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Note: This page contains sample records for the topic "tropical ecosystem model" 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

Two Ecosystem Demography Models Released  

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

Ecosystem Demography Models Released Ecosystem Demography Models Released The ORNL DAAC is pleased to announce the release of two Ecosystem Demography Models: Ecosystem Demography Model: U.S. Ecosystem Carbon Stocks and Fluxes, 1700-1990 . Data set prepared by G. Hurtt, S.W. Pacala, P.R. Moorcroft, J. Caspersen, E. Shevliakova, R.A. Houghton, B. Moore III, and J. Fisk. This model product contains the source code for the Ecosystem Demography Model (ED version 1.0) as well as model input and output data files for the conterminous United States. The ED is a mechanistic ecosystem model built around established sub-models of leaf level physiology, organic matter decomposition, hydrology, and functional biodiversity. It was used herein to estimate ecosystem carbon stocks and fluxes in the conterminous U.S. at

2

Parallel Computing for Terrestrial Ecosystem Carbon Modeling  

Science Conference Proceedings (OSTI)

Terrestrial ecosystems are a primary component of research on global environmental change. Observational and modeling research on terrestrial ecosystems at the global scale, however, has lagged behind their counterparts for oceanic and atmospheric systems, largely because the unique challenges associated with the tremendous diversity and complexity of terrestrial ecosystems. There are 8 major types of terrestrial ecosystem: tropical rain forest, savannas, deserts, temperate grassland, deciduous forest, coniferous forest, tundra, and chaparral. The carbon cycle is an important mechanism in the coupling of terrestrial ecosystems with climate through biological fluxes of CO{sub 2}. The influence of terrestrial ecosystems on atmospheric CO{sub 2} can be modeled via several means at different timescales. Important processes include plant dynamics, change in land use, as well as ecosystem biogeography. Over the past several decades, many terrestrial ecosystem models (see the 'Model developments' section) have been developed to understand the interactions between terrestrial carbon storage and CO{sub 2} concentration in the atmosphere, as well as the consequences of these interactions. Early TECMs generally adapted simple box-flow exchange models, in which photosynthetic CO{sub 2} uptake and respiratory CO{sub 2} release are simulated in an empirical manner with a small number of vegetation and soil carbon pools. Demands on kinds and amount of information required from global TECMs have grown. Recently, along with the rapid development of parallel computing, spatially explicit TECMs with detailed process based representations of carbon dynamics become attractive, because those models can readily incorporate a variety of additional ecosystem processes (such as dispersal, establishment, growth, mortality etc.) and environmental factors (such as landscape position, pest populations, disturbances, resource manipulations, etc.), and provide information to frame policy options for climate change impact analysis.

Wang, Dali [ORNL; Post, Wilfred M [ORNL; Ricciuto, Daniel M [ORNL; Berry, Michael [University of Tennessee, Knoxville (UTK)

2011-01-01T23:59:59.000Z

3

ORNL DAAC, Biogeochemical Parameters for Ecosystem Modeling,...  

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

Parameters for Ecosystem Modeling The ORNL DAAC announces the release of a data set entitled "Literature-Derived Parameters for the BIOME-BGC Terrestrial Ecosystem...

4

Integrating Ecosystem Sampling, Gradient Modeling, Remote Sensing, and Ecosystem Simulation to Create Spatially Explicit Landscape Inventories  

E-Print Network (OSTI)

ecosystem sampling, gradient modeling, remote sensing, and ecosystem simulation to create spatially explicit landscape inventories. RMRS-GTR-92. Fort Collins, CO: U.S. Department

United States; Forest Service; Robert E. Keane; Matthew G. Rollins; Cecilia H. Mcnicoll; Russell A. Parsons Abstract

2002-01-01T23:59:59.000Z

5

Experiments with a Spectral Tropical Cyclone Model  

Science Conference Proceedings (OSTI)

The three-layer balanced axisymmetric tropical cyclone model presented by Ooyama is generalized to dimensions and the resultant primitive equations are solved using the spectral (Galerkin) method with Fourier basis functions on a doubly-periodic ...

Mark DeMaria; Wayne H. Schubert

1984-03-01T23:59:59.000Z

6

Statistical modelling of tropical cyclone tracks: modelling cyclone lysis  

E-Print Network (OSTI)

We describe results from the fifth stage of a project to build a statistical model of tropical cyclone tracks. The previous stages considered genesis and the shape of tracks. We now consider in more detail how to represent the lysis (death) of tropical cyclones. Improving the lysis model turns out to bring a significant improvement to the track model overall.

Hall, T; Hall, Tim; Jewson, Stephen

2005-01-01T23:59:59.000Z

7

Generalized Inversion of Tropical Atmosphere–Ocean Data and a Coupled Model of the Tropical Pacific  

Science Conference Proceedings (OSTI)

It is hypothesized that the circulation of the tropical Pacific Ocean and atmosphere satisfies the equations of a simple coupled model to within errors having specified covariances, and that the Tropical Atmosphere–Ocean array (TAO) measures the ...

Andrew F. Bennett; Boon S. Chua; D. Ed Harrison; Michael J. McPhaden

1998-07-01T23:59:59.000Z

8

A Model for Transport across the Tropical Tropopause  

Science Conference Proceedings (OSTI)

A model of convective and advective transport across the tropical tropopause is described. In this model overshooting convective turrets inject dehydrated tropospheric air into a tropical “tropopause layer” (TTL) bounded approximately by the 50- ...

Steven C. Sherwood; Andrew E. Dessler

2001-04-01T23:59:59.000Z

9

A Bayesian Forecast Model of Australian Region Tropical Cyclone Formation  

Science Conference Proceedings (OSTI)

A new and potentially skillful seasonal forecast model of tropical cyclone formation [tropical cyclogenesis (TCG)] is developed for the Australian region. The model is based on Poisson regression using the Bayesian approach. Predictor combinations ...

Angelika Werner; Neil J. Holbrook

2011-12-01T23:59:59.000Z

10

An Intermediate Model of the Tropical Pacific Ocean  

Science Conference Proceedings (OSTI)

An intermediate tropical Pacific Ocean model is developed to bridge the gap between anomaly models of El Niño and ocean general circulation models. The model contains essential physics for reproducing both the annual and interannual variations of ...

Bin Wang; Tianming Li; Ping Chang

1995-07-01T23:59:59.000Z

11

Development of a General Ecosystem Model for a Range of Scales and Ecosystems  

E-Print Network (OSTI)

We have developed a General Ecosystem Model (GEM) that is designed to simulate a variety of ecosystem types using a fixed model structure. Driven largely by hydrologic algorithms for upland, wetland and shallow-water habitats, the model captures the response of macrophyte and algal communities to simulated levels of nutrients, water, and environmental inputs. It explicitly incorporates ecological processes that determine water levels, plant production, nutrient cycling associated with organic matter decomposition, consumer dynamics, and fire. While the model may be used to simulate ecosystem dynamics for a single homogenous habitat, our primary objective is to replicate it as a "unit" model in heterogeneous, grid-based dynamic spatial models using different parameter sets for each habitat. Thus, we constrained the process (i.e., computational) complexity, yet targeted a level of disaggregation that would effectively capture the feedbacks among important ecosystem processes. A basic ver...

H. C. Fitz; E. B. DeBellevue; R. Costanza; R. Boumans; T. Maxwell; L. Wainger; F.H. Sklar

1994-01-01T23:59:59.000Z

12

Simulation of Tropical Climate with a Linear Primitive Equation Model  

Science Conference Proceedings (OSTI)

The tropical climate simulated with a new global atmosphere model is presented. The model is purposely designed for climate studies and is still under development. It is designed to bridge the gap between very efficient but simple models of the ...

Richard Seager; Stephen E. Zebiak

1995-10-01T23:59:59.000Z

13

Simulated Relationships between Sea Surface Temperatures and Tropical Convection in Climate Models and Their Implications for Tropical Cyclone Activity  

Science Conference Proceedings (OSTI)

The impact of enhanced atmospheric CO2 concentrations on tropical convection and sea surface temperatures (SSTs) over the global tropics is assessed using five fully coupled atmospheric–oceanic general circulation models (AOGCMs). Relationships ...

Jenni L. Evans; Jeffrey J. Waters

2012-11-01T23:59:59.000Z

14

Feedbacks in a Simple Prognostic Tropical Climate Model  

Science Conference Proceedings (OSTI)

A simple four-cell model of the tropical atmosphere in equilibrium with its boundaries is introduced, which can support a variable diabatic circulation and prognostic temperature and humidity profiles. The model is used to predict atmospheric ...

Steven C. Sherwood

1999-07-01T23:59:59.000Z

15

Vertical Velocity Structures in an Axisymmetric, Nonhydrostatic Tropical Cyclone Model  

Science Conference Proceedings (OSTI)

A statistical analysis of several experiments with different microphysical parameterizations in an axisymmetric, nonhydrostatic tropical cyclone model illustrates the impact of icc-phase microphysics on model vertical velocity structure. The ...

Stephen J. Lord; Jacqueline M. Lord

1988-05-01T23:59:59.000Z

16

An Error Analysis of Atlantic Tropical Cyclone Track Guidance Models  

Science Conference Proceedings (OSTI)

Mean track forecast errors over the 6-yr period 1983–88 are compared for four tropical cyclone-track forecast models in use at the National Hurricane Center (NHC). The model types represented are statistical, statistical-dynamical, barctropic-...

Mark Demaria; Miles B. Lawrence; James T. Kroll

1990-03-01T23:59:59.000Z

17

Initial Conditions for a General Circulation Model of Tropical Oceans  

Science Conference Proceedings (OSTI)

A general circulation model of the tropical Pacific Ocean, which realistically simulates El Niño of 1982–83, has been used to determine how different initial conditions affect the model. Given arbitrary initial conditions (not in equilibrium with ...

S. G. H. Philander; W. J. Hurlin; R. C. Pacanowski

1987-01-01T23:59:59.000Z

18

Linear Equatorial Wave Mode Initialization in a Model of the Tropical Pacific Ocean: An Initialization Scheme for Tropical Ocean Models  

Science Conference Proceedings (OSTI)

Data assimilation in models of the tropical oceans can generate spurious equatorial wave modes which are potentially harmful to the model background fields. The amplitudes of these spurious wave modes can often be large and, in general, depend ...

Andrew M. Moore

1990-03-01T23:59:59.000Z

19

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

20

Axisymmetric, Primitive Equation, Spectral Tropical Cyclone Model. Part I: Formulation  

Science Conference Proceedings (OSTI)

Beginning with the nine nonlinear governing equations for the simplest three-layer, axisymmetric, primitive equation, tropical cyclone model, we first introduce a vertical transform which decouples the linear part of the dynamics into three sets (...

Wayne H. Schubert; Mark DeMaria

1985-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical ecosystem model" 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

Modeling Tropical Convergence Based on the Moist Static Energy Budget  

Science Conference Proceedings (OSTI)

The vertically integrated moist static energy equation provides a convenient starting point for the construction of simple models of the time-mean low level convergence in the tropics. A vertically integrated measure of the moist static stability,...

J. David Neelin; Isaac M. Held

1987-01-01T23:59:59.000Z

22

Modeling Climate Variability in the Tropical Atlantic Atmosphere  

Science Conference Proceedings (OSTI)

Climate variability in the tropical Atlantic sector as represented in six atmospheric general circulation models is examined. On the annual mean, most simulations overestimate wind stress away from the equator although much of the variability can ...

Jiande Wang; James A. Carton

2003-12-01T23:59:59.000Z

23

An elastic contour matching model for tropical cyclone pattern recognition  

Science Conference Proceedings (OSTI)

In this paper, an elastic graph dynamic link model (EGDLM) based on elastic contour matching is proposed to automate the Dvorak technique for tropical cyclone (TC) pattern interpretation from satellite images. This method integrates traditional dynamic ...

R. S.T. Lee; J. N.K. Lin

2001-06-01T23:59:59.000Z

24

A New Parametric Tropical Cyclone Tangential Wind Profile Model  

Science Conference Proceedings (OSTI)

A new parametric tropical cyclone (TC) wind profile model is presented for depicting representative surface pressure profiles corresponding to multiple-maxima wind profiles that exhibit single-, dual-, and triple-maximum concentric-eyewall wind ...

Vincent T. Wood; Luther W. White; Hugh E. Willoughby; David P. Jorgensen

2013-06-01T23:59:59.000Z

25

An Adaptive Multigrid Barotropic Tropical Cyclone Track Model  

Science Conference Proceedings (OSTI)

This paper describes the application of adaptive multigrid techniques to the problem of tropical cyclone track prediction. Based on the nondivergent barotropic vorticity equation, the model uses an adaptive multigrid method to refine the mesh ...

Scott R. Fulton

2001-01-01T23:59:59.000Z

26

Improving the Detection and Tracking of Tropical Cyclones in Atmospheric General Circulation Models  

Science Conference Proceedings (OSTI)

Dynamical seasonal forecasts of tropical storm frequency require robust and efficient algorithms for detection and tracking of tropical storms in atmospheric general circulation models (AGCMs). Tropical storms are generally detected when dynamic ...

Suzana J. Camargo; Stephen E. Zebiak

2002-12-01T23:59:59.000Z

27

Virtual Field Campaigns on Deep Tropical Convection in Climate Models  

Science Conference Proceedings (OSTI)

High-resolution time–height data over warm tropical oceans are examined, from three global atmosphere models [GFDL’s Atmosphere Model 2 (AM2), NCAR’s Community Atmosphere Model, version 3 (CAM3), and a NASA Global Modeling and Assimilation Office ...

Brian Mapes; Julio Bacmeister; Marat Khairoutdinov; Cecile Hannay; Ming Zhao

2009-01-01T23:59:59.000Z

28

Interhemispheric teleconnections from tropical heat sources in intermediate and simple models  

Science Conference Proceedings (OSTI)

The mechanisms that control the interhemispheric teleconnections from tropical heat sources are investigated using an intermediate complexity model (a Quasi-Equilibrium Tropical Circulation Model, QTCM) and a simple linear two-level model with dry ...

X. Ji; J. D. Neelin; S.-K. Lee; C. R. Mechoso

29

A Modeling Study on the Early Electrical Development of Tropical Convection: Continental and Oceanic (Monsoon) Storms  

Science Conference Proceedings (OSTI)

Numerical modeling studies of continental tropical and maritime tropical convection were conducted using the two-dimensional, nonhydrostatic, cloud electrification model developed at the South Dakota School of Mines and Technology. The model ...

Scot C. Randell; Steven A. Rutledge; Richard D. Farley; John H. Helsdon Jr.

1994-08-01T23:59:59.000Z

30

A Model of Tropical Ocean-Atmosphere Interaction  

Science Conference Proceedings (OSTI)

A model is used to study ocean-atmosphere interaction in the tropics. The model ocean consists of the single baroclinic mode of a two-layer ocean. Thermodynamics in the upper layer is highly parameterized. If the interface is sufficiently shallow ...

Julian P. McCreary Jr.

1983-02-01T23:59:59.000Z

31

Scaling Up Economic Instruments for Biodiversity and Ecosystem Service Conservation in the Tropics  

E-Print Network (OSTI)

Global conservation organizations are mainly consumers of expertise in economics. In this essay, I discuss the capacity gaps in economic analysis that prevent all conservation organizations from being more successful. This problem has some urgency because concern for climate change impacts has generated support for increased public investments to conserve natural systems in the tropics not seen since the Brundtland report (World Commission on Environment and Development 1987). Specific landscape management investments are widely recognized to be an efficient response to climate change mitigation and adaptation goals. Economic instruments that incorporate the costs of environmental externalities into private landuse decisions also hold great promise in guiding expansion of biofuel production, and avoiding irreversible losses from new infrastructure and commodity production (Chomitz 2007). Unfortunately, although great strides have been made in the theoretical and practical use of economic instruments for achieving environmental outcomes in tropical landscapes, there are not enough sufficiently trained people to guide or monitor the implementation of these policy tools inside public, private, and NGO-sector institutions in key developing countries (Bonine 2003). There are many more organic farming certifiers than people who know why a forest

Biodiversity; Keith Alger

2008-01-01T23:59:59.000Z

32

Models of Tropical Cyclone Wind Distribution and Beta-Effect Propagation for Application to Tropical Cyclone Track Forecasting  

Science Conference Proceedings (OSTI)

A model of the tangential wind speed in the outer regions of tropical cyclones is proposed based on approximate conservation of angular momentum. The purpose is to derive an operationally useful model of the beta-effect propagation (BEP), which ...

Lester E. Carr III; Russell L. Elsberry

1997-12-01T23:59:59.000Z

33

The Impact of Horizontal Resolution on the Tropical Heat Budget in an Atlantic Ocean Model  

Science Conference Proceedings (OSTI)

An ocean general circulation model (OGCM) of the tropical Atlantic is coupled to an advective atmospheric boundary layer model. This configuration is used to investigate the hypothesis that resolving tropical instability waves (TIWs) in OGCMs ...

Markus Jochum; Raghu Murtugudde; Raffaele Ferrari; Paola Malanotte-Rizzoli

2005-03-01T23:59:59.000Z

34

Dynamic balances within tropical plumes in a global barotropic model  

E-Print Network (OSTI)

Tropical plumes are a common synoptic scale feature over the Eastern Pacific associated with subtropical jet and ITCZ intensifications. Because of data sparseness, operational analysis has yielded little information of the details of the tropical plume formation process. Tropical plumes have been simulated in a global 200 mb shallow water model with a realistic basic state (Blackwell 1990). Diagnostic budgets were calculated based on model output for absolute vorticity, divergence, and kinetic energy. Also, the movement of the zero absolute vorticity isopleth during plume formation is examined. This information is compared for cases with plume formation, without plume formation, and the basic state. Budget results indicate the convergent forcing center, when located near a strong absolute vorticity gradient, creates an equatorial Rossby wave source. This source generates a large scale, quasi-stationary equatorial Rossby wave which, if located near the ambient eastern Pacific trough, strengthens this trough into the tropics. As the trough strengthens, it displaces the vorticity gradient equatorward into the cmvergence forcing region. This vorticity gradient encroaches upon the forcing region and creates a second Rossby wave source. This generates a second, smaller scale Rossby wave which propagates to the northeast along the axis of strong vorticity gradient. This Rossby wave is highly divergent in nature, due to the model's small Rossby radius of deformation. The accompanying train of convergence/divergence centers distorts the potential trough to create significant cross contour flow, which accelerates the subtropical jet to the east of the trough, resulting in a tropical plume. This study indicates the Rossby wave and accompanying cross contour and ageostrophic flow adequately explain the formation of all three key tropical plume features.

Vest, Gerry Wilson

1993-01-01T23:59:59.000Z

35

A Test of Convective Parameterizations in a Tropical Cyclone Model  

Science Conference Proceedings (OSTI)

In recent years a number of different methods have been proposed for the inclusion of the effects of cumuli in numerical models of tropical cyclones. In this paper several of the Kuo-type parameterizations have been tested by simulating the ...

Jay S. Hobgood; John N. Rayner

1989-06-01T23:59:59.000Z

36

A Simple Model of the Wind-Driven Tropical Ocean  

Science Conference Proceedings (OSTI)

A simple analytic theory for some aspects of the wind-driven circulation in the tropical oceans is described. The nearly geostrophic subsurface currants and the pressure field are studied by means of a single-layer model. The flow is forced by ...

P. J. Phlips

1987-11-01T23:59:59.000Z

37

TDE Ecosystem Model Intercomparison Data Archive: Publications  

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

Aber, J.D., and C.A. Federer. 1992. A generalized, lumped-parameter model of photosynthesis, evapotranspiration, and net primary production in temperate and boreal forest...

38

Coupled Variability and Predictability in a Stochastic Climate Model of the Tropical Atlantic  

Science Conference Proceedings (OSTI)

The coupled variability and predictability of the tropical Atlantic ocean–atmosphere system were analyzed within the framework of a linear stochastic climate model. Despite the existence of a meridional dipole as the leading mode, tropical ...

Faming Wang; Ping Chang

2008-12-01T23:59:59.000Z

39

The Importance of Three Physical Processes in a Minimal Three-Dimensional Tropical Cyclone Model  

Science Conference Proceedings (OSTI)

The minimal three-dimensional tropical cyclone model developed by Zhu et al. is used to explore the role of shallow convection, precipitation-cooled downdrafts, and the vertical transport of momentum by deep convection on the dynamics of tropical ...

Hongyan Zhu; Roger K. Smith

2002-06-01T23:59:59.000Z

40

Prediction of Tropical Atlantic Sea Surface Temperatures Using Linear Inverse Modeling  

Science Conference Proceedings (OSTI)

The predictability of tropical Atlantic sea surface temperature on seasonal to interannual timescales by linear inverse modeling is quantified. The authors find that predictability of Caribbean Sea and north tropical Atlantic sea surface ...

Cécile Penland; Ludmila Matrosova

1998-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical ecosystem model" 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

Sensitivity of Tropical Cyclone Intensity to Ventilation in an Axisymmetric Model  

E-Print Network (OSTI)

The sensitivity of tropical cyclone intensity to ventilation of cooler, drier air into the inner core is examined using an axisymmetric tropical cyclone model with parameterized ventilation. Sufficiently strong ventilation ...

Tang, Brian

42

The Moist Static Energy Budget of a Composite Tropical Intraseasonal Oscillation in a Climate Model  

Science Conference Proceedings (OSTI)

The intraseasonal moist static energy (MSE) budget is analyzed in a climate model that produces realistic eastward-propagating tropical intraseasonal wind and precipitation variability. Consistent with the recharge–discharge paradigm for tropical ...

Eric D. Maloney

2009-02-01T23:59:59.000Z

43

Sensitivity of Tropical Cyclone Intensity to Ventilation in an Axisymmetric Model  

Science Conference Proceedings (OSTI)

The sensitivity of tropical cyclone intensity to ventilation of cooler, drier air into the inner core is examined using an axisymmetric tropical cyclone model with parameterized ventilation. Sufficiently strong ventilation induces cooling of the ...

Brian Tang; Kerry Emanuel

2012-08-01T23:59:59.000Z

44

Modeling the Impact of Land Surface Degradation on the Climate of Tropical North Africa  

Science Conference Proceedings (OSTI)

Degradation of the land surface has been suggested as a cause of persistent drought in tropical north Africa. A general circulation model is used to assess the impact of degradation of five regions within tropical north Africa. Idealized ...

Douglas B. Clark; Yongkang Xue; Richard J. Harding; Paul J. Valdes

2001-04-01T23:59:59.000Z

45

Modeling Tropical Precipitation in a Single Column  

Science Conference Proceedings (OSTI)

A modified formulation of the traditional single column model for representing a limited area near the equator is proposed. This formulation can also be considered a two-column model in the limit as the area represented by one of the columns ...

Adam H. Sobel; Christopher S. Bretherton

2000-12-01T23:59:59.000Z

46

Improving Ocean Model Initialization for Coupled Tropical Cyclone Forecast Models Using GODAE Nowcasts  

Science Conference Proceedings (OSTI)

To simulate tropical cyclone (TC) intensification, coupled ocean–atmosphere prediction models must realistically reproduce the magnitude and pattern of storm-forced sea surface temperature (SST) cooling. The potential for the ocean to support ...

G. R. Halliwell Jr.; L. K. Shay; S. D. Jacob; O. M. Smedstad; E. W. Uhlhorn

2008-07-01T23:59:59.000Z

47

Current Capability of Operational Numerical Models in Predicting Tropical Cyclone Intensity in the Western North Pacific  

Science Conference Proceedings (OSTI)

Forecasts of tropical cyclone (TC) intensity from six operational models (three global models and three regional models) during 2010 and 2011 are assessed to study the current capability of model guidance in the western North Pacific. The ...

