloping continental shelf during relaxation from coastal upwelling reveal structure that is consistent with convectively driven mixing. Parcels of fluid were observed ...

J. N. Moum; A. Perlin; J. M. Klymak; M. D. Levine; T. Boyd; P. M. Kosro

2004-10-01T23:59:59.000Z

479

Atlantic Tropical Cyclogenesis: A Three-Way Interaction between an African Easterly Wave, Diurnally Varying Convection, and a Convectively Coupled Atmospheric Kelvin Wave  

Science Conference Proceedings (OSTI)

This paper explores a three-way interaction between an African easterly wave (AEW), the diurnal cycle of convection over the Guinea Highlands (GHs), and a convectively coupled atmospheric equatorial Kelvin wave (CCKW). These interactions resulted ...

Michael J. Ventrice; Christopher D. Thorncroft; Matthew A. Janiga

2012-04-01T23:59:59.000Z

480

Applicability of Large-Scale Convection and Condensation Parameterization to Meso-?-Scale HIRLAM: A Case Study of a Convective Event  

Science Conference Proceedings (OSTI)

This paper presents a case study of a single cold air outbreak event with widespread convective precipitation over southern Finland on 25 May 2001. The purpose of the study is to investigate the applicability of the convection and condensation ...

Sami Niemelä; Carl Fortelius

2005-08-01T23:59:59.000Z

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481

The Impact of Large-Scale Forcing on Skill of Simulated Convective Initiation and Upscale Evolution with Convection-Allowing Grid Spacings in the WRF  

Science Conference Proceedings (OSTI)

A set of mesoscale convective systems (MCSs) was simulated using the Weather Research and Forecasting model with 3-km grid spacing to investigate the skill at predicting convective initiation and upscale evolution into an MCS. Precipitation was ...

Jeffrey D. Duda; William A. Gallus Jr.

2013-08-01T23:59:59.000Z

482

An Analytical Study of the Dependence of Orientation and Propagation of the Arabian Sea Convection Bands on Wind Shear, Static Stability, and Preexisting Convection  

Science Conference Proceedings (OSTI)

Organization of convection into bands over the Arabian Sea during a monsoon onset was studied analytically. Observed vertical profiles of temperature, moisture, and wind velocity were used as base states by a linear model of convection to deduce ...

John R. Roadcap; Gandikota V. Rao

1993-06-01T23:59:59.000Z

483

A Numerical Sensitivity Study on the Impact of Soil Moisture on Convection-Related Parameters and Convective Precipitation over Complex Terrain  

Science Conference Proceedings (OSTI)

The impact of soil moisture on convection-related parameters and convective precipitation over complex terrain is studied by numerical experiments using the nonhydrostatic Consortium for Small-Scale Modeling (COSMO) model. For 1 day of the ...

Christian Barthlott; Norbert Kalthoff

2011-12-01T23:59:59.000Z

484

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

Science Conference Proceedings (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

485

Handbook of single-phase convective heat transfer  

Science Conference Proceedings (OSTI)

This book presents a comprehensive collection of convective heat transfer basics, methods of calculations, tables, charts and design parameters involving single-phase flows - the most commonly experienced mode in heat transfer problems. Topics covered include natural and forced convection under a wise variety of design conditions, such as ducts, crossflows, turbulent conditions, transitional states, curved and coiled ducts, over rods in metals and through bends, valves and fittings. The book provides sections on radiation interaction and fouling conditions.

Kakac, S.; Shah, R.K.; Aung, W.

1987-01-01T23:59:59.000Z

486

SCALE ANALYSIS OF CONVECTIVE MELTING WITH INTERNAL HEAT GENERATION  

SciTech Connect

Using a scale analysis approach, we model phase change (melting) for pure materials which generate internal heat for small Stefan numbers (approximately one). The analysis considers conduction in the solid phase and natural convection, driven by internal heat generation, in the liquid regime. The model is applied for a constant surface temperature boundary condition where the melting temperature is greater than the surface temperature in a cylindrical geometry. We show the time scales in which conduction and convection heat transfer dominate.