Hui Yu; Peiyan Chen; Qingqing Li; Bi Tang

2013-04-01T23:59:59.000Z

48

Choosing a Boundary Layer Parameterization for Tropical Cyclone Modeling  

Science Conference Proceedings (OSTI)

The boundary layer in a tropical cyclone is in some respects unlike that elsewhere in the atmosphere. It is therefore necessary to evaluate boundary layer parameterizations for their suitability for use in tropical cyclone simulation. Previous ...

Jeffrey D. Kepert

2012-05-01T23:59:59.000Z

49

Improvements to the Operational Tropical Cyclone Wind Speed Probability Model  

Science Conference Proceedings (OSTI)

The National Hurricane Center Hurricane Probability Program, which estimated the probability of a tropical cyclone passing within a specific distance of a selected set of coastal stations, was replaced by the more general Tropical Cyclone Surface ...

Mark DeMaria; John A. Knaff; Michael J. Brennan; Daniel Brown; Richard D. Knabb; Robert T. DeMaria; Andrea Schumacher; Christopher A. Lauer; David P. Roberts; Charles R. Sampson; Pablo Santos; David Sharp; Katherine A. Winters

2013-06-01T23:59:59.000Z

50

The Maximum Intensity of Tropical Cyclones in Axisymmetric Numerical Model Simulations  

Science Conference Proceedings (OSTI)

An axisymmetric numerical model is used to evaluate the maximum possible intensity of tropical cyclones. As compared with traditionally formulated nonhydrostatic models, this new model has improved mass and energy conservation in saturated ...

George H. Bryan; Richard Rotunno

2009-06-01T23:59:59.000Z

51

An Evaluation of Tropical Cyclone Genesis Forecasts from Global Numerical Models  

Science Conference Proceedings (OSTI)

Tropical cyclone (TC) forecasts rely heavily on output from global numerical models. While considerable research has investigated the skill of various models with respect to track and intensity, few studies have considered how well global models ...

Daniel J. Halperin; Henry E. Fuelberg; Robert E. Hart; Joshua H. Cossuth; Philip Sura; Richard J. Pasch

2013-12-01T23:59:59.000Z

52

An evaluation of tropical cyclone genesis forecasts from global numerical models  

Science Conference Proceedings (OSTI)

Tropical cyclone (TC) forecasts rely heavily on output from global numerical models. While some research has investigated the skill of various models with respect to track and intensity, few studies have considered how well global models forecast ...

Daniel J. Halperin; Henry E. Fuelberg; Robert E. Hart; Joshua H. Cossuth; Philip Sura; Richard J. Pasch

53

TDE Ecosystem Model Intercomparison Data Archive: Model Descriptions  

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

Model Descriptions Model Descriptions BGC++ BIOME-BGC CANOAK EALCO ecosys INTRASTAND LaRS LINKAGES v2.1 LoTEC MAESTRA NuCM PnET II SPA Literature Cited A total of 13 models were used in this study covering a range of temporal scales, spatial complexity, and mechanistic detail (Figure 1). Eight of the models (8) used an hourly time step, four models used a daily time step, and only one model used a monthly time step (i.e., PnET-II). Most models provided estimates for both stand carbon and water budgets, but other were limited to either the carbon (MAESTRA) or water (LINKAGES and NuCM) budgets. The most mechanistically complex models (ecosys, CLASS, LaRS, and CANOAK) also used a complete energy balance. A brief description of each of the models is provided below. BGC++ The BGC++ model (Hunt et al. 1999) simulates carbon, nitrogen, and

54

Tropical Atlantic Decadal Oscillation and Its Potential Impact on the Equatorial Atmosphere–Ocean Dynamics: A Simple Model Study  

Science Conference Proceedings (OSTI)

Simple coupled atmosphere–ocean models are used to study the potential influence of the tropical Atlantic Ocean decadal oscillation on the equatorial Atlantic atmosphere–ocean dynamics. Perturbing the model tropical Atlantic at the extratropics (...

Sang-Ki Lee; Chunzai Wang

2008-01-01T23:59:59.000Z

55

A Comparison of the Performance of Two Operational Dynamic Tropical Cyclone Models  

Science Conference Proceedings (OSTI)

This paper compares the performance of two multi-level high-resolution baroclinic tropical cyclone models which are currently in operational use. In the Atlantic, the National Hurricane Center utilizes the Movable Fine-mesh Model (MFM) for ...

Michael Fiorino; Edward J. Harrison Jr.; Donald G. Marks

1982-07-01T23:59:59.000Z

56

Stochastic behavior of tropical convection in observations and a multicloud model  

Science Conference Proceedings (OSTI)

The aim for a more accurate representation of tropical convection in global circulation models is a long-standing issue. Here, the relationships between large- and convective scales in observations and a Stochastic Multicloud Model (SMCM) to ...

Karsten Peters; Christian Jakob; Laura Davies; Boualem Khouider; Andrew J. Majda

57

Tropical Cyclone-like Vortices in a Limited Area Model: Comparison with Observed Climatology  

Science Conference Proceedings (OSTI)

A climate simulation of a limited area model implemented over the Australian region is analyzed for the presence of low pressure systems that have some of the physical characteristics of tropical cyclones. The model is run at a horizontal ...

Kevin Walsh; Ian G. Watterson

1997-09-01T23:59:59.000Z

58

Microwave Simulations of a Tropical Rainfall System with a Three-Dimensional Cloud Model  

Science Conference Proceedings (OSTI)

A three-dimensional cloud model-microwave radiative transfer model combination is used to study the relations among the precipitation and other microphysical characteristics of a tropical oceanic squall line and the upwelling radiance at ...

Robert F. Adler; Hwa-Young M. Yeh; N. Prasad; Wei-Kuo Tao; Joanne Simpson

1991-07-01T23:59:59.000Z

59

Initial Results From The Navy Two-Way Interactive Nested Tropical Cyclone Model  

Science Conference Proceedings (OSTI)

A primitive equation, two-way interactive nested tropical cyclone model has been developed by the Naval Environmental Prediction Research Facility for operational use during the 1980 typhoon season. The fine mesh grid of the model operates ...

Edward J. Harrison Jr.

1981-01-01T23:59:59.000Z

60

Freshwater Flux (FWF)-Induced Oceanic Feedback in a Hybrid Coupled Model of the Tropical Pacific  

Science Conference Proceedings (OSTI)

The impacts of freshwater flux (FWF) forcing on interannual variability in the tropical Pacific climate system are investigated using a hybrid coupled model (HCM), constructed from an oceanic general circulation model (OGCM) and a simplified ...

Rong-Hua Zhang; Antonio J. Busalacchi

2009-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical ecosystem model" 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

A Simple Empirical Model for Predicting the Decay of Tropical Cyclone Winds after Landfall  

Science Conference Proceedings (OSTI)

An empirical model for predicting the maximum wind of landfalling tropical cyclones is developed. The model is based upon the observation that the wind speed decay rate after landfall is proportional to the wind speed. Observations also indicate ...

John Kaplan; Mark DeMaria

1995-11-01T23:59:59.000Z

62

Melting of Snow Cover in a Tropical Mountain Environment in Bolivia: Processes and Modeling  

Science Conference Proceedings (OSTI)

To determine the physical processes involved in the melting and disappearance of transient snow cover in nonglacierized tropical areas, the CROCUS snow model, interactions between Soil–Biosphere–Atmosphere (ISBA) land surface model, and coupled ...

Yves Lejeune; Ludovic Bouilloud; Pierre Etchevers; Patrick Wagnon; Pierre Chevallier; Jean-Emmanuel Sicart; Eric Martin; Florence Habets

2007-08-01T23:59:59.000Z

63

North American tropical cyclone landfall and SST: a statistical model study  

Science Conference Proceedings (OSTI)

A statistical-stochastic model of the complete lifecycle of North Atlantic (NA) tropical cyclones (TCs) is used to examine the relationship between climate and landfall rates along the North-American Atlantic and Gulf coasts. The model draws on ...

Timothy Hall; Emmi Yonekura

64

A Minimal Model for the Short-Term Prediction of Rainfall in the Tropics  

Science Conference Proceedings (OSTI)

A “minimal” model is proposed here for the short-term prediction (up to 12 h ahead) of precipitation occurrence in the tropics. The model is purely statistical, consisting of an optimally weighted linear combination of a Markov chain and ...

K. Fraedrich; L. M. Leslie

1988-09-01T23:59:59.000Z

65

The Tropical Water and Energy Cycles in a Cumulus Ensemble Model. Part I: Equilibrium Climate  

Science Conference Proceedings (OSTI)

A cumulus ensemble model is used to study the tropical water and energy cycles and their role in the climate system. The model includes cloud dynamics, radiative processes, and microphysics that incorporate all important production and conversion ...

C. H. Sui; K. M. Lau; W. K. Tao; J. Simpson

1994-03-01T23:59:59.000Z

66

Simulation of the Tropical Pacific Warm Pool with the NCAR Climate System Model  

Science Conference Proceedings (OSTI)

The simulation of the tropical western Pacific warm pool is explored with the NCAR Climate System Model (CSM). The simulated sea surface temperatures in the Pacific basin have biases that are similar to other coupled model simulations in this ...

J. T. Kiehl

1998-06-01T23:59:59.000Z

67

Reproducibility by Climate Models of Cloud Radiative Forcing Associated with Tropical Convection  

Science Conference Proceedings (OSTI)

In this study, cloud radiative forcing (CRF) associated with convective activity over tropical oceans is analyzed for monthly mean data from twentieth-century simulations of 18 climate models participating in phase 3 of the Coupled Model ...

Hiroki Ichikawa; Hirohiko Masunaga; Yoko Tsushima; Hiroshi Kanzawa

2012-02-01T23:59:59.000Z

68

Properties of Tropical Cloud Ensembles Estimated Using a Cloud Model and an Observed Updraft Population  

Science Conference Proceedings (OSTI)

A simple cloud model is developed which is designed for both diagnostic studies and mesoscale cumulus parameterization experiments. The cloud model is combined with an observed population of tropical convective updrafts and used to examine the ...

William M. Frank; Charles Cohen

1985-09-01T23:59:59.000Z

69

Tropical Water Vapor and Cloud Feedbacks in Climate Models: A Further Assessment Using Coupled Simulations  

Science Conference Proceedings (OSTI)

By comparing the response of clouds and water vapor to ENSO forcing in nature with that in Atmospheric Model Intercomparison Project (AMIP) simulations by some leading climate models, an earlier evaluation of tropical cloud and water vapor ...

De-Zheng Sun; Yongqiang Yu; Tao Zhang

2009-03-01T23:59:59.000Z

70

Performance of the Nested Tropical Cyclone Model as a Function of Five Storm-Related Parameters  

Science Conference Proceedings (OSTI)

A detailed analysis of the performance of the U.S. Navy Nested Tropical Cyclone Model (NTCM) for western North Pacific tropical cyclones is made based on five storm-related factors: latitude, longitude, intensity, 12-h intensity change and size (...

Johnny C-L. Chan; Brian J. Williams; Russell L. Elsberry

1987-07-01T23:59:59.000Z

71

A Note on the Sea Surface Temperature Sensitivity of a Numerical Model of Tropical Storm Genesis  

Science Conference Proceedings (OSTI)

In a three-dimensional numerical model of a tropical disturbance, a spectrum of development stages, from a weakening wave to a mature tropical storm, was obtained with a 5 K range (298 to 303 K) sea surface temperature (SST). However, the ...

Robert E. Tuleya; Yoshio Kurihara

1982-12-01T23:59:59.000Z

72

A framework for modeling payments for ecosystem services with agent-based models, Bayesian belief networks and opinion dynamics models  

Science Conference Proceedings (OSTI)

We present an integrated modeling framework for simulating land-use decision making under the influence of payments for ecosystem services. The model combines agent-based modeling (ABM) with Bayesian belief networks (BBNs) and opinion dynamics models ... Keywords: Agent based modeling, Bayesian network, China, Human-environment interaction, IAMO-LUC, Land use change, Payments for environmental services, Social influence

Zhanli Sun, Daniel MüLler

2013-07-01T23:59:59.000Z

73

Local Coupled Equatorial Variability versus Remote ENSO Forcing in an Intermediate Coupled Model of the Tropical Atlantic  

Science Conference Proceedings (OSTI)

The relative roles played by the remote El Niño–Southern Oscillation (ENSO) forcing and the local air–sea interactions in the tropical Atlantic are investigated using an intermediate coupled model (ICM) of the tropical Atlantic. The oceanic ...

Serena Illig; Boris Dewitte

2006-10-01T23:59:59.000Z

74

Sensitivity of Tropical Cyclones to Surface Exchange Coefficients and a Revised Steady-State Model incorporating Eye Dynamics  

Science Conference Proceedings (OSTI)

Numerical and theoretical models of tropical cyclones indicate that the maximum wind speed in mature storms is sensitive to the ratio of the enthalpy and momentum surface exchange coefficients and that the spinup time of tropical cyclones varies ...

Kerry A. Emanuel

1995-11-01T23:59:59.000Z

75

Tropical Oceanic Response to Extratropical Thermal Forcing in a Coupled Climate Model: A Comparison between the Atlantic and Pacific Oceans  

Science Conference Proceedings (OSTI)

The tropical oceanic response to the extratropical thermal forcing is quantitatively estimated in a coupled climate model. This work focuses on comparison of the responses between the tropical Atlantic and Pacific. Under the same extratropical ...

Haijun Yang; Lu Wang

2011-08-01T23:59:59.000Z

76

Customization of RegCM3 Regional Climate Model for Eastern Africa and a Tropical Indian Ocean Domain  

Science Conference Proceedings (OSTI)

Rainfall is a driving factor of climate in the tropics and needs to be properly represented within a climate model. This study customizes the precipitation processes over the tropical regions of eastern Africa and the Indian Ocean using the ...

Neil Davis; Jared Bowden; Fredrick Semazzi; Lian Xie; Bari? Önol

2009-07-01T23:59:59.000Z

77

Comparison of explicitly simulated and downscaled tropical cyclone activity in a high-resolution global climate model  

E-Print Network (OSTI)

The response of tropical cyclone activity to climate change is a matter of great inherent interest and practical importance. Most current global climate models are not, however, capable of adequately resolving tropical ...

Emanuel, Kerry Andrew

78

Variational Data Assimilation for Determining the Seasonal Net Surface Heat Flux Using a Tropical Pacific Ocean Model  

Science Conference Proceedings (OSTI)

The authors present a study for determining the seasonal net surface heat flux over the tropical Pacific Ocean using an adjoint technique. A simple tropical ocean model with thermodynamics is chosen and the seasonal sea surface temperature (SST) ...

Lisan Yu; James J. O'Brien

1995-10-01T23:59:59.000Z

79

Modeling net ecosystem metabolism with an artificial neural network and Bayesian belief network  

Science Conference Proceedings (OSTI)

Artificial neural networks (ANNs) and Bayesian belief networks (BBNs) utilizing select environmental variables were developed and evaluated, with the intent to model net ecosystem metabolism (a proxy for system trophic state) within a freshwater wetland. ... Keywords: Artificial neural networks, Bayesian belief networks, Knowledge extraction, Net ecosystem metabolism

William A. Young, II; David F. Millie; Gary R. Weckman; Jerone S. Anderson; David M. Klarer; Gary L. Fahnenstiel

2011-10-01T23:59:59.000Z

80

An Extended Model for the Potential Intensity of Tropical Cyclones  

Science Conference Proceedings (OSTI)

Emanuel’s theory of hurricane potential intensity (E-PI) makes use of the assumption that slantwise convective instability vanishes in a steady-state vortex of a tropical cyclone. In the framework of an extended mathematical potential intensity ...

Thomas Frisius; Daria Schönemann

2012-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical ecosystem model" 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

A Comprehensive Test of the Navy Nested Tropical Cyclone Model  

Science Conference Proceedings (OSTI)

The tropical cyclone forecasting skill level of the Joint Typhoon Warning Center (JTWC) has reached a plateau and has shown little or no lasting improvement during the last 10 years. Because JTWC relies on an array of statistical and ...

Edward J. Harrison Jr.; Michael Fiorino

1982-07-01T23:59:59.000Z

82

Tropical Intraseasonal Oscillations Appearing in a GFDL General Circulation Model and FGGE Data. Part II: Structure  

Science Conference Proceedings (OSTI)

Space-time spectral and filter analyses are made of the structure of the tropical intraseasonal oscillations appearing in a GFDL 30-wavenumber spectral general circulation model and the FGGE IIIb data set.

Y. Hayashi; D. G. Golder

1988-11-01T23:59:59.000Z

83

ARM - PI Product - A Model Evaluation Data Set for the Tropical...  

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

ProductsA Model Evaluation Data Set for the Tropical ARM Sites Comments? We would love to hear from you Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : A...

84

The Development and Assessment of a Model-, Grid-, and Basin-Independent Tropical Cyclone Detection Scheme  

Science Conference Proceedings (OSTI)

A novel approach to tropical cyclone (TC) detection in coarse-resolution numerical model data is introduced and assessed. This approach differs from traditional detectors in two main ways. First, it was developed and tuned using 20 yr of ECMWF ...

K. J. Tory; S. S. Chand; R. A. Dare; J. L. McBride

2013-08-01T23:59:59.000Z

85

A Simple Model of Climatological Rainfall and Vertical Motion Patterns over the Tropical Oceans  

E-Print Network (OSTI)

A simple model is developed that predicts climatological rainfall, vertical motion, and diabatic heating profiles over the tropical oceans given the sea surface temperature (SST), using statistical relationships deduced ...

Back, Larissa E.

86

Variational Data Assimilation in the Tropics Using Precipitation Data. Part II: 3D Model  

Science Conference Proceedings (OSTI)

A global primitive equation model is used to examine the performance of four-dimensional variational data assimilation (4D-VAR) with moist processes and to assess the impact of assimilating precipitation data in the Tropics. Several types of ...

Tadashi Tsuyuki

1996-11-01T23:59:59.000Z

87

A Simple Model of Climatological Rainfall and Vertical Motion Patterns over the Tropical Oceans  

Science Conference Proceedings (OSTI)

A simple model is developed that predicts climatological rainfall, vertical motion, and diabatic heating profiles over the tropical oceans given the sea surface temperature (SST), using statistical relationships deduced from the 40-yr ECMWF Re-...

Larissa E. Back; Christopher S. Bretherton

2009-12-01T23:59:59.000Z

88

Influence of model biases on projected future changes in tropical cyclone frequency of occurrence  

Science Conference Proceedings (OSTI)

The influence of model biases on projected future changes in the frequency of occurrence of tropical cyclones (FOCs) was investigated using a new empirical statistical method. Assessments were made of present-day (1979–2003) simulations and future ...

Hiroyuki Murakami; Pang-Chi Hsu; Osamu Arakawa; Tim Li

89

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

Science Conference Proceedings (OSTI)

By applying a cloud tracking algorithm to tropical convective systems in a simulated a regional high resolution model simulation, this study documents the environmental conditions before and after convective systems are initiated over ocean and ...

Samson Hagos; Zhe Feng; Sally McFarlane; L. Ruby Leung

90

Tropical Cyclone Prediction Using a Barotropic Model Initialized by a Generalized Inverse Method  

Science Conference Proceedings (OSTI)

A nested, nondivergent barotropic numerical weather prediction model for forecasting tropical cyclone motion out to 48 h is initialized at time t = 0 by assimilating data from the preceding 24 h. The assimilation scheme finds the generalized ...

A. F. Bennett; L. M. Leslie; C. R. Hagelberg; P. E. Powers

1993-06-01T23:59:59.000Z

91

Assimilation of Temperature Profiles in a General Circulation Model of the Tropical Atlantic  

Science Conference Proceedings (OSTI)

Thirty-six hundred temperature profiles collected during 1984 were assimilated into a multilayer primitive equation model of the tropical Atlantic Ocean. The method consists in a monthly correction of the simulated temperature field. Each month, ...

Alain Morliére; Gills Reverdin; Jacques Merle

1989-12-01T23:59:59.000Z

92

Comparing tropical precipitation simulated by the Met Office NWP and climate models with satellite observations  

Science Conference Proceedings (OSTI)

Forecasts of precipitation and water vapor made by the UK Met Office global Numerical Weather Prediction (NWP) model are evaluated using products from satellite observations of Special Sensor Microwave Imager/Sounder (SSMIS) and Tropical Rainfall ...

Chunlei Liu; Richard P. Allan; Malcolm Brooks; Sean Milton

93

A Regional Ocean–Atmosphere Model for Eastern Pacific Climate: Toward Reducing Tropical Biases  

Science Conference Proceedings (OSTI)

The tropical Pacific Ocean is a climatically important region, home to El Niño and the Southern Oscillation. The simulation of its climate remains a challenge for global coupled ocean–atmosphere models, which suffer large biases especially in ...

Shang-Ping Xie; Toru Miyama; Yuqing Wang; Haiming Xu; Simon P. de Szoeke; R. Justin O. Small; Kelvin J. Richards; Takashi Mochizuki; Toshiyuki Awaji

2007-04-01T23:59:59.000Z

94

Mixed Layer Modeling of Intraseasonal Variability in the Tropical Western Pacific and Indian Oceans  

Science Conference Proceedings (OSTI)

Sea surface temperature (SST) variations associated with the atmospheric intraseasonal oscillation in the tropical Indian and western Pacific Oceans, are examined using a one-dimensional mixed layer model. Surface fluxes associated with 10 well-...

Toshiaki Shinoda; Harry H. Hendon

1998-10-01T23:59:59.000Z

95

Investigating Global Tropical Cyclone Activity with a Hierarchy of AGCMs: The Role of Model Resolution  

Science Conference Proceedings (OSTI)

The ability to run general circulation models (GCMs) at ever-higher horizontal resolutions has meant that tropical cyclone simulations are increasingly credible. A hierarchy of atmosphere-only GCMs, based on the Hadley Centre Global Environmental ...

Jane Strachan; Pier Luigi Vidale; Kevin Hodges; Malcolm Roberts; Marie-Estelle Demory

2013-01-01T23:59:59.000Z

96

Performance of the United Kingdom Meteorological Office Global Model in Predicting the Movement of Tropical Cyclones  

Science Conference Proceedings (OSTI)

A detailed evaluation of the performance of the United Kingdom Meteorological Office Global Model (UKMO) in predicting the movement of 15 tropical cyclones (TCs) that occurred over the western North Pacific during 1987 is presented. The ...

Johnny C. L. Chan; Wai-Kau Kay

1993-09-01T23:59:59.000Z

97

A Test of the ECMWF Model in Tropical Synoptic-Scale Diagnosis  

Science Conference Proceedings (OSTI)

The originally disseminated ECMWF-FGGE analyses for January and February 1979 are used to study the model performance in the deep tropics. Vertical velocities representing both the normal-mode initialized and uninitialized synoptic-scale flow are ...

Ray-qing Lin; Donald R. Mock

1986-08-01T23:59:59.000Z

98

A Test of the Simulation of Tropical Convective Cloudiness by a Cloud-Resolving Model  

Science Conference Proceedings (OSTI)

A methodology is described for testing the simulation of tropical convective clouds by models through comparison with observations of clouds and precipitation from earth-orbiting satellites. Clouds are divided into categories that represent ...

Mario A. Lopez; Dennis L. Hartmann; Peter N. Blossey; Robert Wood; Christopher S. Bretherton; Terence L. Kubar

2009-06-01T23:59:59.000Z

99

A Model Investigation of Aerosol-Induced Changes in Tropical Circulation  

Science Conference Proceedings (OSTI)

This study investigates how anthropogenic aerosols, alone or in conjunction with radiatively active gases, affect the tropical circulation with an atmosphere/mixed layer–ocean general circulation model. Aerosol-induced cooling gives rise to a ...

Yi Ming; V. Ramaswamy

2011-10-01T23:59:59.000Z

100

A Quasi-Equilibrium Tropical Circulation Model—Implementation and Simulation  

Science Conference Proceedings (OSTI)

The quasi-equilibrium tropical circulation model (QTCM1) is implemented and tested. The formulation, described by Neelin and Zeng, uses a Galerkin framework in the vertical, but with basis functions tailored to quasi-equilibrium deep convective ...

Ning Zeng; J. David Neelin; Chia Chou

2000-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical ecosystem model" 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

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

102

Modeling Seasonal Tropical Cyclone Activity in the Fiji Region as a Binary Classification Problem  

Science Conference Proceedings (OSTI)

This study presents a binary classification model for the prediction of tropical cyclone (TC) activity in the Fiji, Samoa, and Tonga regions (the FST region) using the accumulated cyclone energy (ACE) as a proxy of TC activity. A probit regression ...

Savin S. Chand; Kevin J. E. Walsh

2012-07-01T23:59:59.000Z

103

Analysis of Tropical–Extratropical Interactions with Influence Functions of a Barotropic Model  

Science Conference Proceedings (OSTI)

Influence functions (IFs) of a linear barotropic vorticity equation model are computed in order to determine the regions in which anomalous divergence at upper levels, related to tropical heating anomalies, has the largest impact on certain ...

Alice M. Grimm; Pedro L. Silva Dias

1995-10-01T23:59:59.000Z

104

The Impact of Tropical Forcing on Extratropical Predictability in a Simple Global Model  

Science Conference Proceedings (OSTI)

The impact of tropical forcing on the predictability of the extratropical atmosphere is studied. Using a two-layer spectral model, numerical experiments and diagnostic analyses have been carried out to examine the enhancement of predictability ...

Jianchun Qin; Walter A. Robinson

1995-11-01T23:59:59.000Z

105

A Two-Box Model of a Zonal Atmospheric Circulation in the Tropics  

Science Conference Proceedings (OSTI)

A simple fixed-SST model of a zonal circulation in the tropical atmosphere has been developed that has separate boxes for the ascending and descending branches of the atmospheric circulation. This circulation resembles the Walker circulation. ...

Michael A. Kelly; David A. Randall

2001-10-01T23:59:59.000Z

106

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

Science Conference Proceedings (OSTI)

By applying a cloud-tracking algorithm to tropical convective systems in a regional high-resolution model simulation, this study documents the environmental conditions before and after convective systems are initiated over ocean and land by ...

Samson Hagos; Zhe Feng; Sally McFarlane; L. Ruby Leung

2013-08-01T23:59:59.000Z

107

Tropical Cooling at the Last Glacial Maximum: An Atmosphere–Mixed Layer Ocean Model Simulation  

Science Conference Proceedings (OSTI)

The sensitivity of tropical temperature to glacial forcing is examined by using an atmosphere–mixed layer ocean (A–MLO) model to simulate the climate of the last glacial maximum (LGM) following specifications established by the Paleoclimate ...

Anthony J. Broccoli

2000-03-01T23:59:59.000Z

108

A hierarchical analysis of terrestrial ecosystem model Biome-BGC: Equilibrium analysis and model calibration  

Science Conference Proceedings (OSTI)

The increasing complexity of ecosystem models represents a major difficulty in tuning model parameters and analyzing simulated results. To address this problem, this study develops a hierarchical scheme that simplifies the Biome-BGC model into three functionally cascaded tiers and analyzes them sequentially. The first-tier model focuses on leaf-level ecophysiological processes; it simulates evapotranspiration and photosynthesis with prescribed leaf area index (LAI). The restriction on LAI is then lifted in the following two model tiers, which analyze how carbon and nitrogen is cycled at the whole-plant level (the second tier) and in all litter/soil pools (the third tier) to dynamically support the prescribed canopy. In particular, this study analyzes the steady state of these two model tiers by a set of equilibrium equations that are derived from Biome-BGC algorithms and are based on the principle of mass balance. Instead of spinning-up the model for thousands of climate years, these equations are able to estimate carbon/nitrogen stocks and fluxes of the target (steady-state) ecosystem directly from the results obtained by the first-tier model. The model hierarchy is examined with model experiments at four AmeriFlux sites. The results indicate that the proposed scheme can effectively calibrate Biome-BGC to simulate observed fluxes of evapotranspiration and photosynthesis; and the carbon/nitrogen stocks estimated by the equilibrium analysis approach are highly consistent with the results of model simulations. Therefore, the scheme developed in this study may serve as a practical guide to calibrate/analyze Biome-BGC; it also provides an efficient way to solve the problem of model spin-up, especially for applications over large regions. The same methodology may help analyze other similar ecosystem models as well.

Thornton, Peter E [ORNL; Wang, Weile [ORNL; Law, Beverly E. [Oregon State University; Nemani, Ramakrishna R [NASA Ames Research Center

2009-01-01T23:59:59.000Z

109

Mathematical Modelling and Numerical Simulation of Marine Ecosystems With Applications to Ice Algae.  

E-Print Network (OSTI)

??Sea-ice ecosystem modelling is a novel field of research. In this thesis, the main organism studied is sea-ice algae. A basic introduction to algae and… (more)

Wickramage, Shyamila Iroshi Perera

2013-01-01T23:59:59.000Z

110

Parameterization and Sensitivity Analysis of the BIOME–BGC Terrestrial Ecosystem Model: Net Primary Production Controls  

Science Conference Proceedings (OSTI)

Ecosystem simulation models use descriptive input parameters to establish the physiology, biochemistry, structure, and allocation patterns of vegetation functional types, or biomes. For single-stand simulations it is possible to measure required ...

Michael A. White; Peter E. Thornton; Steven W. Running; Ramakrishna R. Nemani

2000-01-01T23:59:59.000Z

111

Improving parameterization of scalar transport through vegetation in a coupled ecosystem-atmosphere model  

E-Print Network (OSTI)

Several regional-scale ecosystem models currently parameterize subcanopy scalar transport using a rough-wall boundary eddy diffusivity formulation. This formulation predicts unreasonably high soil evaporation beneath tall, ...

Link, Percy Anne

2008-01-01T23:59:59.000Z

112

Integration of remote sensing and ecosystem modelling techniques to estimate forest net carbon uptake  

Science Conference Proceedings (OSTI)

Estimates of forest gross primary production (GPP) can be obtained using a parametric model (C-Fix) that combines ground and remotely sensed data. A methodology is presented to convert these GPP estimates into values of net ecosystem exchange (NEE). ...

F. Maselli; M. Chiesi; L. Fibbi; M. Moriondo

2008-04-01T23:59:59.000Z

113

Terrestrial Carbon Sinks for the United States Predicted from MODIS Satellite Data and Ecosystem Modeling  

Science Conference Proceedings (OSTI)

A simulation model based on satellite observations of monthly vegetation cover from the Moderate Resolution Imaging Spectroradiometer (MODIS) was used to estimate monthly carbon fluxes in terrestrial ecosystems of the conterminous United States ...

Christopher Potter; Steven Klooster; Alfredo Huete; Vanessa Genovese

2007-08-01T23:59:59.000Z

114

A Global Eddy-Resolving Coupled Physical-Biological Model: Physical Influences on a Marine Ecosystem in the North Pacific  

Science Conference Proceedings (OSTI)

Physical influences on a marine ecosystem in the open ocean are investigated using a simplified four-component ecosystem model embedded in an eddy-resolving ocean general-circulation model (OGCM). The annual cycle of temperature, nitrate, and phytoplankton ... Keywords: Marine ecosystem, North Pacific, eddy-resolving OGCM, physical processes

Yoshikazu Sasai; Akio Ishida; Hideharu Sasaki; Shintaro Kawahara; Hitoshi Uehara; Yasuhiro Yamanaka

2006-07-01T23:59:59.000Z

115

A Comparison of Tropical Precipitation Simulated by the Community Climate Model with That Measured by the Tropical Rainfall Measuring Mission Satellite  

Science Conference Proceedings (OSTI)

This study evaluates the simulation of tropical precipitation by the Community Climate Model, version 3, (CCM3) developed at the National Center for Atmospheric Research. Monthly mean precipitation rates from an ensemble of CCM3 simulations are ...

J. Craig Collier; Kenneth P. Bowman; Gerald R. North

2004-09-01T23:59:59.000Z

116

Fitting Dynamic Models to the Geosat Sea Level Observations in the Tropical Pacific Ocean. Part I: A Free Wave Model  

Science Conference Proceedings (OSTI)

Free, equatorially trapped sinusoidal wave solutions to a linear model on an equatorial beta plane are used to fit the Geosat altimetric sea level observations in the Tropical Pacific Ocean. The Kalman filter technique is used to estimate the ...

Lee-Lueng Fu; Jorge Vazquez; Claire Perigaud

1991-06-01T23:59:59.000Z

117

Improvement of the NCEP Global Model over the Tropics: An Evaluation of Model Performance during the 1995 Hurricane Season  

Science Conference Proceedings (OSTI)

An evaluation of the performance of the National Centers for Environmental Prediction Medium-Range Forecast Model was made for the large-scale tropical forecasts and hurricane track forecasts during the 1995 hurricane season. The assessment of ...

Naomi Surgi; Hua-Lu Pan; Stephen J. Lord

1998-05-01T23:59:59.000Z

118

Effect of Atlantic Meridional Overturning Circulation on Tropical Atlantic Variability: A Regional Coupled Model Study  

Science Conference Proceedings (OSTI)

A simplified coupled ocean–atmosphere model, where an atmospheric general circulation model (AGCM) is fully coupled to a 2½-layer reduced-gravity ocean model (RGO) over the tropical Atlantic basin, is presented in the context of studying the role ...

Caihong Wen; Ping Chang; Ramalingam Saravanan

2011-07-01T23:59:59.000Z

119

Motion and Evolution of Binary Tropical Cyclones in a Coupled Atmosphere–Ocean Numerical Model  

Science Conference Proceedings (OSTI)

The interaction of binary tropical cyclones (TC) is investigated using a coupled TC-ocean movable nested-grid model. The model consists of an eight-layer atmospheric model in the sigma coordinate system and a three-layer primitive equation ocean ...

Alexander I. Falkovich; Alexander P. Khain; Isaac Ginis

1995-05-01T23:59:59.000Z

120

Global and regional aspects of tropical cyclone activity in the CMIP5 models  

Science Conference Proceedings (OSTI)

Tropical cyclone (TC) activity is analyzed in 14 Coupled Model Intercomparison Project phase 5 (CMIP5) models. The global TC activity in the historical runs is compared with observations. The simulation of TC activity in the CMIP5 models is not as ...

Suzana J. Camargo

Note: This page contains sample records for the topic "tropical ecosystem model" 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

Integrated observations and modelling of greenhouse gas budgets at the ecosystem  

E-Print Network (OSTI)

Mitigation KvR 055/12 Integrated observations and modelling of greenhouse gas budgets Nol | Christy van Beek #12;Integrated observations and modelling of greenhouse gas budgets and modelling of greenhouse gas budgets at the ecosystem level in The Netherlands) was carried out

Stoffelen, Ad

122

Modeling soil quality thresholds to ecosystem recovery at Fort Benning, GA, USA  

SciTech Connect

The objective of this research was to use a simple model of soil carbon (C) and nitrogen (N) dynamics to predict nutrient thresholds to ecosystem recovery on degraded soils at Fort Benning, Georgia, in the southeastern USA. Artillery, wheeled, and tracked vehicle training at military installations can produce soil disturbance and potentially create barren, degraded soils. Ecosystem reclamation is an important component of natural resource management at military installations. Four factors were important to the development of thresholds to recovery of aboveground biomass on degraded soils: (1) initial amounts of aboveground biomass, (2) initial soil C stocks (i.e., soil quality), (3) relative recovery rates of biomass, and (4) soil sand content. Forests and old fields on soils with varying sand content had different predicted thresholds for ecosystem recovery. Soil C stocks at barren sites on Fort Benning were generally below predicted thresholds to 100% recovery of desired future ecosystem conditions defined on the basis of aboveground biomass. Predicted thresholds to ecosystem recovery were less on soils with more than 70% sand content. The lower thresholds for old field and forest recovery on more sandy soils were apparently due to higher relative rates of net soil N mineralization. Calculations with the model indicated that a combination of desired future conditions, initial levels of soil quality (defined by soil C stocks), and the rate of biomass accumulation determine the predicted success of ecosystem recovery on disturbed soils.

Garten Jr, Charles T [ORNL; Ashwood, Tom L [ORNL

2004-12-01T23:59:59.000Z

123

A dynamic object-oriented architecture approach to ecosystem modeling and simulation.  

SciTech Connect

Modeling and simulation in support of adaptive ecosystem management can be better accomplished through a dynamic, integrated, and flexible approach that incorporates scientific and technological components into a comprehensive ecosystem-modeling framework. The Integrated Dynamic Landscape Analysis and Modeling System (IDLAMS) integrates ecological models and decision support techniques, through a geographic information system (GIS)-based framework. The Strategic Environmental Research and Development Program (SERDP) sponsored the development of IDLAMS. Initially built upon a GIS framework, IDLAMS is migrating to an object-oriented (OO) architectural framework. An object-oriented architecture is more flexible and modular. It allows disparate applications and dynamic models to be integrated in a manner that minimizes (or eliminates) the need to rework or recreate the system as new models are added to the suite. In addition, an object-oriented design makes it easier to provide run-time feedback among models, thereby making it a more dynamic tool for exploring and providing insight into the interactions among ecosystem processes. Finally, an object-oriented design encourages the reuse of existing technology because OO-IDLAMS is able to integrate disparate models, databases, or applications executed in their native languages. Reuse is also accomplished through a structured approach to building a consistent and reusable object library. This reusability can substantially reduce the time and effort needed to develop future integrated ecosystem simulations.

Dolph, J. E.; Majerus, K. A.; Sydelko, P. J.; Taxon, T. N.

1999-04-09T23:59:59.000Z

124

An Empirical Model for Predicting the Decay of Tropical Cyclone Wind Speed after Landfall over the Indian Region  

Science Conference Proceedings (OSTI)

An empirical model for predicting the maximum surface wind speed associated with a tropical cyclone after crossing the east coast of India is described. The model parameters are determined from the database of 19 recent cyclones. The model is ...

S. K. Roy Bhowmik; S. D. Kotal; S. R. Kalsi

2005-01-01T23:59:59.000Z

125

RCCM2–BATS Model over Tropical South America: Applications to Tropical Deforestation  

Science Conference Proceedings (OSTI)

A multiyear simulation of the global climate uses a revised version of the National Center for Atmospheric Research (NCAR) Community Climate Model Version 2 (CCM2) coupled to the Biosphere–Atmosphere Transfer Scheme (BATS). It is compared with ...

Andrea N. Hahmann; Robert E. Dickinson

1997-08-01T23:59:59.000Z

126

Evaluation of an ecosystem model for a wheat-maize double cropping system over the North China Plain  

Science Conference Proceedings (OSTI)

A process-based ecosystem model (Vegetation-atmosphere Interface Processes (VIP) model) is expanded, and then validated against three years' biometric, soil moisture and eddy-covariance fluxes data over a winter wheat-summer maize cropping system in ... Keywords: Eddy covariance, Evapotranspiration, Net ecosystem production, Uncertainty, VIP model

Xingguo Mo; Suxia Liu; Zhonghui Lin

2012-06-01T23:59:59.000Z

127

A Comparison of Some Tropical Ocean Models: Hindcast Skill and El Niño Evolution  

Science Conference Proceedings (OSTI)

Tropical Pacific SST hindcasts are examined in the Zebiak and Cane (Lamont), Latif (MPIZ), Oberhuber (OPYC), and GFDL ocean models, each forced by the same wind-stress fields over the 1970–85 time interval. Skill scores reveal that, although all ...

Arthur J. Miller; Tim P. Barnett; Nicholas E. Graham

1993-07-01T23:59:59.000Z

128

Modeling the Effects of Land–Sea Roughness Contrast on Tropical Cyclone Winds  

Science Conference Proceedings (OSTI)

The fifth-generation Pennsylvania State University–National Center for Atmospheric Research (PSU–NCAR) Mesoscale Model (MM5) is used to simulate tropical cyclone (TC) wind distribution near landfall. On an f plane at 15°N, the effects of the ...

Martin L. M. Wong; Johnny C. L. Chan

2007-09-01T23:59:59.000Z

129

The Response of a Linear Model of the Tropical Pacific to Surface Winds from the NCAR General Circulation Model  

Science Conference Proceedings (OSTI)

An experiment in which surface wind stress data from the National Center for Atmospheric Research global circulation model (GCM) was used to drive a simple model of the tropical Pacific is described. First, a 15-year integration of the GCM was ...

Nicholas E. Graham; Tim P. Barnett; Vijay G. Panchang; Ole M. Smedstad; James J. O'Brien; Robert M. Chervin

1989-09-01T23:59:59.000Z

130

The Madden–Julian Oscillation, Barotropic Dynamics, and North Pacific Tropical Cyclone Formation. Part II: Stochastic Barotropic Modeling  

Science Conference Proceedings (OSTI)

A stochastic barotropic model linearized about the 850-mb flow is used to investigate the relationship between wind variations associated with the Madden–Julian oscillation (MJO) and eddy kinetic energy variations in the Tropics. Such a model is ...

Dennis L. Hartmann; Eric D. Maloney

2001-09-01T23:59:59.000Z

131

Predictability of Linear Coupled Systems. Part II: An Application to a Simple Model of Tropical Atlantic Variability  

Science Conference Proceedings (OSTI)

A predictability analysis developed within a general framework of linear stochastic dynamics in a companion paper is applied to a simple coupled climate model of tropical Atlantic variability (TAV). The simple model extends the univariate ...

Ping Chang; R. Saravanan; Faming Wang; Link Ji

2004-04-01T23:59:59.000Z

132

A Modeling Study of the Effect of the Andes on the Summertime Circulation of Tropical South America  

Science Conference Proceedings (OSTI)

A simple linear two level model of the atmosphere is developed which has a reasonable representation of the external and tropically important baroclinic modes. By blocking the lower layer of the model with a meridional wall, the interaction ...

Richard Kleeman

1989-11-01T23:59:59.000Z

133

Explorations of the Annual Mean Heat Budget of the Tropical Indian Ocean. Part I: Studies with an Idealized Model  

Science Conference Proceedings (OSTI)

Annual mean net heat fluxes from ocean general circulation models (OGCMs) are systematically too low in the tropical Indian Ocean, compared to observations. In the models, only some of the geostrophic inflow replacing southward Ekman outflow is ...

J. Stuart Godfrey; Rui-Jin Hu; Andreas Schiller; R. Fiedler

2007-07-01T23:59:59.000Z

134

Time-Mean Response over the Tropical Pacific to Increased C02 in a Coupled Ocean-Atmosphere Model  

Science Conference Proceedings (OSTI)

The time-mean response over the tropical Pacific region to a quadrupling Of CO2 is investigated using a global coupled ocean-atmosphere general circulation model. Tropical Pacific sea surface temperatures (SSTs) rise by about 4°–5°C. The zonal ...

Thomas R. Knutson; Syukuro Manabe

1995-09-01T23:59:59.000Z

135

Effects of diurnal variation on a tropical coupling system: a 2-dimensional coupled ocean-cloud resolving atmosphere modeling study  

Science Conference Proceedings (OSTI)

The effects of diurnal variation on tropical atmospheric and oceanic variability are investigated with a two-dimensional coupled ocean-cloud resolving atmosphere model. The experiment with a time-invariant solar zenith angle is compared to the control ... Keywords: diurnal variation, tropical coupling system

Shouting Gao; Yushu Zhou

2008-05-01T23:59:59.000Z

136

Enhancing terrestrial ecosystem sciences by integrating empirical-modeling approaches  

SciTech Connect

Field and laboratory experiments and observations, along with models, are foundational approaches to scientific inquiry. Integration of these approaches, however, can be an exceedingly difficult challenge because empiricists and modelers often work in communities separated by cultural differences and communication barriers, reflecting a largely independent evolution of these disciplines. To address this challenge, more than 40 participants gathered for a 3-day workshop to discuss how models can best inform empirical experiments, how data can most effectively inform models, and what strategies can be employed to integrate these two approaches. The workshop was convened with the understanding that such a priori exchange between the empirical and modeling communities can maximize intellectual investments and result in high-quality predictive models and more scientific discovery.

Lee, Hanna [National Center for Atmospheric Research (NCAR); Wullschleger, Stan D [ORNL; Luo, Yiqi [University of Oklahoma

2012-01-01T23:59:59.000Z

137

MAIDEN: a model for analyzing ecosystem processes in dendroecology  

E-Print Network (OSTI)

1 Early fall (phase 4) Late fall (phase 5) © 2004 NRC Canadaexisting models, we © 2004 NRC Canada Can. J. For. Res. Vol.forests. Clim. Res. 4: © 2004 NRC Canada Mäkelä, A. , and

Misson, Laurent

2004-01-01T23:59:59.000Z

138

MAIDEN: a model to analyze ecosystem processes in dendroecology  

E-Print Network (OSTI)

1 Early fall (phase 4) Late fall (phase 5) © 2004 NRC Canadaexisting models, we © 2004 NRC Canada Can. J. For. Res. Vol.forests. Clim. Res. 4: © 2004 NRC Canada Mäkelä, A. , and

Misson, Laurent

2004-01-01T23:59:59.000Z

139

Parameterization and sensitivity analysis of the BIOME-BGC terrestrial ecosystem model: Net primary production controls  

E-Print Network (OSTI)

ABSTRACT: Ecosystem simulation models use descriptive input parameters to establish the physiology, biochemistry, structure, and allocation patterns of vegetation functional types, or biomes. For single-stand simulations it is possible to measure required data, but as spatial resolution increases, so too does data unavailability. Generalized biome parameterizations are then required. Undocumented parameter selection and unknown model sensitivity to parameter variation for larger-resolution simulations are currently the major limitations to global and regional modeling. The authors present documented input parameters for a process-based ecosystem simulation model, BIOME– BGC, for major natural temperate biomes. Parameter groups include the following: turnover and mortality; allocation; carbon to nitrogen ratios (C:N); the percent of plant material in labile, cellulose, and lignin pools; leaf morphology; leaf conductance rates and limitations; canopy water interception and light extinction; and the percent of leaf nitrogen in Rubisco (ribulose bisphosphate-1,5-carboxylase/oxygenase) (PLNR). Using climatic and site de-

Michael A. White; Peter E. Thornton; Steven W. Running; Ramakrishna R. Nemani

2000-01-01T23:59:59.000Z

140

Tropical observability and predictability  

E-Print Network (OSTI)

Many studies have investigated tropical data assimilation in the context of global models or specifically for tropical cyclones, but relatively few have focused on the mesoscale predictability and observability of the ...

Whitcomb, Timothy Robert

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical ecosystem model" 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

Statistical modelling of tropical cyclone tracks: non-normal innovations  

E-Print Network (OSTI)

We present results from the sixth stage of a project to build a statistical hurricane model. Previous papers have described our modelling of the tracks, genesis, and lysis of hurricanes. In our track model we have so far employed a normal distribution for the residuals when computing innovations, even though we have demonstrated that their distribution is not normal. Here, we test to see if the track model can be improved by including more realistic non-normal innovations. The results are mixed. Some features of the model improve, but others slightly worsen.