John Crepeau

2011-03-01T23:59:59.000Z

487

POSSIBLE SOLAR CYCLE VARIATIONS IN THE CONVECTION ZONE  

E-Print Network (OSTI)

Abstract. Using data from the Global Oscillations Network Group (GONG) that covers the period from 1995 to 1998 we study the change in frequencies of solar oscillations with solar activity. From these frequencies we attempt to determine any possible variation in solar structure with solar activity. We do not find any evidence of a change in the convection zone depth or extent of overshoot below the convection zone during the solar cycle.

Sarbani Basu; H. M. Antia

2008-01-01T23:59:59.000Z

488

Estimating Salinity Variance Dissipation Rate from Conductivity Microstructure Measurements  

Science Conference Proceedings (OSTI)

At the smallest length scales, conductivity measurements include a contribution from salinity fluctuations in the inertial–convective and viscous–diffusive ranges of the turbulent scalar variance spectrum. Interpreting these measurements is ...

Jonathan D. Nash; James N. Moum

1999-02-01T23:59:59.000Z

489

TURBULENT CONVECTION MODEL IN THE OVERSHOOTING REGION. II. THEORETICAL ANALYSIS  

SciTech Connect

Turbulent convection models (TCMs) are thought to be good tools to deal with the convective overshooting in the stellar interior. However, they are too complex to be applied to calculations of stellar structure and evolution. In order to understand the physical processes of the convective overshooting and to simplify the application of TCMs, a semi-analytic solution is necessary. We obtain the approximate solution and asymptotic solution of the TCM in the overshooting region, and find some important properties of the convective overshooting. (1) The overshooting region can be partitioned into three parts: a thin region just outside the convective boundary with high efficiency of turbulent heat transfer, a power-law dissipation region of turbulent kinetic energy in the middle, and a thermal dissipation area with rapidly decreasing turbulent kinetic energy. The decaying indices of the turbulent correlations k, u{sub r}'T'-bar, and T'T'-bar are only determined by the parameters of the TCM, and there is an equilibrium value of the anisotropic degree {omega}. (2) The overshooting length of the turbulent heat flux u{sub r}'T'-bar is about 1H{sub k} (H{sub k} = |dr/dln k|). (3) The value of the turbulent kinetic energy at the convective boundary k{sub C} can be estimated by a method called the maximum of diffusion. Turbulent correlations in the overshooting region can be estimated by using k{sub C} and exponentially decreasing functions with the decaying indices.

Zhang, Q. S.; Li, Y., E-mail: zqs@ynao.ac.cn, E-mail: ly@ynao.ac.cn [National Astronomical Observatories/Yunnan Observatory, Chinese Academy of Sciences, P.O. Box 110, Kunming 650011 (China)

2012-05-01T23:59:59.000Z

490

AN ANALYTIC RADIATIVE-CONVECTIVE MODEL FOR PLANETARY ATMOSPHERES  

Science Conference Proceedings (OSTI)

We present an analytic one-dimensional radiative-convective model of the thermal structure of planetary atmospheres. Our model assumes that thermal radiative transfer is gray and can be represented by the two-stream approximation. Model atmospheres are assumed to be in hydrostatic equilibrium, with a power-law scaling between the atmospheric pressure and the gray thermal optical depth. The convective portions of our models are taken to follow adiabats that account for condensation of volatiles through a scaling parameter to the dry adiabat. By combining these assumptions, we produce simple, analytic expressions that allow calculations of the atmospheric-pressure-temperature profile, as well as expressions for the profiles of thermal radiative flux and convective flux. We explore the general behaviors of our model. These investigations encompass (1) worlds where atmospheric attenuation of sunlight is weak, which we show tend to have relatively high radiative-convective boundaries; (2) worlds with some attenuation of sunlight throughout the atmosphere, which we show can produce either shallow or deep radiative-convective boundaries, depending on the strength of sunlight attenuation; and (3) strongly irradiated giant planets (including hot Jupiters), where we explore the conditions under which these worlds acquire detached convective regions in their mid-tropospheres. Finally, we validate our model and demonstrate its utility through comparisons to the average observed thermal structure of Venus, Jupiter, and Titan, and by comparing computed flux profiles to more complex models.