Hall, T; Hall, Tim; Jewson, Stephen

2005-01-01T23:59:59.000Z

142

Description, calibration and sensitivity analysis of the local ecosystem submodel of a global model of carbon and nitrogen cycling and the water balance in the terrestrial biosphere  

Science Conference Proceedings (OSTI)

We have developed a geographically-distributed ecosystem model for the carbon, nitrogen, and water dynamics of the terrestrial biosphere TERRA. The local ecosystem model of TERRA consists of coupled, modified versions of TEM and DAYTRANS. The ecosystem model in each grid cell calculates water fluxes of evaporation, transpiration, and runoff; carbon fluxes of gross primary productivity, litterfall, and plant and soil respiration; and nitrogen fluxes of vegetation uptake, litterfall, mineralization, immobilization, and system loss. The state variables are soil water content; carbon in live vegetation; carbon in soil; nitrogen in live vegetation; organic nitrogen in soil and fitter; available inorganic nitrogen aggregating nitrites, nitrates, and ammonia; and a variable for allocation. Carbon and nitrogen dynamics are calibrated to specific sites in 17 vegetation types. Eight parameters are determined during calibration for each of the 17 vegetation types. At calibration, the annual average values of carbon in vegetation C, show site differences that derive from the vegetation-type specific parameters and intersite variation in climate and soils. From calibration, we recover the average C{sub v} of forests, woodlands, savannas, grasslands, shrublands, and tundra that were used to develop the model initially. The timing of the phases of the annual variation is driven by temperature and light in the high latitude and moist temperate zones. The dry temperate zones are driven by temperature, precipitation, and light. In the tropics, precipitation is the key variable in annual variation. The seasonal responses are even more clearly demonstrated in net primary production and show the same controlling factors.

Kercher, J.R. [Lawrence Livermore National Lab., CA (United States)] [Lawrence Livermore National Lab., CA (United States); Chambers, J.Q. [Lawrence Livermore National Lab., CA (United States)] [Lawrence Livermore National Lab., CA (United States); [California Univ., Santa Barbara, CA (United States). Dept. of Biological Sciences

1995-10-01T23:59:59.000Z

143

Statistical modelling of tropical cyclone genesis: a non-parametric model for the annual distribution  

E-Print Network (OSTI)

As part of a project to develop more accurate estimates of the risks due to tropical cyclones, we describe a non-parametric method for the statistical simulation of the location of tropical cyclone genesis. The method avoids the use of arbitrary grid boxes, and the spatial smoothing of the historical data is constructed optimally according to a clearly defined merit function.

Hall, T; Hall, Tim; Jewson, Stephen

2005-01-01T23:59:59.000Z

144

Statistical modelling of tropical cyclone genesis: a non-parametric model for the annual distribution  

E-Print Network (OSTI)

As part of a project to develop more accurate estimates of the risks due to tropical cyclones, we describe a non-parametric method for the statistical simulation of the location of tropical cyclone genesis. The method avoids the use of arbitrary grid boxes, and the spatial smoothing of the historical data is constructed optimally according to a clearly defined merit function. 1

Tim Hall; Stephen Jewson

2008-01-01T23:59:59.000Z

145

Modeling Soil Quality Thresholds to Ecosystem Recovery at Fort Benning, Georgia, USA  

DOE Green Energy (OSTI)

The objective of this research was to use a simple model of soil C and N dynamics to predict nutrient thresholds to ecosystem recovery on degraded soils at Fort Benning, Georgia, in the southeastern USA. The model calculates aboveground and belowground biomass, soil C inputs and dynamics, soil N stocks and availability, and plant N requirements. A threshold is crossed when predicted soil N supplies fall short of predicted N required to sustain biomass accrual at a specified recovery rate. Four factors were important to development of thresholds to recovery: (1) initial amounts of aboveground biomass, (2) initial soil C stocks (i.e., soil quality), (3) relative recovery rates of biomass, and (4) soil sand content. Thresholds to ecosystem recovery predicted by the model should not be interpreted independent of a specified recovery rate. Initial soil C stocks influenced the predicted patterns of recovery by both old field and forest ecosystems. Forests and old fields on soils with varying sand content had different predicted thresholds to recovery. Soil C stocks at barren sites on Fort Benning generally lie below predicted thresholds to 100% recovery of desired future ecosystem conditions defined on the basis of aboveground biomass (18000 versus 360 g m{sup -2} for forests and old fields, respectively). Calculations with the model indicated that reestablishment of vegetation on barren sites to a level below the desired future condition is possible at recovery rates used in the model, but the time to 100% recovery of desired future conditions, without crossing a nutrient threshold, is prolonged by a reduced rate of forest growth. Predicted thresholds to ecosystem recovery were less on soils with more than 70% sand content. The lower thresholds for old field and forest recovery on more sandy soils are apparently due to higher relative rates of net soil N mineralization in more sandy soils. Calculations with the model indicate that a combination of desired future conditions, initial levels of soil quality (defined by soil C stocks), and the rate of biomass accumulation determines the predicted success of ecosystem recovery on disturbed soils.

Garten Jr., C.T.

2004-03-08T23:59:59.000Z

146

Effects of Diurnal Variations on Tropical Equilibrium States: A Two-Dimensional Cloud-Resolving Modeling Study  

Science Conference Proceedings (OSTI)

Effects of diurnal variations on tropical heat and water vapor equilibrium states are investigated based on hourly data from two-dimensional cloud-resolving simulations. The model is integrated for 40 days and the simulations reach equilibrium ...

Shouting Gao; Yushu Zhou; Xiaofan Li

2007-02-01T23:59:59.000Z

147

Quantitative Assessment of Diurnal Variation of Tropical Convection Simulated by a Global Nonhydrostatic Model without Cumulus Parameterization  

Science Conference Proceedings (OSTI)

This study investigated the resolution dependence of diurnal variation in tropical convective systems represented by a global nonhydrostatic model without cumulus parameterization. This paper describes the detailed characteristics of diurnal ...

Akira T. Noda; Kazuyoshi Oouchi; Masaki Satoh; Hirofumi Tomita

2012-07-01T23:59:59.000Z

148

A Cumulus Parameterization for Climate Studies of the Tropical Atmosphere. Part I: Model Formulation and Sensitivity Tests  

Science Conference Proceedings (OSTI)

A scheme for parameterizing the effects of cumulus convection for the maintenance of the thermodynamic structure of the tropical atmosphere is described. This parameterization is used in a one-dimensional model that represents the vertical ...

Bruce A. Albrecht

1983-09-01T23:59:59.000Z

149

An Air–Sea Interaction Theory for Tropical Cyclones. Part II: Evolutionary Study Using a Nonhydrostatic Axisymmetric Numerical Model  

Science Conference Proceedings (OSTI)

In Part I of this study an analytical model for a steady-state tropical cyclone is constructed on the assumption that boundary-layer air parcels are conditionally neutral to displacements along the angular momentum surfaces of the hurricane ...

Richard Rotunno; Kerry A. Emanuel

1987-02-01T23:59:59.000Z

150

Response of Tropical Cyclones to Idealized Climate Change Experiments in a Global High-Resolution Coupled General Circulation Model  

Science Conference Proceedings (OSTI)

The authors present an assessment of how tropical cyclone activity might change owing to the influence of increased atmospheric carbon dioxide concentrations, using the U.K. High-Resolution Global Environment Model (HiGEM) with N144 resolution (~...

Ray Bell; Jane Strachan; Pier Luigi Vidale; Kevin Hodges; Malcolm Roberts

2013-10-01T23:59:59.000Z

151

Analysis of Idealized Tropical Cyclone Simulations Using the Weather Research and Forecasting Model: Sensitivity to Turbulence Parameterization and Grid Spacing  

Science Conference Proceedings (OSTI)

The Weather Research and Forecasting Advanced Research Model (WRF-ARW) was used to perform idealized tropical cyclone (TC) simulations, with domains of 36-, 12-, and 4-km horizontal grid spacing. Tests were conducted to determine the sensitivity ...

Kevin A. Hill; Gary M. Lackmann

2009-02-01T23:59:59.000Z

152

The Resonant Interaction of a Tropical Cyclone and a Tropopause Front in a Barotropic Model. Part I: Zonally Oriented Front  

Science Conference Proceedings (OSTI)

The interaction of a tropical cyclone and a zonally aligned tropopause front is investigated in an idealized framework. A nondivergent barotropic model is used in which the front is represented by a vorticity step, giving a jetlike velocity ...

Leonhard Scheck; Sarah C. Jones; Martin Juckes

2011-03-01T23:59:59.000Z

153

A Three-Dimensional Barotropic Model of the Response of the Australian North West Shelf to Tropical Cyclones  

Science Conference Proceedings (OSTI)

A three-dimensional barotropic model using a -coordinate or depth transformation, and forced with tropical cyclone wind and atmospheric pressure fields has been applied to the continental shelf and slope regions of the Australian North West ...

C. J. Hearn; P. E. Holloway

1990-01-01T23:59:59.000Z

154

Effects of Saturated and Dry Land Surfaces on the Tropical Circulation and Precipitation in a General Circulation Model  

Science Conference Proceedings (OSTI)

A comprehensive rhomboidal-15 general circulation model with idealized boundary conditions is used to investigate the effects of interactions between the tropical circulation and continental climate on the precipitation distribution. Sea surface ...

Kerry H. Cook; Anand Gnanadesikan

1991-09-01T23:59:59.000Z

155

Convective Influence on the Heat Balance of the Tropical Tropopause Layer: A Cloud-Resolving Model Study  

Science Conference Proceedings (OSTI)

The tropical tropopause layer (TTL), and in particular the cold point tropopause, has been previously suggested as a feature decoupled from convection. Using a cloud-resolving model, the authors demonstrate that convection, in fact, has a cooling ...

Zhiming Kuang; Christopher S. Bretherton

2004-12-01T23:59:59.000Z

156

Impact of a Newtonian Assimilation and Physical Initialization an the Initialization and Prediction by a Tropical Mesoscale Model  

Science Conference Proceedings (OSTI)

This study illustrates the capability of Newtonian nudging and physical initialization in improving the initialized state and forecasts in the Florida State University high-resolution regional tropical mesoscale model. In particular it is shown ...

Kok-Seng Yap

1995-03-01T23:59:59.000Z

157

The Moisture Mode in the Quasi-Equilibrium Tropical Circulation Model. Part II: Nonlinear Behavior on an Equatorial ? Plane  

Science Conference Proceedings (OSTI)

Numerical calculations of a simplified quasi-equilibrium tropical circulation model (QTCM) on the equatorial ? plane have been performed to explore the nonlinear regime of the moisture mode. Sensitivity tests have examined the effects of ...

Masahiro Sugiyama

2009-06-01T23:59:59.000Z

158

Multiscale Convective Wave Disturbances in the Tropics: Insights from a Two-Dimensional Cloud-Resolving Model  

Science Conference Proceedings (OSTI)

Multiscale convective wave disturbances with structures broadly resembling observed tropical waves are found to emerge spontaneously in a nonrotating, two-dimensional cloud model forced by uniform cooling. To articulate the dynamics of these ...

Stefan N. Tulich; Brian E. Mapes

2008-01-01T23:59:59.000Z

159

An Evaluation of Microphysics Fields from Mesoscale Model Simulations of Tropical Cyclones. Part I: Comparisons with Observations  

Science Conference Proceedings (OSTI)

This study presents a framework for comparing hydrometeor and vertical velocity fields from mesoscale model simulations of tropical cyclones with observations of these fields from a variety of platforms. The framework is based on the Yuter and ...

Robert F. Rogers; Michael L. Black; Shuyi S. Chen; Robert A. Black

2007-06-01T23:59:59.000Z

160

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

Note: This page contains sample records for the topic "tropical ecosystem model" 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

Slow Instabilities in Tropical Ocean Basin–Global Atmosphere Models  

Science Conference Proceedings (OSTI)

The effect of ocean boundaries on instability in coupled ocean-natmosphere models is determined. Eigenvalues and eigenvectors are calculated for coupled systems featuring an ocean basin bounded zonally by a flat continent. The atmosphere is ...

Anthony C. Hirst

1988-03-01T23:59:59.000Z

162

Tropical Intraseasonal Oscillations in a Simple Nonlinear Model  

Science Conference Proceedings (OSTI)

This study examines two possible mechanisms responsible for the selection of the preferred period of the Madden and Julian (40–50 day) oscillation. A global two-level nonlinear model with a positive-only CISK-type cumulus heating parameterization ...

Ileana Bladé; Dennis L. Hartmann

1993-09-01T23:59:59.000Z

163

Modeling the Impact of Convective Entrainment on the Tropical Tropopause  

Science Conference Proceedings (OSTI)

Simulations with the Weather Research and Forecasting (WRF) cloud-resolving model of deep moist convective events reveal net cooling near the tropopause (15–18 km above ground), caused by a combination of large-scale ascent and small-scale ...

F. J. Robinson; S. C. Sherwood

2006-03-01T23:59:59.000Z

164

An Assessment of a Model-, Grid-, and Basin-Independent Tropical Cyclone Detection Scheme in Selected CMIP3 Global Climate Models  

Science Conference Proceedings (OSTI)

A novel tropical cyclone (TC) detection technique designed for coarse-resolution models is tested and evaluated. The detector, based on the Okubo–Weiss–Zeta parameter (OWZP), is applied to a selection of Coupled Model Intercomparison Project, ...

K. J. Tory; S. S. Chand; R. A. Dare; J. L. McBride

2013-08-01T23:59:59.000Z

165

Projected changes in late 21st century tropical cyclone frequency in thirteen coupled climate models from the Coupled Model Intercomparison Project Phase 5  

Science Conference Proceedings (OSTI)

Changes in tropical cyclone (TC) frequency under anthropogenic climate change are examined for thirteen global models from the Coupled Model Intercomparison Project Phase 5 (CMIP5), using the OWZP TC detection method developed by the authors in ...

K. J. Tory; S. S. Chand; J. L. McBride; H. Ye; R. A. Dare

166

Modelling the effect of ecosystem change on spawning per recruit of Baltic herring  

E-Print Network (OSTI)

A plea for linking assessment and management to the broader ecosystem state has been made several times in the fisheries literature. The need for ecosystem considerations is obvious for Baltic herring stock which has experienced large fluctuations in growth and natural mortality rate. Biological reference points, based on stock-recruitment data, have gained importance under precautionary approach and the need for more restrictive management. An alternative method for establishing thresholds for recruitment overfishing is spawning per recruit analysis. Within this context, understanding the effects of highly variable natural mortality and growth rate on fishing mortality reference point is of interest. We used Monte Carlo simulations to investigate variation in spawning per recruit caused by varying stock attributes. Causal biological response to changing environmental conditions was created by adjusting the correlation between growth, maturity, and natural mortality. The correlation of the input variables was controlled under three models, assuming future conditions were (1) as

Mika Rahikainen; Sakari Kuikka; Raimo Parmanne

2003-01-01T23:59:59.000Z

167

A Collaborative Ecosystem Model for Metagenomics Data Preservation (MICW - Metagenomics Informatics Challenges Workshop: 10K Genomes at a Time)  

Science Conference Proceedings (OSTI)

EMBL-EBI's Guy Cochrane on "A Collaborative Ecosystem Model for Metagenomics Data Preservation" at the Metagenomics Informatics Challenges Workshop held at the DOE JGI on October 12-13, 2011.

Cochrane, Guy [EMBL-EBI

2011-10-12T23:59:59.000Z

168

Modeling High-Impact Weather and Climate: Lessons From a Tropical Cyclone Perspective  

SciTech Connect

Although the societal impact of a weather event increases with the rarity of the event, our current ability to assess extreme events and their impacts is limited by not only rarity but also by current model fidelity and a lack of understanding of the underlying physical processes. This challenge is driving fresh approaches to assess high-impact weather and climate. Recent lessons learned in modeling high-impact weather and climate are presented using the case of tropical cyclones as an illustrative example. Through examples using the Nested Regional Climate Model to dynamically downscale large-scale climate data the need to treat bias in the driving data is illustrated. Domain size, location, and resolution are also shown to be critical and should be guided by the need to: include relevant regional climate physical processes; resolve key impact parameters; and to accurately simulate the response to changes in external forcing. The notion of sufficient model resolution is introduced together with the added value in combining dynamical and statistical assessments to fill out the parent distribution of high-impact parameters. Finally, through the example of a tropical cyclone damage index, direct impact assessments are presented as powerful tools that distill complex datasets into concise statements on likely impact, and as highly effective communication devices. Capsule: "Combining dynamical modeling of high-impact weather using traditional regional climate models with statistical techniques allows for comprehensive sampling of the full distribution, uncertainty estimation, direct assessment of impacts, and increased confidence in future changes."

Done, James; Holland, Greg; Bruyere, Cindy; Leung, Lai-Yung R.; Suzuki-Parker, Asuka

2012-06-01T23:59:59.000Z

169

SST and North American Tropical Cyclone Landfall: A Statistical Modeling Study  

E-Print Network (OSTI)

We employ a statistical model of North Atlantic tropical cyclone (TC) tracks to investigate the relationship between sea-surface temperature (SST) and North American TC landfall rates. The track model is conditioned on summer SST in the tropical North Atlantic being in either the 19 hottest or the 19 coldest years in the period 1950-2005. For each conditioning many synthetic TCs are generated and landfall rates computed. Compared to direct analysis of historical landfall, the track model reduces the sampling error by projecting information from the entire basin onto the coast. There are 46% more TCs in hot years than cold in the model, which is highly significant compared to random sampling and corroborates well documented trends in North Atlantic TC number in recent decades. In the absence of other effects, this difference results in a significant increase in model landfall rates in hot years, uniform along the coast. Hot-cold differences in the geographic distribution of genesis and in TC propagation do not...

Hall, Timothy

2008-01-01T23:59:59.000Z

170

Precipitation Reproducibility over Tropical Oceans and Its Relationship to the Double ITCZ Problem in CMIP3 and MIROC5 Climate Models  

Science Conference Proceedings (OSTI)

Precipitation reproducibility over the tropical oceans in climate models is examined. Models participating in phase 3 of the Coupled Model Intercomparison Project (CMIP3) and the current (fifth) version Model for Interdisciplinary Research on ...

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

2011-09-01T23:59:59.000Z

171

Potential Impacts of the Saharan Air Layer on Numerical Model Forecasts of North Atlantic Tropical Cyclogenesis  

Science Conference Proceedings (OSTI)

Tropical cyclones have devastating impacts on countries across large parts of the globe, including the Atlantic basin. Thus, forecasting of the genesis of Atlantic tropical cyclones is important, but this problem remains a challenge for ...

Aaron S. Pratt; Jenni L. Evans

2009-04-01T23:59:59.000Z

172

Modeling Return Periods of Tropical Cyclone Intensities in the Vicinity of Hawaii  

Science Conference Proceedings (OSTI)

Tropical cyclones in the vicinity of Hawaii have resulted in great property damage. An estimate of the return periods of tropical cyclone intensities is of particular interest to governments, public interest groups, and private sectors.

Pao-Shin Chu; Jianxin Wang

1998-09-01T23:59:59.000Z

173

Projected Increases in North Atlantic Tropical Cyclone Intensity from CMIP5 Models  

Science Conference Proceedings (OSTI)

Tropical cyclones—particularly intense ones—are a hazard to life and property, so an assessment of the changes in North Atlantic tropical cyclone intensity has important socioeconomic implications. In this study, the authors focus on the ...

Gabriele Villarini; Gabriel A. Vecchi

2013-05-01T23:59:59.000Z

174

High-Resolution Modeling to Assess Tropical Cyclone Activity in Future Climate Regimes  

SciTech Connect

Applied research is proposed with the following objectives: (i) to determine the most likely level of tropical cyclone intensity and frequency in future climate regimes, (ii) to provide a quantitative measure of uncertainty in these predictions, and (iii) to improve understanding of the linkage between tropical cyclones and the planetary-scale circulation. Current mesoscale weather forecasting models, such as the Weather Research and Forecasting (WRF) model, are capable of simulating the full intensity of tropical cyclones (TC) with realistic structures. However, in order to accurately represent both the primary and secondary circulations in these systems, model simulations must be configured with sufficient resolution to explicitly represent convection (omitting the convective parameterization scheme). Most previous numerical studies of TC activity at seasonal and longer time scales have not utilized such explicit convection (EC) model runs. Here, we propose to employ the moving nest capability of WRF to optimally represent TC activity on a seasonal scale using a downscaling approach. The statistical results of a suite of these high-resolution TC simulations will yield a realistic representation of TC intensity on a seasonal basis, while at the same time allowing analysis of the feedback that TCs exert on the larger-scale climate system. Experiments will be driven with analyzed lateral boundary conditions for several recent Atlantic seasons, spanning a range of activity levels and TC track patterns. Results of the ensemble of WRF simulations will then be compared to analyzed TC data in order to determine the extent to which this modeling setup can reproduce recent levels of TC activity. Next, the boundary conditions (sea-surface temperature, tropopause height, and thermal/moisture profiles) from the recent seasons will be altered in a manner consistent with various future GCM/RCM scenarios, but that preserves the large-scale shear and incipient disturbance activity. This will allow (i) a direct comparison of future TC activity that could be expected for an active or inactive season in an altered climate regime, and (ii) a measure of the level of uncertainty and variability in TC activity resulting from different carbon emission scenarios.

Lackmann, Gary

2013-06-10T23:59:59.000Z

175

Superposition of the Neyman–Scott Rectangular Pulses Model and the Poisson White Noise Model for the Representation of Tropical Rain Rates  

Science Conference Proceedings (OSTI)

A point process model for tropical rain rates is developed through the derivation of the third moment expression for a combined point process model. The model is a superposition of a Neyman–Scott rectangular pulse model and a Poisson white noise ...

Mark L. Morrissey

2009-04-01T23:59:59.000Z

176

On the relationship between uncertainties in tropical divergence and the hydrological cycle in global models  

Science Conference Proceedings (OSTI)

A survey of tropical divergence from three GCMs, three global reanalyses and four insitu soundings from field campaigns shows the existence of large uncertainties in the ubiquity of shallow divergent circulation as well as the depth and strength of the deep divergent circulation. More specifically, only two GCMs out of the three GCMs and three global reanalyses show significant shallow divergent circulation, which is present in all in-situ soundings, and of the three GCMs and three global reanalyses, only two global reanalyses have deep divergence profiles that lie within the range of uncertainty of the soundings. The relationships of uncertainties in the shallow and deep divergent circulation to uncertainties in present day and projected strength of the hydrological cycle from the GCMs are assessed. In the tropics and subtropics, deep divergent circulation is the largest contributor to moisture convergence that balances the net precipitation, and inter-model differences in the present day simulations carry over onto the future projections. In comparison to the soundings and reanalyses, the GCMs are found to have deeper and stronger divergent circulation. While these two characteristics of GCM divergence affect the strength of the hydrological cycle, they tend to compensate for each other so that their combined effect is relatively modest.

Hagos, Samson M.; Leung, Lai-Yung R.

2012-01-01T23:59:59.000Z

177

Genesis of Tropical Storm Eugene (2005) from Merging Vortices Associated with ITCZ Breakdowns. Part I: Observational and Modeling Analyses  

Science Conference Proceedings (OSTI)

Although tropical cyclogenesis occurs over all tropical warm ocean basins, the eastern Pacific appears to have the highest frequency of tropical cyclogenesis events per unit area. In this study, tropical cyclogenesis from merging mesoscale ...

Chanh Q. Kieu; Da-Lin Zhang

2008-11-01T23:59:59.000Z

178

Response of tropical cyclones to idealized climate change experiments in a global high resolution coupled general circulation model  

Science Conference Proceedings (OSTI)

We present an assessment of how tropical cyclone activity might change due to the influence of increased atmospheric carbon dioxide concentrations, using the UK’s High Resolution Global Environment Model (HiGEM) with N144 resolution (~90 km in the ...

Ray Bell; Jane Strachan; Pier Luigi Vidale; Kevin Hodges; Malcolm Roberts

179

The Quasi-biennial Oscillation of Ozone in the Tropical Middle Stratosphere: A One-Dimensional Model  

Science Conference Proceedings (OSTI)

A one-dimensional model of the quasi-biennial oscillation (QBO) of ozone in the tropical middle stratosphere is derived based on assumed (observed) zonal wind QBO in a coupled dynamic, radiative/ photochemical system. It is found that the derived ...

Xiu-De Ling; Julius London

1986-12-01T23:59:59.000Z

180

Simulation of microphysical structure associated with tropical cloud clusters using mesoscale model and comparison with TRMM observations  

Science Conference Proceedings (OSTI)

An attempt has been made in the present study to examine the microphysical structure of a non-squall Tropical Cloud Cluster (TCC). Three-dimensional model simulations of cloud microphysical structure associated with a non-squall TCC occurred on 26 October ...

S. Abhilash; K. Mohankumar; S. Das

2008-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical ecosystem model" 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

Biocomplexity of deforestation in the Caparo tropical forest reserve in Venezuela: An integrated multi-agent and cellular automata model  

Science Conference Proceedings (OSTI)

A multi-agent model of social and environmental complexity of deforestation was developed for the Caparo Forest Reserve, Venezuela. It includes three types of agents: settlers, government, and lumber concessionaires. Settlers represent people of limited ... Keywords: Biocomplexity, Deforestation, Multi-agents, Simulation, Tropical forests, Venezuela

Niandry Moreno; Raquel Quintero; Magdiel Ablan; Rodrigo Barros; Jacinto Dávila; Hirma Ramírez; Giorgio Tonella; Miguel F. Acevedo

2007-05-01T23:59:59.000Z

182

Effects of Downdrafts and Mesoscale Convective Organization on the Heat and Moisture Budgets of Tropical Cloud Clusters. Part I: A Diagnostic Cumulus Ensemble Model  

Science Conference Proceedings (OSTI)

A diagnostic cumulus ensemble model is developed to study the effects of convective-scale downdrafts and mesoscale convective organization on the heat and moisture budgets of tropical cloud clusters. The model adopts the spectral representation ...

Ming-Dean Cheng

1989-06-01T23:59:59.000Z

183

Multiscale Interactions in the Life Cycle of a Tropical Cyclone Simulated in a Global Cloud-System-Resolving Model. Part II: System-Scale and Mesoscale Processes  

Science Conference Proceedings (OSTI)

The life cycle of Tropical Storm Isobel was simulated reasonably well in the Nonhydrostatic Icosahedral Atmospheric Model (NICAM), a global cloud-system-resolving model. The evolution of the large-scale circulation and the storm-scale structure ...

Hironori Fudeyasu; Yuqing Wang; Masaki Satoh; Tomoe Nasuno; Hiroaki Miura; Wataru Yanase

2010-12-01T23:59:59.000Z

184

Agent-Based Modelling of Socio-Ecosystems: A Methodology for the Analysis of Adaptation to Climate Change  

Science Conference Proceedings (OSTI)

The integrated-environmental, economic and social-analysis of climate change calls for a paradigm shift as it is fundamentally a problem of complex, bottom-up and multi-agent human behaviour. There is a growing awareness that global environmental change ... Keywords: Agent-Based Modelling, Bottom-Up Exploration, Climate Change Adaptation, Socio-Ecosystems, Sustainability Strategies

Stefano Balbi; Carlo Giupponi

2010-10-01T23:59:59.000Z

185

Fitting Dynamic Models to the Geosat Sea Level Observations in the Tropical Pacific Ocean. Part II: A Linear, Wind-driven Model  

Science Conference Proceedings (OSTI)

The Geosat altimeter sea level observations in the tropical Pacific Ocean are used to evaluate the Performance of a linear wind-driven equatorial wave model. The question posed is the extent to which such a model can describe the observed sea ...

Lee-Lueng Fu; Ichiro Fukumori; Robert N. Miller

1993-10-01T23:59:59.000Z

186

Tropical Sensitivity of a Coupled Model to Specified ISCCP Low Clouds  

Science Conference Proceedings (OSTI)

The seasonal cycle of SST observed in the eastern equatorial Pacific is poorly simulated by many ocean–atmosphere coupled GCMs. This deficiency may be partly due to an incorrect prediction of tropical marine stratocumulus (MSc). To explore this ...

C. T. Gordon; A. Rosati; R. Gudgel

2000-07-01T23:59:59.000Z

187

Numerical Modeling of an Orographically Enhanced Precipitation Event Associated with Tropical Storm Rachel over Taiwan  

Science Conference Proceedings (OSTI)

An orographic rainfall event that occurred on 6–7 August 1999 during the passage of Tropical Storm (TS) Rachel over Taiwan is investigated by performing triply nested, nonhydrostatic numerical simulations using the Naval Research Laboratory's (...

Sen Chiao; Yuh-Lang Lin

2003-04-01T23:59:59.000Z

188

An Analysis of NCEP Tropical Cyclone Vitals and Potential Effects on Forecasting Models  

Science Conference Proceedings (OSTI)

This study analyzes the Tropical Cyclone Vitals Database (TCVitals), which contains cyclone location, intensity, and structure information, generated in real time by forecasters. These data are used to initialize cyclones in several NCEP ...

Sam Trahan; Lynn Sparling

2012-06-01T23:59:59.000Z

189

Evaluation of an Analytical Model for the Maximum Intensity of Tropical Cyclones  

Science Conference Proceedings (OSTI)

Several studies have shown that the intensity of numerically simulated tropical cyclones can exceed (by 50%) a theoretical upper limit. To investigate the cause, this study evaluates the underlying components of Emanuel’s commonly cited analytic ...

George H. Bryan; Richard Rotunno

2009-10-01T23:59:59.000Z

190

Tropical Cyclone Climatology in a 10-km Global Atmospheric GCM: Toward Weather-Resolving Climate Modeling  

Science Conference Proceedings (OSTI)

Northern Hemisphere tropical cyclone (TC) activity is investigated in multiyear global climate simulations with the ECMWF Integrated Forecast System (IFS) at 10-km resolution forced by the observed records of sea surface temperature and sea ice. ...

Julia V. Manganello; Kevin I. Hodges; James L. Kinter III; Benjamin A. Cash; Lawrence Marx; Thomas Jung; Deepthi Achuthavarier; Jennifer M. Adams; Eric L. Altshuler; Bohua Huang; Emilia K. Jin; Cristiana Stan; Peter Towers; Nils Wedi

2012-06-01T23:59:59.000Z

191

A Model of Rossby Waves Linked to Submonthly Convection over the Eastern Tropical Pacific  

Science Conference Proceedings (OSTI)

Equatorward-propagating wave trains in the upper troposphere are observed to be associated with deep convection over the eastern tropical Pacific on the submonthly timescale during northern winter. The convection occurs in the regions of ascent ...

Adrian J. Matthews; George N. Kiladis

2000-12-01T23:59:59.000Z

192

Objective Debiasing for Improved Forecasting of Tropical Cyclone Intensity with a Global Circulation Model  

Science Conference Proceedings (OSTI)

The damage potential of a tropical cyclone is proportional to a power (generally greater than one) of intensity, which demands high accuracy in forecasting intensity for managing this natural disaster. However, the current skill in forecasting ...

P. Goswami; S. Mallick; K. C. Gouda

2011-08-01T23:59:59.000Z

193

Ensemble Forecasting of Tropical Cyclone Motion Using a Barotropic Model. Part II: Perturbations of the Vortex  

Science Conference Proceedings (OSTI)

In Part I of this study, the technique of ensemble forecasting is applied to the problem of tropical cyclone motion prediction by perturbing the environmental flow. In this part, the focus is shifted to perturbation of the vortex structure. The ...

Kevin K. W. Cheung; Johnny C. L. Chan

1999-11-01T23:59:59.000Z

194

Validation of a Tropical Cyclone Steering Response Function with a Barotropic Adjoint Model  

Science Conference Proceedings (OSTI)

The steering of a tropical cyclone (TC) vortex is commonly understood as the advection of the TC vortex by an “environmental wind.” In past studies, the environmental steering wind vector has been defined by the horizontal and vertical averaging ...

Brett T. Hoover; Michael C. Morgan

2010-06-01T23:59:59.000Z

195

Observed and Modeled Wind and Water-Level Response from Tropical Storm Marco (1990)  

Science Conference Proceedings (OSTI)

The Hurricane Research Division (HRD) analyzes surface wind fields in tropical storms and hurricanes using surface wind observations and aircraft flight-level wind measurements in the vicinity of the storms. The analyzed surface wind fields for ...

Sam H. Houston; Mark D. Powell

1994-09-01T23:59:59.000Z

196

Tropical Cyclone Data Impact Studies: Influence of Model Bias and Synthetic Observations  

Science Conference Proceedings (OSTI)

The impacts of assimilating dropwindsonde data and enhanced atmospheric motion vectors (AMVs) on tropical cyclone track forecasts are examined using the Navy global data assimilation and forecasting systems. Enhanced AMVs have the largest impact ...

Carolyn A. Reynolds; Rolf Langland; Patricia M. Pauley; Christopher Velden

2013-12-01T23:59:59.000Z

197

Surface Wind over Tropical Oceans: Diagnosis of the Momentum Balance, and Modeling the Linear Friction Coefficient  

Science Conference Proceedings (OSTI)

Previous diagnostic studies of surface wind momentum balances over tropical oceans showed that, under a linear friction assumption, the meridional friction coefficient is two to three times larger than the zonal friction coefficient, and that ...

John C. H. Chiang; Stephen E. Zebiak

2000-05-01T23:59:59.000Z

198

A Model-Based Assessment and Design of a Tropical Indian Ocean Mooring Array  

Science Conference Proceedings (OSTI)

A series of observing system simulation experiments (OSSEs) are performed for the tropical Indian Ocean (±15° from the equator) using a simple analysis system. The analysis system projects an array of observations onto the dominant empirical ...

Peter R. Oke; Andreas Schiller

2007-07-01T23:59:59.000Z

199

The Formation of Comma Vortices in a Tropical Numerical Simulation Model  

Science Conference Proceedings (OSTI)

A detailed analysis of a numerically simulated tropical disturbance displays a comma-shaped pattern at the mature stage in the low-level vorticity, surface convergence, mid-level upward motion and precipitation fields.

Robert E. Tuleya; Yoshio Kurihara

1984-03-01T23:59:59.000Z

200

Using Mesoscale Simulations to Train Statistical Models of Tropical Cyclone Intensity over Land  

Science Conference Proceedings (OSTI)

The decay of tropical cyclones after landfall is a key factor in estimating the extent of the hazard overland. Yet our current understanding of this decay is challenged by the low frequency of past events. Consequently, one cannot rely solely ...

Augustin Colette; Nadja Leith; Vincent Daniel; Enrica Bellone; David S. Nolan

2010-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical ecosystem model" 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

Tropical Cyclone Data Impact Studies: Influence of Model Bias and Synthetic Observations  

Science Conference Proceedings (OSTI)

The impacts of assimilating dropwindsonde data and enhanced atmospheric motion vectors (AMVs) on tropical cyclone track forecasts are examined using the Navy global data assimilation and forecasting systems. Enhanced AMVs have the largest impact ...

Carolyn A. Reynolds; Rolf Langland; Patricia M. Pauley; Christopher Velden

202

Effect of Atlantic Meridional Overturning Circulation Changes on Tropical Atlantic Sea Surface Temperature Variability: A 2½-Layer Reduced-Gravity Ocean Model Study  

Science Conference Proceedings (OSTI)

Previous coupled climate model simulations reveal that a dipole-like SST pattern with cooler (warmer) temperature over the north (south) tropical Atlantic emerges in response to a slowdown of the Atlantic meridional overturning circulation (AMOC)...

Caihong Wen; Ping Chang; Ramalingam Saravanan

2010-01-01T23:59:59.000Z

203

The Slow Sea Surface Temperature Mode and the Fast-Wave Limit: Analytic Theory for Tropical Interannual Oscillations and Experiments in a Hybrid Coupled Model  

Science Conference Proceedings (OSTI)

A modified shallow water model with simplified mixed layer dynamics and a sea surface temperature (SST) equation is employed to gain a theoretical understanding of the modes and mechanisms of coupled air-sea interaction in the tropics. ...

J. David Neelin

1991-02-01T23:59:59.000Z

204

Using Satellite Ocean Color Data to Derive an Empirical Model for the Penetration Depth of Solar Radiation (Hp) in the Tropical Pacific Ocean  

Science Conference Proceedings (OSTI)

Satellite-based ocean color measurements indicate clear evidence for bioclimate interactions in the tropical Pacific associated with El Niño–Southern Oscillation (ENSO). Recent modeling studies have demonstrated that ocean biology can potentially ...

Rong-Hua Zhang; Dake Chen; Guihua Wang

2011-07-01T23:59:59.000Z

205

Simple Empirical Models for Estimating the Increase in the Central Pressure of Tropical Cyclones after Landfall along the Coastline of the United States  

Science Conference Proceedings (OSTI)

Modeling the increase in the central pressure of tropical cyclones following landfall plays a critical role in the estimation of the hurricane wind hazard at locations removed from the coastline. This paper describes the development of simple ...

Peter J. Vickery

2005-12-01T23:59:59.000Z

206

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

207

The Impact of Horizontal Grid Spacing on the Microphysical and Kinematic Structures of Strong Tropical Cyclones Simulated with the WRF-ARW Model  

Science Conference Proceedings (OSTI)

Using the Advanced Weather Research and Forecasting numerical model, the impact of horizontal grid spacing on the microphysical and kinematic structure of a numerically simulated tropical cyclone (TC), and their relationship to storm intensity ...

Alexandre O. Fierro; Robert F. Rogers; Frank D. Marks; David S. Nolan

2009-11-01T23:59:59.000Z

208

Calibrating the Simple Biosphere Model for Amazonian Tropical Forest Using Field and Remote Sensing Data. Part I: Average Calibration with Field Data  

Science Conference Proceedings (OSTI)

This paper describes the operation and calibration of the simple biosphere model (SiB) of Sellers et al. using micrometeorological and hydrological measurements taken in and above tropical forest in the central Amazon basin. The paper provides:

Piers J. Sellers; W. James Shuttleworth; Jeff L. Dorman; Amnon Dalcher; John M. Roberts

1989-08-01T23:59:59.000Z

209

The Moisture Mode in the Quasi-Equilibrium Tropical Circulation Model. Part I: Analysis Based on the Weak Temperature Gradient Approximation  

Science Conference Proceedings (OSTI)

The moisture mode in a simplified version of the quasi-equilibrium tropical circulation model (QTCM) of Neelin and Zeng is analyzed. Perturbation expansion based on the ratio of temperature tendency to adiabatic cooling simplifies the system and ...

Masahiro Sugiyama

2009-06-01T23:59:59.000Z

210

Statistical modelling of tropical cyclone tracks: modelling the autocorrelation in track shape  

E-Print Network (OSTI)

We describe results from the third stage of a project to build a statistical model for hurricane tracks. In the first stage we modelled the unconditional mean track. In the second stage we modelled the unconditional variance of fluctuations around the mean. Now we address the question of how to model the autocorrelations in the standardised fluctuations. We perform a thorough diagnostic analysis of these fluctuations, and fit a type of AR(1) model. We then assess the goodness of fit of this model in a number of ways, including an out-of-sample comparison with a simpler model, an in-sample residual analysis, and a comparison of simulated tracks from the model with the observed tracks. Broadly speaking, the model captures the behaviour of observed hurricane tracks. In detail, however, there are a number of systematic errors.

Hall, T; Hall, Tim; Jewson, Stephen

2005-01-01T23:59:59.000Z

211

Statistical modelling of tropical cyclone tracks: a comparison of models for the variance of trajectories  

E-Print Network (OSTI)

We describe results from the second stage of a project to build a statistical model for hurricane tracks. In the first stage we modelled the unconditional mean track. We now attempt to model the unconditional variance of fluctuations around the mean. The variance models we describe use a semi-parametric nearest neighbours approach in which the optimal averaging length-scale is estimated using a jack-knife out-of-sample fitting procedure. We test three different models. These models consider the variance structure of the deviations from the unconditional mean track to be isotropic, anisotropic but uncorrelated, and anisotropic and correlated, respectively. The results show that, of these models, the anisotropic correlated model gives the best predictions of the distribution of future positions of hurricanes.

Hall, T; Hall, Tim; Jewson, Stephen

2005-01-01T23:59:59.000Z

212

Interannual Tropical Rainfall Variability in General Circulation Model Simulations Associated with the Atmospheric Model Intercomparison Project  

Science Conference Proceedings (OSTI)

The interannual variability of rainfall over the Indian subcontinent, the African Sahel, and the Nordeste region of Brazil have been evaluated in 32 models for the period 1979–88 as part of the Atmospheric Model Intercomparison Project (AMIP). ...

K. R. Sperber; T. N. Palmer

1996-11-01T23:59:59.000Z

213

Statistical modelling of tropical cyclone tracks: a semi-parametric model for the mean trajectory  

E-Print Network (OSTI)

We present a statistical model for the unconditional mean tracks of hurricanes. Our model is a semi-parametric scheme that averages together observed hurricane displacements. It has a single parameter that defines the averaging length scale, and we derive the optimum value for this parameter using a jackknife. The main purpose of this model is as a starting point for developing a statistical model of hurricanes for use in the estimation of the wind, rainfall and flooding risks. The model also acts as an optimal filtering tool for estimating mean hurricane tracks.

Hall, T; Hall, Tim; Jewson, Stephen

2005-01-01T23:59:59.000Z

214

ELSEVIER Ecological Modelling 101 (1997) 61-78 Modeling nitrogen saturation in forest ecosystems in response  

E-Print Network (OSTI)

) and Harvard Forest (Petersham, MA). It is then used to predict transient responses in function resulting from, Petersham, MA. The validated model is then used to predict rates of change in N cycling and N leaching two sites, The Harvard Forest, Petersham, MA and The Hubbard Brook Experimental Forest, near West

New Hampshire, University of

215

Using Variable Resolution Meshes to Model Tropical Cyclones in the Community Atmosphere Model  

Science Conference Proceedings (OSTI)

A statically-nested, variable-mesh option has recently been introduced into the Community Atmosphere Model’s (CAM) Spectral Element (SE) dynamical core that has become the default in CAM version 5.3. This paper presents a series of tests of ...

Colin M. Zarzycki; Christiane Jablonowski; Mark A. Taylor

216

Methane Fluxes Between Terrestrial Ecosystems and the Atmosphere at Northern High Latitudes During the Past Century: A retrospective analysis with a process-based biogeochemistry model  

E-Print Network (OSTI)

We develop and use a new version of the Terrestrial Ecosystem Model (TEM) to study how rates of methane (CH4) emissions and consumption in high-latitude soils of the Northern Hemisphere have changed over the past century ...

Zhuang, Qianlai.

217

Evaluation of a Two-Source Snow-Vegetation Energy Balance Model for Estimating Surface Energy Fluxes in a Rangeland Ecosystem  

Science Conference Proceedings (OSTI)

The utility of a snow-vegetation energy balance model for estimating surface energy fluxes is evaluated with field measurements at two sites in a rangeland ecosystem in southwestern Idaho during the winter of 2007: one site dominated by aspen ...

Cezar Kongoli; William P. Kustas; Martha C. Anderson; John M. Norman; Joseph G. Alfieri; Gerald N. Flerchinger; Danny Marks

218

Research Article: Quantitative versus qualitative modeling: A complementary approach in ecosystem study  

Science Conference Proceedings (OSTI)

Natural disturbance or human perturbation act upon ecosystems by changing some dynamical parameters of one or more species. Foreseeing these modifications is necessary before embarking on an intervention: predictions may help to assess management options ... Keywords: Community matrix, Food webs, Loop analysis, Network analysis, Predictions

C. Bondavalli; S. Favilla; A. Bodini

2009-02-01T23:59:59.000Z

219

Modeling the Direct and Indirect Effects of Atmospheric Aerosols on Tropical Cyclones  

E-Print Network (OSTI)

The direct and indirect effects of aerosols on the hurricane ‘Katrina’ have been investigated using the WRF model with a two-moment bulk microphysical scheme and modified Goddard shortwave radiation scheme. Simulations of the hurricane ‘Katrina’ are conducted under the three aerosol scenarios: 1) the clean case with an aerosol number concentration of 200 cm-1, 2) the polluted case with a number concentration of 1000 cm-1, and 3) the aerosol radiative effects (AR) case with same aerosol concentration as polluted case but with a modified shortwave radiation scheme. The polluted and AR cases have much larger amounts of cloud water and water vapor in troposphere, and the increased cloud water can freeze to produce ice water paths. A tropical cyclone in dirty and dusty air has active rainbands outside the eyewall due to aerosol indirect effects. The aerosol direct effect can lead to the suppressing of convection and weakening of updraft intensity by warming the troposphere and cooling the surface temperature. However, these thermal changes in atmosphere are concerned with the enhanced amounts of cloud hydrometeors and modification of downdraft and corresponding the low level winds in rainband regions. Thus, the AR case can produce the enhanced precipitation even in the weakest hurricane. When comparing the model performance between aerosol indirect and direct effect by ensemble experiments, the adjustment time of the circulation due to modification of the aerosol radiative forcing by aerosol layers may take a longer time than the hurricane lifetime, and the results from the simulated hurricane show that it is more sensitive to aerosol indirect effects which are related to the cloud microphysics process changes. From this aerosol study, we can suggest that aerosols can influence the cloudiness, precipitation, and intensity of hurricanes significantly, and there may be different results in the meso-scale convective clouds cases. The hurricane system is a large and complex convective system with enormous heating energy and moistures. Moreover, relationships between various hydrometeors in hurricane systems are difficult to isolate and thus, it needs further study with more realistic cloud microphysical processes, aerosol distributions, and parameterizations.

Lee, Keun-Hee

2011-12-01T23:59:59.000Z

220

Tropical forest responses to increasing [CO2]: current knowledge and opportunities for future research  

Science Conference Proceedings (OSTI)

Elevated atmospheric [CO2] (ca) will undoubtedly affect the metabolism of tropical forests worldwide; however, critical aspects of how tropical forests will respond remain largely unknown. Here we review the current state of knowledge about physiological and ecological responses, with the aim of providing a framework that can help to guide future experimental research. Modelling studies have indicated that elevated ca can potentially stimulate photosynthesis more in the tropics than at higher latitudes, because suppression of photorespiration by elevated ca increases with temperature. However, canopy leaves in tropical forests could also potentially reach a high temperature threshold under elevated ca that will moderate the rise in photosynthesis. Belowground responses, including fine root production, nutrient foraging, and soil organic matter processing, will be especially important to the integrated ecosystem response to elevated CO2. Water-use efficiency will increase as ca rises, potentially impacting upon soil moisture status and nutrient availability. Recruitment may be differentially altered for some functional groups, potentially decreasing ecosystem carbon storage. Whole-forest CO2 enrichment experiments are urgently needed to test predictions of tropical forest functioning under elevated ca. Smaller scale experiments in the understory and in gaps would also be informative, and could provide stepping stones toward stand-scale manipulations.

Cernusak, Lucas [Australian National University, Canberra, Australia; Winter, Klaus [Smithsonian Tropical Research Institute; Dalling, James [University of Illinois, Urbana-Champaign; Holtum, Joseph [James Cook University; Jaramillo, Carlos [Smithsonian Tropical Research Institute; Korner, Christian [University of Basel; Leakey, Andrew D.B. [University of Illinois; Norby, Richard J [ORNL; Poulter, Benjamin [Laboratoire des Sciences du Climat et de l'Environement, France; Turner, Benjamin [Smithsonian Tropical Research Institute; Wright, S. Joseph [Smithsonian Tropical Research Institute

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical ecosystem model" 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

Adjustment of the Remote Tropical Climate to El Niño Conditions  

Science Conference Proceedings (OSTI)

The adjustment of the tropical climate outside the Pacific (the “remote Tropics”) to the abrupt onset of El Niño conditions is examined in a tropical atmosphere model that assumes simplified vertical structure and quasi-equilibrium (QE) ...