Robinson, Tyler D. [Astronomy Department, University of Washington, Box 351580, Seattle, WA 98195-1580 (United States); Catling, David C., E-mail: robinson@astro.washington.edu [Department of Earth and Space Sciences, University of Washington, Box 351310, Seattle, WA 98195-1310 (United States)

2012-09-20T23:59:59.000Z

491

Energy Analysis of Convectively Induced Wind Perturbations  

Science Conference Proceedings (OSTI)

Budgets of divergent and rotational components of kinetic energy (KD and KR) are examined for four upper level wind speed maxima that develop during the fourth Atmospheric Variability Experiment (AVE IV) and the first AVE-Severe Environmental ...

Henry E. Fuelberg; Dennis E. Buechler

1989-04-01T23:59:59.000Z

492

Total lightning observations of severe convection over North Texas  

E-Print Network (OSTI)

Five severe convective cells over North Texas from three separate dates were examined to determine what three dimensional, or “total” lightning data can add to the understanding of a convective cell’s intensity, propagation, and severe weather 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 and information regarding the intensity and kinematic properties of each cell. Total lightning products used by the National Weather Service Forecast Office in Fort Worth, Texas were compared to total lightning flash rate; a quantity that has been shown to be correlated to changes in cell intensity inferred from other sources, such as radar and satellite data. These products, specifically flash extent density (FED) were also compared to CG flash rate and radar derived measures from the WSR-88D sites. The results of this work show that FED and total flash rate are well correlated, with an average Pearson correlation value of 0.73, indicating that previous total flash rate results may also apply to FED. Lightning hooks, holes, and notches in FED displays indicated likely updraft regions, while appendages were observed to develop prior to deviant motion with two supercells. These results, combined with a greater update frequency provided a useful complement to radar data in the warning decision process. FED jumps were observed prior to several severe weather reports, indicating that total lightning activity may be related to updraft strength as found in past studies. However, FED jumps were sometimes observed without any associated severe event. More work is clearly needed to define what FED changes are of most importance in the short-term prediction of storm severity. The usefulness of the total lightning data on these dates was dependant upon LDAR network status and distance of the cell from the network center. The results of this study suggest that combining total flash rate trends with visual displays of FED provides the greatest added benefit to forecasters in maintaining situational awareness during warning operations.

McKinney, Christopher Michael

2008-08-01T23:59:59.000Z

493

Tropical Island Convection in the Absence of Significant Topography. Part I: Life Cycle of Diurnally Forced Convection  

Science Conference Proceedings (OSTI)

Diurnally forced convection was observed over the Tiwi Islands, north of the Australian continent, as part of the Maritime Continent Thunderstorm Experiment. Immature peninsula-scale (5–15 km) sea breezes were observed to initiate moist ...

R. E. Carbone; J. W. Wilson; T. D. Keenan; J. M. Hacker

2000-10-01T23:59:59.000Z

494

Comparing the Convective Structure and Microphysics in Two Sahelian Mesoscale Convective Systems: Radar Observations and CRM Simulations  

Science Conference Proceedings (OSTI)

Two mesoscale convective systems (MCSs) observed during the African Monsoon Multidisciplinary Analyses (AMMA) experiment are simulated using the three-dimensional (3D) Goddard Cumulus Ensemble model. This study was undertaken to determine the ...

Nick Guy; Xiping Zeng; Steven A. Rutledge; Wei-Kuo Tao

2013-02-01T23:59:59.000Z

495

Simulated Convective Lines with Parallel Stratiform Precipitation. Part I: An Archetype for Convection in Along-Line Shear  

Science Conference Proceedings (OSTI)

This article, the first of two describing convective lines with parallel stratiform (PS) precipitation, addresses the basic kinematic and precipitation features of these systems. The PS mode appears to be the preferred organizational structure in ...

Matthew D. Parker

2007-02-01T23:59:59.000Z

496

A Satellite-Based Convective Cloud Object Tracking and Multipurpose Data Fusion Tool with Application to Developing Convection  

Science Conference Proceedings (OSTI)

Studying deep convective clouds requires the use of available observation platforms with high temporal and spatial resolution, as well as other non–remote sensing meteorological data (i.e., numerical weather prediction model output, conventional ...