Benjamin R. Lintner; John C. H. Chiang

2007-06-01T23:59:59.000Z

222

Characterizing the performance of ecosystem models across time scales: A spectral analysis of the North American Carbon Program site-level synthesis  

Science Conference Proceedings (OSTI)

Ecosystem models are important tools for diagnosing the carbon cycle and projecting its behavior across space and time. Most assessments of model performance occur at individual temporal scales, but ecosystems respond to drivers at multiple time scales. Spectral methods, such as wavelet analyses, present an alternative approach that enables the identification of the dominant time scales contributing to model performance in the frequency domain. In this study we used wavelet analyses to synthesize the performance of twenty-one ecosystem models at nine eddy-covariance towers as part of the North American Carbon Program's site-level inter-comparison. This study expands upon previous single-site and single-model analyses to determine what patterns of model failure are consistent across a diverse range of models and sites.

Dietze, Michael; Vargas, Rodrigo; Richardson, Andrew D.; Stoy, Paul C.; Barr, Alan; Anderson, Ryan; Arain, M. A.; Baker, Ian; Black, T. Andrew; Chen, Jing Ming; Ciais, Philippe; Flanagan, Lawrence; Gough, Christopher; Grant, R. F.; Hollinger, D.; Izaurralde, Roberto C.; Kucharik, Chris; Lafleur, Peter; Liu, Shuguang; Lokupitiya, Erandathie; Luo, Yiqi; Munger, J. W.; Peng, Changhui; Poulter, Benjamin; Price, David T.; Ricciuto, Daniel M.; Riley, William; Sahoo, Alok Kumar; Schaefer, Kevin; Suyker, Andrew E.; Tian, Hanqin; Tonitto, Christine; Verbeeck, Hans; Verma, Shashi B.; Wang, Weifeng; Weng, Ensheng

2011-12-20T23:59:59.000Z

223

The REFLEX project: Comparing different algorithms and implementations for the inversion of a terrestrial ecosystem model against eddy covariance data  

DOE Green Energy (OSTI)

We describe a model-data fusion (MDF) inter-comparison project (REFLEX), which compared various algorithms for estimating carbon (C) model parameters consistent with both measured carbon fluxes and states and a simple C model. Participants were provided with the model and with both synthetic net ecosystem exchange (NEE) ofCO2 and leaf area index (LAI) data, generated from the model with added noise, and observed NEE and LAI data from two eddy covariance sites. Participants endeavoured to estimate model parameters and states consistent with the model for all cases over the two years for which data were provided, and generate predictions for one additional year without observations. Nine participants contributed results using Metropolis algorithms, Kalman filters and a genetic algorithm. For the synthetic data case, parameter estimates compared well with the true values. The results of the analyses indicated that parameters linked directly to gross primary production (GPP) and ecosystem respiration, such as those related to foliage allocation and turnover, or temperature sensitivity of heterotrophic respiration,were best constrained and characterised. Poorly estimated parameters were those related to the allocation to and turnover of fine root/wood pools. Estimates of confidence intervals varied among algorithms, but several algorithms successfully located the true values of annual fluxes from synthetic experiments within relatively narrow 90% confidence intervals, achieving>80% success rate and mean NEE confidence intervals <110 gCm-2 year-1 for the synthetic case. Annual C flux estimates generated by participants generally agreed with gap-filling approaches using half-hourly data. The estimation of ecosystem respiration and GPP through MDF agreed well with outputs from partitioning studies using half-hourly data. Confidence limits on annual NEE increased by an average of 88% in the prediction year compared to the previous year, when data were available. Confidence intervals on annual NEE increased by 30% when observed data were used instead of synthetic data, reflecting and quantifying the addition of model error. Finally, our analyses indicated that incorporating additional constraints, using data on C pools (wood, soil and fine roots) would help to reduce uncertainties for model parameters poorly served by eddy covariance data.

Fox, Andrew [University of Sheffield; Williams, Mathew [University of Edinburgh; Richardson, Andrew D. [Harvard University; Cameron, David [Centre for Ecology and Hydrology, Bush Estate; Gove, Jeffrey H. [USDA Forest Service; Quaife, Tristan [University College, London; Ricciuto, Daniel M [ORNL; Reichstein, Markus [Max Planck Institute for Biogeochemistry; Tomelleri, Enrico [Max Planck Institute for Biogeochemistry; Trudinger, Cathy [CSIRO Marine and Atmospheric Research; Van Wijk, Mark T. [Wageningen University and Research Centre, The Netherlands

2009-10-01T23:59:59.000Z

224

Diagnosing Forecast Errors in Tropical Cyclone Motion  

Science Conference Proceedings (OSTI)

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

Thomas J. Galarneau Jr.; Christopher A. Davis

2013-02-01T23:59:59.000Z

225

Temperature Advection by Tropical Instability Waves  

Science Conference Proceedings (OSTI)

A numerical model of the tropical Pacific Ocean is used to investigate the processes that cause the horizontal temperature advection of tropical instability waves (TIWs). It is found that their temperature advection cannot be explained by the ...

Markus Jochum; Raghu Murtugudde

2006-04-01T23:59:59.000Z

226

Distribution of Tropical Tropospheric Water Vapor  

Science Conference Proceedings (OSTI)

Utilizing a conceptual model for tropical convection and observational data for water vapor, the maintenance of the vertical distribution of the tropical tropospheric water vapor is discussed. While deep convection induces large-scale subsidence ...

De-Zheng Sun; Richard S. Lindzen

1993-06-01T23:59:59.000Z

227

Simulation of the tropical Pacific climate with a coupled ocean - atmosphere general circulation model. Part II: Interannual variability  

Science Conference Proceedings (OSTI)

Two multiyear simulations with a coupled ocean-atmosphere general circulation model (GCM)-totaling 45 years-are used to investigate interannual variability at the equator. The model consists of the UCLA global atmospheric GCM coupled to the GFDL oceanic GCM, dynamically active over the tropical Pacific. Multichannel singular spectrum analysis along the equator identifies ENSO-like quasi-biennial (QB) and quasi-quadrennial (QQ) modes. Both consist of predominantly standing oscillations in sea surface temperature and zonal wind stress that peak in the central or east Pacific, accompanied by an oscillation in equatorial thermocline depth that is characterized by a phase shift of about 90{degrees} across the basin, with west leading east. Simulated interannual variability is weaker than observed in both simulations. One of these is dominated by the QB, the other by the QQ mode, although the two differ only in details of the surface-layer parameterizations. 42 refs., 19 figs., 2 tabs.

Robertson, A.W.; Ma, C.C.; Ghil, M. [Univ. of California, Los Angeles, CA (United States)] [and others

1995-05-01T23:59:59.000Z

228

Explorations of the Annual Mean Heat Budget of the Tropical Indian Ocean. Part II: Studies with a Simplified Ocean General Circulation Model  

Science Conference Proceedings (OSTI)

Present-day OGCMs give low values of annual mean net heat flux (AMNHF) in the tropical Indian Ocean, compared to climatologies. AMNHF generation is examined in an open-boundary model of this region with realistic coastlines. In the first two of ...

Rui-Jin Hu; J. Stuart Godfrey

2007-07-01T23:59:59.000Z

229

Response of ice and liquid water paths of tropical cyclones to global warming simulated by a global nonhydrostatic model with explicit cloud microphysics  

Science Conference Proceedings (OSTI)

Cloud feedback plays a key role in the future climate projection. Using global non-hydrostatic model (GNHM) simulation data for a present-day (CTL) and a warmer (GW) experiment, we estimate the contribution of tropical cyclones (TC) to ice/liquid ...

Yohei Yamada; Masaki Satoh

230

Tropical Cyclone Cloudbands  

Science Conference Proceedings (OSTI)

The outer cloudband structure of a tropical cyclone is kinematically treated as the manifestation of a forced set of waves stationary with respect to the cyclone. When the cyclone wind field is modeled as a Rankine vortex and the cloudbands are ...

Tom Beer; L. Giannini

1980-07-01T23:59:59.000Z

231

Multiscale Interactions in the Life Cycle of a Tropical Cyclone Simulated in a Global Cloud-System-Resolving Model. Part I: Large-Scale and Storm-Scale Evolutions  

Science Conference Proceedings (OSTI)

The Nonhydrostatic Icosahedral Atmospheric Model (NICAM), a global cloud-system-resolving model, successfully simulated the life cycle of Tropical Storm Isobel that formed over the Timor Sea in the austral summer of 2006. The multiscale ...

Hironori Fudeyasu; Yuqing Wang; Masaki Satoh; Tomoe Nasuno; Hiroaki Miura; Wataru Yanase

2010-12-01T23:59:59.000Z

232

Evaluation of a Process-Based Agro-Ecosystem Model (Agro-IBIS) across the U.S. Corn Belt: Simulations of the Interannual Variability in Maize Yield  

Science Conference Proceedings (OSTI)

A process-based terrestrial ecosystem model, Agro-IBIS, was used to simulate maize yield in a 13-state region of the U.S. Corn Belt from 1958 to 1994 across a 0.5° terrestrial grid. For validation, county-level census [U.S. Department of ...

Christopher J. Kucharik

2003-12-01T23:59:59.000Z

233

Interactions of the Tropical Oceans  

Science Conference Proceedings (OSTI)

The authors have investigated the interactions of the tropical oceans on interannual timescales by conducting a series of uncoupled atmospheric and oceanic general circulation experiments and hybrid-coupled model simulations. The results ...

M. Latif; T. P. Barnett

1995-04-01T23:59:59.000Z

234

Climate and the Tropical Oceans  

Science Conference Proceedings (OSTI)

An attempt is made to determine the role of the ocean in establishing the mean tropical climate and its sensitivity to radiative perturbations. A simple two-box energy balance model is developed that includes ocean heat transports as an ...

Amy Clement; Richard Seager

1999-12-01T23:59:59.000Z

235

A Conceptual Model for the Influence of TUTT Cells on Tropical Cyclone Motion in the Northwest Pacific Ocean  

Science Conference Proceedings (OSTI)

Eleven (10 Pacific, 1 Atlantic) tropical cyclones (TCs), which include typhoons/hurricanes and tropical storms, are examined using the latest 40-yr ECMWF Re-Analysis (ERA-40) dataset and Joint Typhoon Warning Center (JTWC) best-track data to ...

Jason E. Patla; Duane Stevens; Gary M. Barnes

2009-10-01T23:59:59.000Z

236

Improved representation of tropical Pacific ocean-atmosphere dynamics in an intermediate complexity climate model  

Science Conference Proceedings (OSTI)

A new anomaly coupling technique is introduced into a coarse-resolution dynamic climate model (LOVECLIM), improving the model’s representation of eastern equatorial Pacific surface temperature variability. The anomaly coupling amplifies the ...

Ryan L. Sriver; Axel Timmermann; Michael E. Mann; Klaus Keller; Hugues Goosse

237

The Sensitivity of the ECMWF Model to the Parameterization of Evaporation from the Tropical Oceans  

Science Conference Proceedings (OSTI)

Stimulated by the results of a simple SST anomaly experiment with the ECMWF forecast model, a study was carried out to examine the model parameterization of evaporation from the tropica] oceans. In earlier versions of the model, these fluxes were ...

M. J. Miller; A. C. M. Beljaars; T. N. Palmer

1992-05-01T23:59:59.000Z

238

Reactive transport in aquatic ecosystems: Rapid model prototyping in the open source software R  

Science Conference Proceedings (OSTI)

The concentrations of many natural compounds are altered by chemical and biological transformations, and physical processes such as adsorption and transport. Their fate can be predicted using reactive transport models that describe reaction and advective ... Keywords: Model, Open source, R, Reactive transport, Software

Karline Soetaert; Filip Meysman

2012-06-01T23:59:59.000Z

239

Accelerating agent-based ecosystem models using the cell broadband engine  

Science Conference Proceedings (OSTI)

This paper investigates how the parallel streaming capabilities of the Cell Broadband Engine can be used to speed up a class of agent-based plankton models generated from a domain-specific model compiler called the Virtual Ecology Workbench (VEW). We ...

Michael Lange; Tony Field

2010-06-01T23:59:59.000Z

240

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

SciTech Connect

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

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

2011-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical ecosystem model" 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

Sensitivity of Tropical Cyclone Rainbands to Ice-Phase Microphysics  

Science Conference Proceedings (OSTI)

A high-resolution tropical cyclone model with explicit cloud microphysics has been used to investigate the dynamics and energetics of tropical cyclone rainbands. As a first step, the model rainbands have been qualitatively compared with observed ...

Charmaine N. Franklin; Greg J. Holland; Peter T. May

2005-08-01T23:59:59.000Z

242

Dynamics and Thermodynamics of a Warming Event in a Coupled Tropical Atmosphere–Ocean Model  

Science Conference Proceedings (OSTI)

A simple coupled ocean–atmosphere model, similar to that of Zebiak and Cane, is used to examine the dynamic and thermodynamic processes associated with El Niño/Southern Oscillation (ENSO). The model is run for 300 years. The interannual ...

David S. Battisti

1988-10-01T23:59:59.000Z

243

Biases and Model Agreement in Projections of Climate Extremes over the Tropical Pacific  

Science Conference Proceedings (OSTI)

Using the Coupled Model Intercomparison Project phase 3 (CMIP3) general circulation models (GCMs), projections of a range of climate extremes are explored for the western Pacific. These projections include the 1-in-20-yr return levels and a ...

Sarah E. Perkins

2011-09-01T23:59:59.000Z

244

Experimental Tropical Cyclone Prediction Using the GFDL 25-km-Resolution Global Atmospheric Model  

Science Conference Proceedings (OSTI)

This paper describes a forecasting configuration of the Geophysical Fluid Dynamics Laboratory (GFDL) High-resolution Atmospheric Model (HiRAM). HiRAM represents an early attempt in unifying, within a global modeling framework, the capabilities of ...

Jeffrey S. Gall; Isaac Ginis; Shian-Jiann Lin; Timothy P. Marchok; Jan-Huey Chen

2011-12-01T23:59:59.000Z

245

Impacts of Land Surface Model Complexity on a Regional Simulation of a Tropical Synoptic Event  

Science Conference Proceedings (OSTI)

A multimode Chameleon Surface Model (CHASM) with different levels of complexity in parameterizing surface energy balance is coupled to a limited-area model (DARLAM) to investigate the impacts of complexity in land surface representations on the ...

H. Zhang; J. L. McGregor; A. Henderson-Sellers; J. J. Katzfey

2004-02-01T23:59:59.000Z

246

Models for the Prediction of Tropical Cyclone Motion over the North Atlantic: An Operational Evaluation  

Science Conference Proceedings (OSTI)

This study provides an operational evaluation of the seven prediction models-five statistical and two dynamical-used at the National Hurricane Center. Following a brief description of the rationale for each model, various performance ...

Charles J. Neumann; Joseph M. Pelissier

1981-03-01T23:59:59.000Z

247

Equilibrium Response and Transient Dynamics Datasets from VEMAP, the Vegetation/Ecosystem Modeling and Analysis Project  

DOE Data Explorer (OSTI)

Users of the VEMAP Portal can access input files of numerical data that include monthly and daily files of geographic data, soil and site files, scenario files, etc. Model results from Phase I, the Equilibrium Response datasets, are available through the NCAR anonymous FTP site at http://www.cgd.ucar.edu/vemap/vresults.html. Phase II, Transient Dynamics, include climate datasets, models results, and analysis tools. Many supplemental files are also available from the main data page at http://www.cgd.ucar.edu/vemap/datasets.html.

248

A p system based model of an ecosystem of some scavenger birds  

Science Conference Proceedings (OSTI)

In [1], we presented a P system in order to study the evolution of the bearded vulture in the Pyrenees (NE Spain). Here, we present a new model that overcomes some limitations of the previous work incorporating other scavenger species and additional ...

Mónica Cardona; M. Angels Colomer; Antoni Margalida; Ignacio Pérez-Hurtado; Mario J. Pérez-Jiménez; Delfí Sanuy

2009-08-01T23:59:59.000Z

249

Climate mitigation and the future of tropical landscapes  

Science Conference Proceedings (OSTI)

Land use change to meet 21st Century demands for food, fuel, and fiber will occur in the context of both a changing climate as well as societal efforts to mitigate climate change. This changing natural and human environment will have large consequences for forest resources, terrestrial carbon storage and emissions, and food and energy crop production over the next century. Any climate change mitigation policies enacted will change the environment under which land-use decisions are made and alter global land use change patterns. Here we use the GCAM integrated assessment model to explore how climate mitigation policies that achieve a climate stabilization at 4.5 W m-2 radiative forcing in 2100 and value carbon in terrestrial ecosystems interact with future agricultural productivity and food and energy demands to influence land use in the tropics. The regional land use results are downscaled from GCAM regions to produce gridded maps of tropical land use change. We find that tropical forests are preserved only in cases where a climate mitigation policy that values terrestrial carbon is in place, and crop productivity growth continues throughout the century. Crop productivity growth is also necessary to avoid large scale deforestation globally and enable the production of bioenergy crops. The terrestrial carbon pricing assumptions in GCAM are effective at avoiding deforestation even when cropland must expand to meet future food demand.

Thomson, Allison M.; Calvin, Katherine V.; Chini, Louise Parsons; Hurtt, George; Edmonds, James A.; Bond-Lamberty, Benjamin; Frolking, Steve; Wise, Marshall A.; Janetos, Anthony C.

2010-11-16T23:59:59.000Z

250

Microphysical and Radiative Effects of Ice Clouds on Tropical Equilibrium States: A Two-Dimensional Cloud-Resolving Modeling Study  

Science Conference Proceedings (OSTI)

The microphysical and radiative effects of ice clouds on tropical equilibrium states are investigated based on three two-dimensional cloud-resolving simulations imposed by zero vertical velocity and time-invariant zonal wind and sea surface ...

Fan Ping; Zhexian Luo; Xiaofan Li

2007-07-01T23:59:59.000Z

251

Impact of Increased TOVS Signal on the NMC Global Spectral Model: A Tropical-Plume Case Study  

Science Conference Proceedings (OSTI)

Information exists in tropical operational TIROS Operational Vertical Sounder (TOVS) radiance observations that is not utilized by operational sounding retrieval and analysis-initialization schemes. Temperature and moisture signals are extracted ...

James P. McGuirk

1993-03-01T23:59:59.000Z

252

Effects of Tropical Cyclones on Ocean Heat Transport in a High-Resolution Coupled General Circulation Model  

Science Conference Proceedings (OSTI)

In this paper the interplay between tropical cyclones (TCs) and the Northern Hemispheric ocean heat transport (OHT) is investigated. In particular, results from a numerical simulation of the twentieth-century and twenty-first-century climates, ...

Enrico Scoccimarro; Silvio Gualdi; Alessio Bellucci; Antonella Sanna; Pier Giuseppe Fogli; Elisa Manzini; Marcello Vichi; Paolo Oddo; Antonio Navarra

2011-08-01T23:59:59.000Z

253

Changes in Tropical Cyclone Activity due to Global Warming: Results from a High-Resolution Coupled General Circulation Model  

Science Conference Proceedings (OSTI)

This study investigates the possible changes that greenhouse global warming might generate in the characteristics of tropical cyclones (TCs). The analysis has been performed using scenario climate simulations carried out with a fully coupled high-...

S. Gualdi; E. Scoccimarro; A. Navarra

2008-10-01T23:59:59.000Z

254

The Impact of Gradient Wind Imbalance on Potential Intensity of Tropical Cyclones in an Unbalanced Slab Boundary Layer Model  

Science Conference Proceedings (OSTI)

The assumption of gradient wind balance is customarily made so as to derive the theoretical upper-bound intensity of a mature tropical cyclone. Emanuel's theory of hurricane potential intensity (E-PI) makes use of this assumption, whereas more ...

Thomas Frisius; Daria Schönemann; Jonathan Vigh

2013-07-01T23:59:59.000Z

255

The Role of Radiation in Influencing Tropical Cloud Distributions in a Radiative–Convective Equilibrium Cloud-Resolving Model  

Science Conference Proceedings (OSTI)

Observations by Johnson et al. depict regions of active tropical convection as possessing increased relative humidity through a deep layer and reduced low-level static stability when compared to nonconvecting regions. Shallow cumulus clouds, ...

Lyle Pakula; Graeme L. Stephens

2009-01-01T23:59:59.000Z

256

Extratropical Transition of Western North Pacific Tropical Cyclones: An Overview and Conceptual Model of the Transformation Stage  

Science Conference Proceedings (OSTI)

Extratropical transition (ET) in the western North Pacific is defined here in terms of two stages: transformation, in which the tropical cyclone evolves into a baroclinic storm; and reintensification, where the transformed storm then deepens as ...

Peter M. Klein; Patrick A. Harr; Russell L. Elsberry

2000-08-01T23:59:59.000Z

257

Predictors of Tropical Cyclone Numbers and Extreme Hurricane Intensities over the North Atlantic Using Generalized Additive and Linear Models  

Science Conference Proceedings (OSTI)

Fluctuations of the annual number of tropical cyclones over the North Atlantic and of the energy dissipated by the most intense hurricane of a season are related to a variety of predictors [global temperature, SST and detrended SST, North ...

Olivier Mestre; Stéphane Hallegatte

2009-02-01T23:59:59.000Z

258

Surface Flux Observations on the Southeastern Tropical Pacific Ocean and Attribution of SST Errors in Coupled Ocean–Atmosphere Models  

Science Conference Proceedings (OSTI)

A new dataset synthesizes in situ and remote sensing observations from research ships deployed to the southeastern tropical Pacific stratocumulus region for 7 years in boreal fall. Surface meteorology, turbulent and radiative fluxes, aerosols, ...

Simon P. de Szoeke; Christopher W. Fairall; Daniel E. Wolfe; Ludovic Bariteau; Paquita Zuidema

2010-08-01T23:59:59.000Z

259

NPP Tropical Forest: Chamela, Mexico  

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

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

260

A Spectral Cumulus Parameterization for Use in Numerical Models of the Tropical Atmosphere  

Science Conference Proceedings (OSTI)

The spectral cumulus parameterization theory of Arakawa and Schubert is presented in the convective flux form as opposed to the original detrainment form. This flux form is more convenient for use in numerical prediction models. The equations are ...

James J. Hack; Wayne H. Schubert; Pedro L. Silva Dias

1984-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical ecosystem model" 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

Eta Model Precipitation Forecasts for a Period Including Tropical Storm Allison  

Science Conference Proceedings (OSTI)

A step-mountain (eta) coordinate limited-area model is being developed at the National Meteorological Center (NMC) to improve forecasts of severe weather and other mesoscale phenomena. Precipitation forecasts are reviewed for the 20-day period 16 ...

Fedor Mesinger; Thomas L. Black; David W. Plummer; John H. Ward

1990-09-01T23:59:59.000Z

262

Role of a Parameterized Ice-Phase Microphysics in an Axisymmetric, Nonhydrostatic Tropical Cyclone Model  

Science Conference Proceedings (OSTI)

Results of an axisymmetric, nonhydrostatic hurricane model are analyzed with emphasis on the role of a parameterized ice-phase microphysics Inclusion of ice processes produces dramatic differences in the structure and evolution of the simulated ...

Stephen J. Lord; Hugh E. Willoughby; Jacqueline M. Piotrowicz

1984-10-01T23:59:59.000Z

263

Seasonal Heat Transport in a Primitive Equations Model of the Tropical Indian Ocean  

Science Conference Proceedings (OSTI)

This work analyses seasonal heat transport in an ocean-only numerical simulation of the Indian Ocean forced by realistic seasonal winds and surface heat fluxes north of 15°S, assuming no Indonesian Throughflow. The seasonal changes in the model ...

S. Wacongne; R. Pacanowski

1996-12-01T23:59:59.000Z

264

Climatic Effects on Lake Basins. Part I: Modeling Tropical Lake Levels  

Science Conference Proceedings (OSTI)

The availability of satellite estimates of rainfall and lake levels offers exciting new opportunities to estimate the hydrologic properties of lake systems. Combined with simple basin models, connections to climatic variations can then be explored ...

Martina Ricko; James A. Carton; Charon Birkett

2011-06-01T23:59:59.000Z

265

Surface Energy Fluxes and Coupled Variability in the Tropics of a Coupled General Circulation Model  

Science Conference Proceedings (OSTI)

The effect of wind-evaporative feedbacks upon ENSO, and the coupling of Pacific and Indian Ocean variability, is considered based upon a 110-yr simulation from a coupled ocean and atmosphere general circulation model.

R. L. Miller; X. Jiang

1996-07-01T23:59:59.000Z

266

Inversion Methods of Three Cumulus Parameterizations for Diabatic Initialization of a Tropical Cyclone Model  

Science Conference Proceedings (OSTI)

To generate convective precipitation consistent with observations at the beginning of a forecast with an atmospheric prediction model, the irrotational circulation and moisture fields must be initialized properly for dynamical balance with the ...

Akira Kasahara; Jun-Ichi Tsutsui; Hiromaru Hirakuchi

1996-10-01T23:59:59.000Z

267

Modeling of Tropical Forcing of Persistent Droughts and Pluvials over Western North America: 1856–2000  

Science Conference Proceedings (OSTI)

The causes of persistent droughts and wet periods, or pluvials, over western North America are examined in model simulations of the period from 1856 to 2000. The simulations used either (i) global sea surface temperature data as a lower boundary ...

Richard Seager; Yochanan Kushnir; Celine Herweijer; Naomi Naik; Jennifer Velez

2005-10-01T23:59:59.000Z

268

Comparison of Tropical Ocean–Atmosphere Fluxes with the NCAR Community Climate Model CCM3  

Science Conference Proceedings (OSTI)

The properties of the marine boundary layer produced by the National Center for Atmospheric Research (NCAR) Community Climate Model version 3 (CCM3) are compared with observations from two experiments in the central and western equatorial ...

William D. Collins; Junyi Wang; Jeffrey T. Kiehl; Guang J. Zhang; Daniel I. Cooper; William E. Eichinger

1997-12-01T23:59:59.000Z

269

Statistical Assessment of Tropical Convection-Permitting Model Simulations Using a Cell-Tracking Algorithm  

Science Conference Proceedings (OSTI)

This study presents a method for comparing convection-permitting model simulations to radar observations using an innovative object-based approach. The method uses the automated cell-tracking algorithm, Thunderstorm Identification Tracking ...

Simon Caine; Todd P. Lane; Peter T. May; Christian Jakob; Steven T. Siems; Michael J. Manton; James Pinto

2013-02-01T23:59:59.000Z

270

Hierarchical Tropical Cloud Systems in an Analog Shallow-Water Model  

Science Conference Proceedings (OSTI)

Recent observations have revealed an hierarchy of cloud clusters and superclusters within the Madden-Julian oscillation of the equatorial troposphere. The authors here report on the results of simulations with a model based on a simple nonlinear ...

Jun-Ichi Yano; James C. McWilliams; Mitchell W. Moncrieff; Kerry A. Emanuel

1995-05-01T23:59:59.000Z

271

The semi-automated classification of acoustic imagery for characterizing coral reef ecosystems  

Science Conference Proceedings (OSTI)

Coral reef habitat maps describe the spatial distribution and abundance of tropical marine resources, making them essential for ecosystem-based approaches to planning and management. Typically, these habitat maps have been created from optical and acoustic ...

B. M. Costa, T. A. Battista

2013-09-01T23:59:59.000Z

272

Terrestrial ecosystems and climatic change  

SciTech Connect

The structure and function of terrestrial ecosystems depend on climate, and in turn, ecosystems influence atmospheric composition and climate. A comprehensive, global model of terrestrial ecosystem dynamics is needed. A hierarchical approach appears advisable given currently available concepts, data, and formalisms. The organization of models can be based on the temporal scales involved. A rapidly responding model describes the processes associated with photosynthesis, including carbon, moisture, and heat exchange with the atmosphere. An intermediate model handles subannual variations that are closely associated with allocation and seasonal changes in productivity and decomposition. A slow response model describes plant growth and succession with associated element cycling over decades and centuries. These three levels of terrestrial models are linked through common specifications of environmental conditions and constrain each other. 58 refs.

Emanuel, W.R. (Oak Ridge National Lab., TN (USA)); Schimel, D.S. (Colorado State Univ., Fort Collins, CO (USA). Natural Resources Ecology Lab.)

1990-01-01T23:59:59.000Z

273

On the Origin of the Tropical Intraseasonal Oscillation  

Science Conference Proceedings (OSTI)

This study provides an explanation for the origin of the tropical intraseasonal (40–50 day) oscillation (TIO) based on a simple generalization of Gill's linear analytic model for tropical large-scale heat-induced circulation. The solution, which ...

Winston C. Chao

1987-08-01T23:59:59.000Z

274

An Alternative Tropical Cyclone Intensity Forecast Verification Technique  

Science Conference Proceedings (OSTI)

The National Hurricane Center (NHC) does not verify official or model forecasts if those forecasts call for a tropical cyclone to dissipate or if the real tropical cyclone dissipates. A new technique in which these forecasts are included in a ...

Sim D. Aberson

2008-12-01T23:59:59.000Z

275

Estimating Rainfall in the Tropics Using the Fractional Time Raining  

Science Conference Proceedings (OSTI)

The relationship between the fractional time raining and tropical rainfall amount is investigated using raingage data and a point process model of tropical rainfall. Both the strength and the nature of the relationship are dependent upon the ...

Mark L. Morrissey; Witold F. Krajewski; Michael J. McPhaden

1994-03-01T23:59:59.000Z

276

Innovation Ecosystem Development Initiative  

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

Trust Location: Chicago, IL Project Title Illinois Cleantech Ecosystem Consortium (ICE) Proposed Action or Project Description The Illinois Cleantech Ecosystem Consortium, a...

277

Sensitivity of terrestrial ecosystems to elevated atmospheric CO{sub 2}: Comparisons of model simulation studies to CO{sub 2} effect  

Science Conference Proceedings (OSTI)

In the context of a project to compare terrestrial ecosystem models, the Vegetation/Ecosystem Modeling and Analysis Project (VEMAP), we have analyzed how three biogeochemistry models link plant growth to doubled atmospheric CO{sub 2}. A common set of input data was used to drive three biogeochemistry models, BIOME-BGC, CENTURY and TEM. For the continental United States the simulation results show that with doubled CO{sub 2}, NPP increased by 8.7%, 5.0% and 10.8% for TEM, CENTURY and BIOME-BGC, respectively. At the biome level the range of NPP estimates varied considerably among models. TEM-simulated enhancement of NPP ranged from 2% to 28%; CENTURY, from 2% to 9%; and BIOME-BGC, from 4% to 27%. A transect analysis across several biomes along a latitude at 41.5 N shows that the TEM-simulated CO{sub 2} enhancement of NPP ranged from 0% to 22%; CENTURY, from 1% to 10% and BIOME-BGC, from 1% to 63%. In this study, we have investigated the underlying mechanisms of the three models to reveal how increased CO{sub 2} affects photosynthesis rate, water using efficiency and nutrient cycles. The relative importance of these mechanisms in each of the three biogeochemistry models will be discussed.

Pan, Y. [Marine Biological Lab., Woods Hole, MA (United States)

1995-06-01T23:59:59.000Z

278

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,

279

Future Change of North Atlantic Tropical Cyclone Tracks: Projection by a 20-km-Mesh Global Atmospheric Model  

Science Conference Proceedings (OSTI)

Possible future change in tropical cyclone (TC) activity over the North Atlantic (NA) was investigated by comparison of 25-yr simulations of the present-day climate and future change under the A1B emission scenario using a 20-km-mesh ...

Hiroyuki Murakami; Bin Wang

2010-05-01T23:59:59.000Z

280

THE WORLD RECORD STORM SURGE AND THE MOST INTENSE SOUTHERN HEMISPHERE TROPICAL CYCLONE – NEW EVIDENCE AND MODELING  

Science Conference Proceedings (OSTI)

The world record for a storm surge is 13 m occurring during landfall of Tropical Cyclone Mahina in northeast Australia, March 1899. The central pressure of this cyclone has been reported as 914 hPa as measured by ships barometer during passage of the eye. ...

JONATHAN NOTT; CAMILLA GREEN; IAN TOWNSEND; JEFFREY CALLAGHAN

Note: This page contains sample records for the topic "tropical ecosystem model" 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

MJO and Tropical Cyclogenesis in the Gulf of Mexico and Eastern Pacific: Case Study and Idealized Numerical Modeling  

Science Conference Proceedings (OSTI)

The role of the Madden–Julian oscillation (MJO) in modulating the frequency and location of tropical cyclogenesis over the eastern Pacific and the Gulf of Mexico during August–September 1998 is examined. During the nonconvective phase of the MJO, ...

Anantha Aiyyer; John Molinari

2008-08-01T23:59:59.000Z

282

Environmental Control of Tropical Cyclone Intensity  

Science Conference Proceedings (OSTI)

The influence of various environmental factors on tropical cyclone intensity is explored using a simple coupled ocean–atmosphere model. It is first demonstrated that this model is capable of accurately replicating the intensity evolution of ...

Kerry Emanuel; Christopher DesAutels; Christopher Holloway; Robert Korty

2004-04-01T23:59:59.000Z

283

Tropical cyclones and climate change review article  

E-Print Network (OSTI)

Whether the characteristics of tropical cyclones have changed or will change in a warming climate — and if so, how — has been the subject of considerable investigation, often with conflicting results. Large amplitude fluctuations in the frequency and intensity of tropical cyclones greatly complicate both the detection of long-term trends and their attribution to rising levels of atmospheric greenhouse gases. Trend detection is further impeded by substantial limitations in the availability and quality of global historical records of tropical cyclones. Therefore, it remains uncertain whether past changes in tropical cyclone activity have exceeded the variability expected from natural causes. However, future projections based on theory and high-resolution dynamical models consistently indicate that greenhouse warming will cause the globally averaged intensity of tropical cyclones to shift towards stronger storms, with intensity increases of 2–11 % by 2100. Existing modelling studies also consistently project decreases in the globally averaged frequency of tropical cyclones, by 6–34%. Balanced against this, higher resolution modelling studies typically project substantial increases in the frequency of the most intense cyclones, and increases of the order of 20% in the precipitation rate within 100 km of the storm centre. For all cyclone parameters, projected changes for individual basins show large variations between different modelling studies. The challenge for climate change detection and attribution research with regard to tropical cyclones is to determine whether an observed change in tropical cyclone activity

Thomas R. Knutson; John L. Mcbride; Johnny Chan; Kerry Emanuel; Greg Holl; Chris L; Isaac Held; James P. Kossin; A. K. Srivastava; Masato Sugi

2010-01-01T23:59:59.000Z

284

Atlantic Tropical Systems of 1988  

Science Conference Proceedings (OSTI)

.The 1988 season produced 62 tropical waves, 19 tropical depressions and 12 tropical storms, 5 of which became hurricanes. Eighty-three percent of the tropical storms developed from African waves. A comparison with the past 21 years is included.

Lixion A. Avila; Gilbert B. Clark

1989-10-01T23:59:59.000Z

285

The Role of Clouds, Water Vapor, Circulation, and Boundary Layer Structure in the Sensitivity of the Tropical Climate  

Science Conference Proceedings (OSTI)

The physical mechanisms that affect the tropical sea surface temperature (SST) are investigated using a two-box equilibrium model of the Tropics. One box represents the convecting, warm SST, high humidity region of the Tropics, and the other box ...

Kristin Larson; Dennis L. Hartmann; Stephen A. Klein

1999-08-01T23:59:59.000Z

286

Comparing Tropical Forest Projections from Two Generations of Hadley Centre Earth System Models, HadGEM2-ES and HadCM3LC  

Science Conference Proceedings (OSTI)

Future changes in atmospheric greenhouse gas concentrations and associated influences on climate could affect the future sustainability of tropical forests. The authors report on tropical forest projections from the new Hadley Centre Global ...

Peter Good; Chris Jones; Jason Lowe; Richard Betts; Nicola Gedney

2013-01-01T23:59:59.000Z

287

A REVISED CONCEPTUAL MODEL OF THE TROPICAL MARINE BOUNDARY LAYER. PART I: STATISTICAL CHARACTERIZATION OF THE VARIABILITY INHERENT IN THE WINTERTIME TRADE WIND REGIME OVER THE WESTERN TROPICAL ATLANTIC  

Science Conference Proceedings (OSTI)

This paper investigates wintertime tropical marine boundary layer (TMBL) statistical characteristics over the western North Atlantic using the complete set of island-launched soundings from the Rain in Cumulus over the Ocean (RICO) Experiment. The ...

Jennifer L. Davison; Robert M. Rauber; Larry Di Girolamo; Margaret A. LeMone

288

A Revised Conceptual Model of the Tropical Marine Boundary Layer. Part I: Statistical Characterization of the Variability Inherent in the Wintertime Trade Wind Regime over the Western Tropical Atlantic  

Science Conference Proceedings (OSTI)

This paper investigates wintertime tropical marine boundary layer (TMBL) statistical characteristics over the western North Atlantic using the complete set of island-launched soundings from the Rain in Cumulus over the Ocean (RICO) experiment. The ...

Jennifer L. Davison; Robert M. Rauber; Larry Di Girolamo; Margaret A. LeMone

2013-10-01T23:59:59.000Z

289

Maintenance of Tropical Intraseasonal Variability: Impact of Evaporation–Wind Feedback and Midlatitude Storms  

Science Conference Proceedings (OSTI)

An intraseasonal tropical oscillation with a period of 20–80 days is simulated in the Neelin–Zeng Quasi-Equilibrium Tropical Circulation Model. This model is an intermediate-level atmospheric model that includes primitive equation nonlinearity, ...

Johnny Wei-Bing Lin; J. David Neelin; Ning Zeng

2000-09-01T23:59:59.000Z

290

Baroclinically Induced Tropical Cyclogenesis  

Science Conference Proceedings (OSTI)

The authors investigate the transition of numerous subtropical cyclones into late season tropical storms and hurricanes during the 2000 and 2001 Atlantic tropical cyclone seasons. In all transitioning cases (10), the 900–200-hPa wind shear was ...

Christopher A. Davis; Lance F. Bosart

2003-11-01T23:59:59.000Z

291

EMSL: Science: Terrestrial & Subsurface Ecosystems  

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

Terrestrial & Subsurface Ecosystems Terrestrial & Subsurface Ecosystems Terrestrial and Subsurface Ecosystems logo Visualization of CFD-simulated fluid velocities within a single pore space between randomly packed spherical grains Visualization of CFD-simulated fluid velocities within a single pore space between randomly packed spherical grains. The Terrestrial and Subsurface Ecosystems Science Theme focuses on the dynamics of nutrients, metabolites, and contaminants at biogeochemical interfaces in heterogeneous environments across multiple scales. By providing a mechanistic understanding of biogeochemical and microbial processes in soils and the subsurface, and linking those processes via pore-scale hydrological models, EMSL can improve strategies for sustainable solutions to contaminant attenuation, remediation and biogeochemical

292

Tropical Atlantic Biases in CCSM4  

Science Conference Proceedings (OSTI)

This paper focuses on diagnosing biases in the seasonal climate of the tropical Atlantic in the twentieth-century simulation of the Community Climate System Model, version 4 (CCSM4). The biases appear in both atmospheric and oceanic components. ...

Semyon A. Grodsky; James A. Carton; Sumant Nigam; Yuko M. Okumura

2012-06-01T23:59:59.000Z

293

A Numerical Investigation of Tropical Island Thunderstorms  

Science Conference Proceedings (OSTI)

A version of the United Kingdom Meteorological Office mesoscale weather prediction model is used to simulate cases of deep tropical convection from the Island Thunderstorm Experiment off the north coast of Australia. Selected cases contrast ...

B. W. Golding

1993-05-01T23:59:59.000Z

294

Momentum Transports Associated with Tropical Cyclone Recurvature  

Science Conference Proceedings (OSTI)

This study attempts to investigate the linear momentum budget responsible for tropical cyclone (TC) recurvature. Using the operational analyses from the U.K. Meteorological Office global model, the environmental flow associated with recurving TCs ...

Y. S. Li; Johnny C. L. Chan

1999-06-01T23:59:59.000Z

295

The IC Brazil ecosystem  

Science Conference Proceedings (OSTI)

Brazilian Government has done a strong effort to develop the Microelectronics area in Brazil. An ecosystem of communities interested to rethink the insertion of Brazil in the important market of semiconductors. Important questions should be considered ... Keywords: IC projects, IT ecosystems and e-government, collaborative ecosystems, education, semiconductors

Oscar S. Silva Filho

2013-10-01T23:59:59.000Z

296

Temporal variation in stable isotopic composition of rainfall and groundwater in a tropical dry forest in the northeastern Caribbean  

Science Conference Proceedings (OSTI)

Karst topography links rainfall to groundwater recharge, therefore possible changes in the hydrology can play an important role in ecosystem function especially in tropical dry forests where water is the most limiting resource. This study ...

Y. Govender; E. Cuevas; L. D. S. Sternberg; M. R. Jury

297

Metric Selection for Ecosystem Restoration  

E-Print Network (OSTI)

managers identify the best metrics to evaluate and select the recommended restoration plan, monitor and assess progress toward achieving project objectives, and, if necessary, inform adaptive management decisions. Performance metrics, or measurable system components used to estimate and track the state of critical aspects of the project, are often the basis for project decision making and furthering scientific understanding. As such, ecosystem restoration planners should take time to carefully select an appropriate and effective metric set. To help planners with this task, this technical note accomplishes the following: 1. Reviews current USACE ecosystem restoration planning and monitoring policy, regulations and guidelines. 2. Explains the importance of metric selection and its roles during planning and post-construction monitoring and assessment. 3. Reviews common options for identifying and selecting metrics including conceptual modeling, historical precedence, and best professional judgment. 4. Presents two metric evaluation methods, screening and multi-criteria decision analysis. 5. Discusses metric application to ecosystem restoration project planning and monitoring.

Matteo Convertino; Kelsie Baker; Connie Lu; John T. Vogel; Kyle Mckay; Igor Linkov

2013-01-01T23:59:59.000Z

298

Tropical anvil cirrus evolution from observations and numerical...  

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

cirrus evolution from observations and numerical simulations Deng, Min University of Utah Mace, Gerald University of Utah Category: Modeling The tropical anvil cirrus formation...

299

Radiative Forcing of a Tropical Direct Circulation by Soil Dust Aerosols  

Science Conference Proceedings (OSTI)

The effect of soil dust aerosols upon the tropical climate is estimated by forcing a simple model of a tropical direct circulation. The model consists of a region vertically mixed by deep convection and a nonconvecting region, for which budgets ...

R. L. Miller; I. Tegen

1999-07-01T23:59:59.000Z

300

Numerical Investigations on the Formation of Tropical Storm Debby during NAMMA-06  

Science Conference Proceedings (OSTI)

Mesoscale model forecasts were carried out beginning at 0000 UTC 19 August for simulating Tropical Disturbance 4, which was named Tropical Storm Debby on 22 August 2006. The Weather Research and Forecasting model, with 25-km grid spacing and an ...

Sen Chiao; Gregory S. Jenkins

2010-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical ecosystem model" 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

NPP and Driver Data for Ecosystem  

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

EMDI Data Revised Data Set: NPP Multi-Biome: NPP and Driver Data for Ecosystem Model-Data Intercomparison Effective Date of Revision: June 17, 2004 Data Set Citation: Olson, R. J.,...

302

Seasonal tropical cyclone forecasts  

E-Print Network (OSTI)

Seasonal forecasts of tropical cyclone activity in various regions have been developed since the first attempts in the early 1980s by Neville

Suzana J. Camargo; Anthony G. Barnston; Philip J. Klotzbach; Christopher W. Landsea

2007-01-01T23:59:59.000Z

303

The residual mean circulation in the tropical tropopause layer driven by tropical waves  

Science Conference Proceedings (OSTI)

We use latent heating estimates derived from rainfall observations to construct model experiments that isolate equatorial waves forced by tropical convection from mid-latitude synoptic-scale waves. These experiments are used to demonstrate that ...

David A. Ortland; M. Joan Alexander

304

Dynamical Tropical Cyclone Track Forecast Errors. Part I: Tropical Region Error Sources  

Science Conference Proceedings (OSTI)

All highly erroneous (>300 n mi or 555 km at 72 h) Navy Operational Global Atmospheric Prediction System (NOGAPS) and U.S. Navy version of the Geophysical Fluid Dynamics Laboratory model (GFDN) tropical cyclone track forecasts in the western ...

Lester E. Carr III; Russell L. Elsberry

2000-12-01T23:59:59.000Z

305

Cloud-Resolving Modeling of Tropical Cloud Systems during Phase III of GATE. Part I: Two-Dimensional Experiments  

Science Conference Proceedings (OSTI)

A formal framework is established for the way in which cloud-resolving numerical models are used to investigate the role of precipitating cloud systems in climate and weather forecasting models. Emphasis is on models with periodic lateral ...

Wojciech W. Grabowski; Xiaoqing Wu; Mitchell W. Moncrieff

1996-12-01T23:59:59.000Z

306

An integrated multi-criteria scenario evaluation web tool for participatory land-use planning in urbanized areas: The Ecosystem Portfolio Model  

Science Conference Proceedings (OSTI)

Land-use land-cover change is one of the most important and direct drivers of changes in ecosystem functions and services. Given the complexity of the decision-making, there is a need for Internet-based decision support systems with scenario evaluation ... Keywords: Decision support, Ecological value, Ecosystem restoration, Land-use planning, Quality of life, Sea level rise mitigation, Sustainability

W. B. Labiosa; W. M. Forney; A. -M. Esnard; D. Mitsova-Boneva; R. Bernknopf; P. Hearn; D. Hogan; L. Pearlstine; D. Strong; H. Gladwin; E. Swain

2013-03-01T23:59:59.000Z

307

Graduate studies Ecosystem Science  

E-Print Network (OSTI)

Graduate studies in Ecosystem Science and Management Ph.D. M.S. M.Agr. or Natural Resources Development MNRD Department of Ecosystem Science and Management College of Agriculture and Life Sciences. The thesisbased Master of Science and Ph.D. degrees are designed for research or academic careers

308

Effects of land markets and land management on ecosystem function: A framework for modelling exurban land-change  

Science Conference Proceedings (OSTI)

This paper presents the conceptual design and application of a new land-change modelling framework that represents geographical, sociological, economic, and ecological aspects of a land system. The framework provides an overarching design that can be ... Keywords: Agent-based modelling, Carbon storage and flux, Exurban development, Land-use and land-cover change, Policy

Derek T. Robinson, Shipeng Sun, Meghan Hutchins, Rick L. Riolo, Daniel G. Brown, Dawn C. Parker, Tatiana Filatova, William S. Currie, Sarah Kiger

2013-07-01T23:59:59.000Z

309

Estimating Seasonal Changes in Volumetric Soil Water Content at Landscape Scales in a Savanna Ecosystem Using Two-Dimensional Resistivity Profiling  

Science Conference Proceedings (OSTI)

Water distributed in deep soil reservoirs is an important factor determining the ecosystem structure of water-limited environments, such as the seasonal tropical savannas of South America. In this study a two-dimensional (2D) geoelectrical ...

Diana C. Garcia-Montiel; Michael T. Coe; Meyr P. Cruz; Joice N. Ferreira; Euzebio M. da Silva; Eric A. Davidson

2008-03-01T23:59:59.000Z

310

Formation and Quasi-Periodic Behavior of Outer Spiral Rainbands in a Numerically Simulated Tropical Cyclone  

Science Conference Proceedings (OSTI)

The formation and quasi-periodic behavior of outer spiral rainbands in a tropical cyclone simulated in the cloud-resolving tropical cyclone model version 4 (TCM4) are analyzed. The outer spiral rainbands in the simulation are preferably initiated ...