Justin M. Sieglaff; Daniel C. Hartung; Wayne F. Feltz; Lee M. Cronce; Valliappa Lakshmanan

2013-03-01T23:59:59.000Z

497

North Atlantic modeling of low-frequency variability in mode water formation  

E-Print Network (OSTI)

The generation of interannual and near-decadal variability in the formation of mode waters in the western North Atlantic is investigated in the realistic framework of an isopycnic coordinate ocean model forced with atmospheric data from 1946 to 1988. At Bermuda, the model reproduces quite well the observed potential vorticity and isopycnal depth anomalies associated with the subtropical mode water (STMW). Heat storage and preconditioning of the convective activity are found to be the important factors for the generation of STMW variability, with persistence of cold (warm) conditions, associated with anomalous heat loss (gain) over the western subtropics, being more significant for the generation of the simulated variability than are strong anomalous events in isolated years. In the Labrador Sea, the model captures the phase and order of magnitude of the observed near-decadal variability in the convective activity, if not its maximum amplitude. The simulated potential vorticity anomali...

Afonso M. Paiva; Eric P. Chassignet

2001-01-01T23:59:59.000Z

498

Field Measurement of Am241 and Total Uranium at a Mixed Oxide Fuel Facility with Variable Uranium Enrichments Ranging from 0.3% to 97% U235  

SciTech Connect

The uranium and transuranic content of site soils and building rubble can be accurately measured using a NaI(Tl) well counter, without significant soil preparation. Accurate measurements of total uranium in uranium-transuranic mixtures can be made, despite a wide range (0.3% to 97%) of uranium enrichment, sample mass, and activity concentrations. The appropriate uranium scaling factors needed to include the undetected uranium isotopes, particularly U 234 can be readily determined on a sample by sample basis as a part of the field analysis, by comparing the relative response of the U 235 186 keV peak versus the K shell X rays of U 238 , U 235, and their immediate ingrowth daughters. The ratio of the two results is a sensitive and accurate predictor of the uranium enrichment and scaling factors. The case study will illustrate how NaI(Tl) gamma spectrometry was used to provide rapid turnaround uranium and transuranic activity levels for soil and building rubble with sample by sample determination of the appropriate scaling factor to include the U234 and Uranium238 content.

Conway, K. C.

2002-02-28T23:59:59.000Z

499

U.S. Economic Sensitivity to Weather Variability  

Science Conference Proceedings (OSTI)

To estimate the economic effects of weather variability in the United States, the authors define and measure weather sensitivity as the variability in economic output that is attributable to weather variability, accounting for changes in technology and ...

Jeffrey K. Lazo; Megan Lawson; Peter H. Larsen; Donald M. Waldman

2011-06-01T23:59:59.000Z

500

Effects of cumulus convection on the simulated monsoon circulation in a general circulation model  

SciTech Connect

The effect of cumulus convection on the Asian summer monsoon circulation is investigated, using a general circulation model. Two simulations for the summer months (June, July, and August) are performed, one parameterizing convection using a mass flux scheme and the other without convective parameterization. The results show that convection has significant effects on the monsoon circulation and its associated precipitation. In the simulation with the mass flux convective parameterization, precipitation in the western Pacific is decreased, together with a decrease in surface evaporation and wind speed. In the indian monsoon region it is almost the opposite. Comparison with a simulation using moist convective adjustment to parameterize convection shows that the monsoon circulation and precipitation distribution in the no-convection simulation are very similar to those in the simulation with moist convective adjustment. The difference in the large-scale circulation with and without convective parameterization is interpreted in terms of convective stabilization of the atmosphere by convection, using dry and moist static energy budgets. It is shown that weakening of the low-level convergence in the western Pacific in the simulation with convection is closely associated with the stabilization of the atmosphere by convection, mostly through drying of the lower troposphere; changes in low-level convergence lead to changes in precipitation. The precipitation increase in the Indian monsoon can be explained similarly. 29 refs., 12 figs.

Zhang, Guang Jun (Univ. of California, San Diego, La Jolla, CA (United States))

1994-09-01T23:59:59.000Z