Qingqing Li; Yuqing Wang

2012-03-01T23:59:59.000Z

311

Multimodel Analysis of the Water Vapor Feedback in the Tropical Upper Troposphere  

Science Conference Proceedings (OSTI)

Relationships between the mean humidity in the tropical upper troposphere and tropical sea surface temperatures in 17 coupled ocean–atmosphere global climate models were investigated. This analysis builds on a prior study of humidity and surface ...

Ken Minschwaner; Andrew E. Dessler; Parnchai Sawaengphokhai

2006-10-01T23:59:59.000Z

312

The Role of Longwave Radiation and Boundary Layer Thermodynamics in Forcing Tropical Surface Winds  

Science Conference Proceedings (OSTI)

This paper reveals major deficiencies of the existing intermediate climate models for tropical surface winds and elaborates the important roles of cloud-longwave radiational forcing and boundary layer thermodynamics in driving the tropical ...

Xiouhua Fu; Bin Wang

1999-04-01T23:59:59.000Z

313

Rethinking Tropical Ocean Response to Global Warming: The Enhanced Equatorial Warming  

Science Conference Proceedings (OSTI)

The response of tropical Pacific SST to increased atmospheric CO2 concentration is reexamined with a new focus on the latitudinal SST gradient. Available evidence, mainly from climate models, suggests that an important tropical SST fingerprint to ...

Zhengyu Liu; Steve Vavrus; Feng He; Na Wen; Yafang Zhong

2005-11-01T23:59:59.000Z

314

The Impact of Ice Phase Cloud Parameterizations on Tropical Cyclone Prediction  

Science Conference Proceedings (OSTI)

The impact of ice phase cloud microphysical processes on prediction of tropical cyclone environment is examined for two microphysical parameterizations using the Coupled Ocean / Atmosphere Mesoscale Prediction System –Tropical Cyclone model. An ...

Yi Jin; Shouping Wang; Jason Nachamkin; James D. Doyle; Gregory Thompson; Louis Grasso; Teddy Holt; Jon Moskaitis; Hao Jin; Richard M. Hodur; Qingyun Zhao; Ming Liu; Mark DeMaria

315

Northwestward-Propagating Wave Patterns over the Tropical Western North Pacific during Summer  

Science Conference Proceedings (OSTI)

The possible relationship between northwestward-propagating wave disturbances and tropical cyclones over the tropical western North Pacific during summer is studied using data assimilated by the navy's global model during May–September 1989–91. A ...

C-P. Chang; J. M. Chen; P. A. Harr; L. E. Carr

1996-10-01T23:59:59.000Z

316

How Do Outer Spiral Rainbands Affect Tropical Cyclone Structure and Intensity?  

Science Conference Proceedings (OSTI)

A long-standing issue on how outer spiral rainbands affect the structure and intensity of tropical cyclones is studied through a series of numerical experiments using the cloud-resolving tropical cyclone model TCM4. Because diabatic heating due ...

Yuqing Wang

2009-05-01T23:59:59.000Z

317

Beta Test of the Systematic Approach Expert System Prototype as a Tropical Cyclone Track Forecasting Aid  

Science Conference Proceedings (OSTI)

The authors have developed error mechanism conceptual models with characteristic track departures and anomalous wind or sea level pressure patterns for dynamical tropical cyclone track predictions primarily occurring in tropical regions or those ...

Lester E. Carr III; Russell L. Elsberry; James E. Peak

2001-06-01T23:59:59.000Z

318

Regional Tropical Precipitation Change Mechanisms in ECHAM4/OPYC3 under Global Warming  

Science Conference Proceedings (OSTI)

Mechanisms of global warming impacts on regional tropical precipitation are examined in a coupled atmosphere–ocean general circulation model (ECHAM4/OPYC3). The pattern of the regional tropical precipitation changes, once established, tends to ...

Chia Chou; J. David Neelin; Jien-Yi Tu; Cheng-Ta Chen

2006-09-01T23:59:59.000Z

319

Local and Remote Impacts of Aerosol Climate Forcing on Tropical Precipitation  

Science Conference Proceedings (OSTI)

Mechanisms that determine the direct and indirect effects of aerosols on the tropical climate involve moist dynamical processes and have local and remote impacts on regional tropical precipitation. These mechanisms are examined in a climate model ...

Chia Chou; J. David Neelin; Ulrike Lohmann; Johann Feichter

2005-11-01T23:59:59.000Z

320

How Does the Boundary Layer Contribute to Eyewall Replacement Cycles in Axisymmetric Tropical Cyclones?  

Science Conference Proceedings (OSTI)

Three diagnostic models of the axisymmetric tropical cyclone boundary layer, with different levels of approximation, are applied to the problem of tropical cyclones with concentric eyewalls. The outer eyewall is shown to have an inherently ...

Jeffrey D. Kepert

2013-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical ecosystem model" 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

How does the boundary layer contribute to eyewall replacement cycles in axisymmetric tropical cyclones?  

Science Conference Proceedings (OSTI)

Three diagnostic models of the axisymmetric tropical cyclone boundary layer, with different levels of approximation, are applied to the problem of tropical cyclones with concentric eyewalls. The outer eyewall is shown to have an inherently ...

Jeffrey D. Kepert

322

Impact Assessment of Simulated Doppler Wind Lidars with a Multivariate Variational Assimilation in the Tropics  

Science Conference Proceedings (OSTI)

This paper deals with the dynamical aspect of variational data assimilation in the tropics and the role of the background-error covariances in the observing system simulation experiments for the tropics. The study uses a model that describes the ...

Nedjeljka Žagar; Ad Stoffelen; Gert-Jan Marseille; Christophe Accadia; Peter Schlüssel

2008-07-01T23:59:59.000Z

323

Extratropical summertime response to tropical interannual variability in an idealized GCM  

Science Conference Proceedings (OSTI)

A primitive equation model is used to investigate the role of the tropics in generating seasonal mean anomalies in the extratropics. A nudging technique is applied to guide selected tropical regions towards ERA40 and NCEP2 reanalyses. The time-...

Nicholas M. J. Hall; Hervé Douville; Laurent Li

324

Simulation of the Tropical Pacific Climate with a Coupled Ocean-Atmosphere General Circulation Model. Part II: Interannual Variability  

Science Conference Proceedings (OSTI)

Two multiyear simulations with a coupled ocean-atmosphere general circulation model (GCM)-totaling 45 years-are used to investigate interannual variability at the equator. The model consists of the UCLA global atmospheric GCM coupled to the GFDL ...

A. W. Robertson; C-C. Ma; M. Ghil; C. R. Mechoso

1995-05-01T23:59:59.000Z

325

A Coupled Atmosphere–Wave–Ocean Modeling System: Simulation of the Intensity of an Idealized Tropical Cyclone  

Science Conference Proceedings (OSTI)

A coupled atmosphere–wave–ocean modeling system (CAWOMS) based on the integration of atmosphere–wave, atmosphere–ocean, and wave–current interaction processes is developed. The component models consist of the Weather Research and Forecasting (WRF)...

Bin Liu; Huiqing Liu; Lian Xie; Changlong Guan; Dongliang Zhao

2011-01-01T23:59:59.000Z

326

Variability of the Tropical Atlantic Ocean Simulated by a General Circulation Model with Two Different Mixed-Layer Physics  

Science Conference Proceedings (OSTI)

The embedment of a 1.5 turbulence closure model in an ocean general circulation model of the equatorial Atlantic is presented. The eddy viscosity and diffusivity involved in the vertical mixing are defined as the product of a characteristic ...

Bruno Blanke; Pascale Delecluse

1993-07-01T23:59:59.000Z

327

Simulation of the Tropical Oceans with an Ocean GCM Coupled to an Atmospheric Mixed-Layer Model  

Science Conference Proceedings (OSTI)

A reduced gravity, primitive equation, ocean general circulation model (GCM) is coupled to an advective atmospheric mixed-layer (AML) model to demonstrate the importance of a nonlocal atmospheric mixed-layer parameterization for a proper ...

Ragu Murtugudde; Richard Seager; Antonio Busalacchi

1996-08-01T23:59:59.000Z

328

Convective Entrainment and Large-Scale Organization of Tropical Precipitation: Sensitivity of the CNRM-CM5 Hierarchy of Models  

Science Conference Proceedings (OSTI)

The spurious double intertropical convergence zone (ITCZ) is a systematic bias affecting state-of-the-art coupled general circulation models (GCMs). Modeling studies show that the ITCZ structure is very sensitive to moist convection ...

Boutheina Oueslati; Gilles Bellon

2013-05-01T23:59:59.000Z

329

Soil community composition and ecosystem processes Comparing agricultural ecosystems with natural ecosystems  

E-Print Network (OSTI)

Soil community composition and ecosystem processes Comparing agricultural ecosystems with natural, nitrogen, pesticides Abstract. Soil organisms play principal roles in several ecosystem functions, i decomposition, and acting as an environmental buffer. Agricultural soils would more closely resemble soils

Neher, Deborah A.

330

Latent Heating and Cooling Rates in Developing and Nondeveloping Tropical Disturbances during TCS-08: Radar-Equivalent Retrievals from Mesoscale Numerical Models and ELDORA  

Science Conference Proceedings (OSTI)

Latent heating and cooling rates have a critical role in predicting tropical cyclone formation and intensification. In a prior study, Park and Elsberry estimated the latent heating and cooling rates from aircraft Doppler radar [Electra Doppler ...

Myung-Sook Park; Andrew B. Penny; Russell L. Elsberry; Brian J. Billings; James D. Doyle

2013-01-01T23:59:59.000Z

331

Factors Maintaining the Zonally Asymmetric Precipitation Distribution and Low-Level Flow in the Tropics of an Atmospheric General Circulation Model: Diagnostic Studies  

Science Conference Proceedings (OSTI)

The roles played by the large-scale motion induced by vertical diffusion of heat from the lower boundary and condensational heating due to deep convection in maintaining the precipitation zones in the Tropics of an atmospheric general circulation ...

David G. Dewitt; Edwin K. Schneider; Anandu D. Vernekar

1996-08-01T23:59:59.000Z

332

Simulation of ENSO-Related Surface Winds in the Tropical Pacific by an Atmospheric General Circulation Model Forced by Observed Sea Surface Temperatures  

Science Conference Proceedings (OSTI)

The authors present the simulation of the tropical Pacific surface wind variability by a low-resolution (R15 horizontal resolution and 18 vertical levels) version of the Center for Ocean-Land-Atmosphere Interactions, Maryland, general circulation ...

B. N. Goswami; V. Krishnamurthy; N. H. Saji

1995-06-01T23:59:59.000Z

333

The Tropical Eastern Pacific Seasonal Cycle: Assessment of Errors and Mechanisms in IPCC AR4 Coupled Ocean–Atmosphere General Circulation Models  

Science Conference Proceedings (OSTI)

Warmer SST and more rain in the Northern Hemisphere are observed year-round in the tropical eastern Pacific with southerly wind crossing the equator toward the atmospheric heating. The southerlies are minimal during boreal spring, when two ...

Simon P. de Szoeke; Shang-Ping Xie

2008-06-01T23:59:59.000Z

334

Trends Online - Ecosystems  

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

Ecosystems Area and Carbon Content of Sphagnum Since Last Glacial Maximum - K. Gajewski, A. Viau, M. Sawada, D. Atkinson and S. Wilson Studies of present and past conditions are...

335

ecosystem in South Africa  

E-Print Network (OSTI)

Abstract. The principal mechanisms that connect carbon fluxes with water relations in savanna ecosystems were studied by using eddy covariance method in a savanna ecosystem at Kruger National Park, South Africa. Since the annual drought and rewetting cycle is a major factor influencing the function of savanna ecosystems, this work focused on the close inter-connection between water relations and carbon fluxes. Data from a nine-month measuring campaign lasting from the early wet season to the late dry season were used. Total ecosystem respiration showed highest values at the onset of the growing season, a slightly lower plateau during the main part of the growing season and a continuous decrease during the transition towards the dry season. The regulation of canopy conductance was changed in two ways: changes due to phenology during the course of the

W. L. Kutsch; N. Hanan; B. Scholes; I. Mchugh; W. Kubheka; H. Eckhardt; C. Williams

2008-01-01T23:59:59.000Z

336

Clouds in Tropical Cyclones  

Science Conference Proceedings (OSTI)

Clouds within the inner regions of tropical cyclones are unlike those anywhere else in the atmosphere. Convective clouds contributing to cyclogenesis have rotational and deep intense updrafts but tend to have relatively weak downdrafts. Within ...

Robert A. Houze Jr.

2010-02-01T23:59:59.000Z

337

Clouds in Tropical Cyclones  

Science Conference Proceedings (OSTI)

Clouds within the inner regions of tropical cyclones are unlike those anywhere else in the atmosphere. Convective clouds contributing to cyclogenesis have rotational and deep intense updrafts but tend to have relatively weak downdrafts. Within the ...

Robert A. Houze Jr.

2010-02-01T23:59:59.000Z

338

Weak Simulated Extratropical Responses to Complete Tropical Deforestation  

Science Conference Proceedings (OSTI)

The Geophysical Fluid Dynamics Laboratory atmosphere–land model version 2 (AM2/LM2) coupled to a 50-m-thick slab ocean model has been used to investigate remote responses to tropical deforestation. Magnitudes and significance of differences ...

Kirsten L. Findell; Thomas R. Knutson; P. C. D. Milly

2006-06-01T23:59:59.000Z

339

Control of the Tropical Tropopause and Vertical Transport across It  

Science Conference Proceedings (OSTI)

A 3D primitive equation model is used to investigate how the tropical tropopause is influenced by cumulus convection in the troposphere and mean upwelling in the stratosphere. The model simulates the residual mean circulation explicitly, whereas ...

Murry Salby; Patrick Callaghan

2004-03-01T23:59:59.000Z

340

Mechanisms of Remote Tropical Surface Warming during El Niño  

Science Conference Proceedings (OSTI)

The authors demonstrate through atmospheric general circulation model (the Community Climate Model version 3.10) simulations of the 1997/98 El Niño that the observed “remote” (i.e., outside the Pacific) tropical land and ocean surface warming ...

John C. H. Chiang; Benjamin R. Lintner

2005-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical ecosystem model" 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

Ocean Dynamics, Thermocline Adjustment, and Regulation of Tropical SST  

Science Conference Proceedings (OSTI)

The role of tropical Pacific ocean dynamics in regulating the ocean response to thermodynamic forcing is investigated using an ocean general circulation model (GCM) coupled to a model of the atmospheric mixed layer. It is found that the basin ...

Richard Seager; Ragu Murtugudde

1997-03-01T23:59:59.000Z

342

Tropical Storm Development and Decay: Sensitivity to Surface Boundary Conditions  

Science Conference Proceedings (OSTI)

Hurricane models have rarely been used to investigate the observational fact that tropical disturbances seldom form, develop, or intensify over land. Furthermore, rather ad hoc assumptions have been made when modeling landfall. The general ...

Robert E. Tuleya

1994-02-01T23:59:59.000Z

343

The Influence of Solar Forcing on Tropical Circulation  

Science Conference Proceedings (OSTI)

The response of the seasonal tropical circulation to an 11-yr solar cycle forcing is studied with the Goddard Institute for Space Studies (GISS) ModelE, which includes fully interactive atmospheric chemistry. To identify characteristic solar ...

Jae N. Lee; Drew T. Shindell; Sultan Hameed

2009-11-01T23:59:59.000Z

344

Sensitivity of Tropical Cyclone Forecasts as Revealed by Singular Vectors  

Science Conference Proceedings (OSTI)

Singular vector (SV) sensitivity, calculated using the adjoint model of the U.S. Navy Operation Global Atmosphere Prediction System (NOGAPS), is used to study the dynamics associated with tropical cyclone evolution. For each model-predicted ...

Melinda S. Peng; Carolyn A. Reynolds

2006-10-01T23:59:59.000Z

345

Improving Tropical Cyclone Intensity Guidance in the Eastern North Pacific  

Science Conference Proceedings (OSTI)

The primary objective of this research is the development of a statistical model that will provide tropical cyclone (TC) intensity guidance for the eastern North Pacific (ENP) superior to that provided by climatology and persistence models. ...

Kevin R. Petty; Jay S. Hobgood

2000-04-01T23:59:59.000Z

346

The Finite-Amplitude Nature of Tropical Cyclogenesis  

Science Conference Proceedings (OSTI)

We have constructed a simple, balanced, axisymmetric model as a means of understanding the existence of the threshold amplitude for tropical cyclogenesis discovered by Rotunno and Emanuel. The model is similar to Ooyama's but is phrased in ...

Kerry A. Emanuel

1989-11-01T23:59:59.000Z

347

Universality of the Modeled Small-Scale Response of the Upper Tropical Ocean to Squall Wind Forcing  

Science Conference Proceedings (OSTI)

The upper ocean response to idealized surface wind forcing that is representative of conditions observed during the TOGA-COARE Intensive Observation Period is studied by numerical simulations using a second-moment closure model. A set of ...

R. A. Richardson; G. G. Sutyrin; D. Hebert; L. M. Rothstein

1999-03-01T23:59:59.000Z

348

Toward an understanding of vertical momentum transports in cloud system resolving model simulations of multiscale tropical convection  

Science Conference Proceedings (OSTI)

This study examines the characteristics of convective momentum transport (CMT) and gravity wave momentum transport (GWMT) in two-dimensional cloud-system resolving model simulations, including the relationships between the two transports. A linear ...

Tiffany A. Shaw; Todd P. Lane

349

Initialization of a Cloud-Resolving Model with Airborne Doppler Radar Observations of an Oceanic Tropical Convective System  

Science Conference Proceedings (OSTI)

Doppler radar–derived fields of wind and reflectivity, retrieved temperature perturbations, estimated water vapor, and cloud water contents are used to initialize a nonhydrostatic cloud-resolving model. Airborne Doppler data collected in a ...

Soline Bielli; Frank Roux

1999-06-01T23:59:59.000Z

350

Principal Modes of Atmospheric Variability in Model Atmospheres with and without Anomalous Sea Surface Temperature Forcing in the Tropical Pacific  

Science Conference Proceedings (OSTI)

Principal modes of low-frequency atmospheric variability and the influence of sea surface temperature anomalies on such modes are investigated by examining the output from two general circulation model experiments. In the first experiment (the “...

In-Sik Kang; Ngar-Cheung Lau

1986-11-01T23:59:59.000Z

351

Automatic tropical cyclone eye fix using genetic algorithm  

Science Conference Proceedings (OSTI)

Tropical cyclones (TCs) are weather systems with vast destructive power. To forecast TC tracks, forecasters need to locate their circulation centers, or eyes. This eye fix process is often done manually in practice. Since subjective elements are involved ... Keywords: Genetic algorithm, Meteorological computing, Tropical cyclone eye fix, Weather forecasting, Weather system modeling

Ka Yan Wong; Chi Lap Yip; Ping Wah Li

2008-01-01T23:59:59.000Z

352

The Direct Response to Tropical Heating in a Baroclinic Atmosphere  

Science Conference Proceedings (OSTI)

The global response to tropical heating is studied by performing a time integration of a 15-level primitive equation model, starting with a basic flow maintained by a constant forcing. The direct, quasi-steady response to the tropical heating is ...

Feifei Jin; Brian J. Hoskins

1995-02-01T23:59:59.000Z

353

A Technique for Estimating Recurrence Intervals of Tropical Cyclone-Related High Winds in the Tropics: Results for Guam  

Science Conference Proceedings (OSTI)

The authors develop a technique that applies models of the radial profile of the wind in tropical cyclones to historical best-track databases of tropical cyclones, in order to estimate the wind (at 1-h intervals) experienced at any selected ...

John A. Rupp; Mark A. Lander

1996-05-01T23:59:59.000Z

354

Ocean Barrier Layers’ Effect on Tropical Cyclone Intensification  

SciTech Connect

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

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

2012-09-04T23:59:59.000Z

355

Similarity retrieval from time-series tropical cyclone observations using a neural weighting generator for forecasting modeling  

Science Conference Proceedings (OSTI)

Building a forecasting model for time-series data is a tough but very valuable research topic in recent years. High variation of time-series features must be considered appropriately for an accurate prediction. For weather forecasting, which is continuous, ...

Bo Feng; James N. K. Liu

2005-09-01T23:59:59.000Z

356

Tropical Cyclogenesis Factors in a Warming Climate  

E-Print Network (OSTI)

Understanding the underlying causes of tropical cyclone formation is crucial to predicting tropical cyclone behavior in a warming environment, given the Earth's current warming trend. This study examines two sets of simulations from the National Center for Atmospheric Research (NCAR) Community Atmosphere Model version 3.1 (CAM3): one with aerosol forcings and one without. We looked at how four factors known to be important to tropical cyclone formation vary as carbon dioxde and the ensuing temperature changes increase to very high levels. These factors include Maximum Potential Intensity (MPI), mid-tropospheric moisture content, 200-850 mb vertical wind shear, and 850 mb absolute vorticity. We considered different representations of mid-tropospheric moisture by examining both relative humidity and chi, a non-dimensional measure of the saturation entropy deficit at 600 mb. We also looked at different combinations of these factors, including several variations of a Genesis Potential Index (GPI) and an incubation parameter, gamma, that is related to the length of time required to saturate the middle troposphere and aid tropical cyclogenesis. Higher MPI, lower saturation deficits and higher relative humidity, lower wind shear, and higher absolute vorticity all act to enhance the GPI and lower the incubation time, meaning larger environmental support for tropical cyclone development and intensification. In areas where tropical cyclone development is prevalent today, we found that shear generally decreased, but MPI decreased, absolute vorticity decreased, and the saturation deficit increases. Thus, in today's prevalent tropical cyclone regions, conditions become less favorable for development and intensification as the climate warms. On the other hand, genesis regions tend to push northward into the subtropics, as conditions become much more favorable for development up to ~40 degrees North due to both decreased wind shear and much higher MPI values.

Cathey, Stephen Christopher

2011-12-01T23:59:59.000Z

357

A Tropical Cyclone Genesis Parameter for the Tropical Atlantic  

Science Conference Proceedings (OSTI)

A parameter to evaluate the potential for tropical cyclone formation (genesis) in the North Atlantic between Africa and the Caribbean islands is developed. Climatologically, this region is the source of about 40% of the Atlantic basin tropical ...

Mark DeMaria; John A. Knaff; Bernadette H. Connell

2001-04-01T23:59:59.000Z

358

Testing ice microphysics parameterizations in the NCAR Community Atmospheric Model Version 3 using Tropical Warm Pool–International Cloud Experiment data  

SciTech Connect

Cloud properties have been simulated with a new double-moment microphysics scheme under the framework of the single column version of NCAR CAM3. For comparisons, the same simulation was made with the standard single-moment microphysics scheme of CAM3. Results from both simulations were compared favorably with observations during the Tropical Warm Pool- International Cloud Experiment by US Department of Energy Atmospheric Radiation Program in terms of the temporal variation and vertical distribution of cloud fraction and cloud condensate. Major differences between the two simulations are in the magnitude and distribution of ice water content within the mixed-phase cloud during the monsoon period, though the total frozen water (snow plus ice) content is similar. The ice mass content in the mixed-phase cloud from the new scheme is larger than that from the standard scheme, and extends 2 km further downward, which are closer to observations. The dependence of the frozen water mass fraction in total condensate on temperature from the new scheme is also closer to available observations. Outgoing longwave radiation (OLR) at the top of the atmosphere (TOA) from the simulation with the new scheme is in general larger than that with the standard scheme, while the surface downward longwave radiation is similar. Sensitivity tests suggest that different treatments of the ice effective radius contribute significantly to the difference in the TOA OLR in addition to cloud water path. The deep convection process affects both TOA OLR and surface downward longwave radiation. The over-frequently-triggered deep convention process in the model is not the only mechanism for the excess middle and high level clouds. Further evaluation especially for ice cloud properties based on in-situ data is needed.

Wang, Weiguo; Liu, Xiaohong; Xie, Shaocheng; Boyle, James; McFarlane, Sally A.

2009-07-23T23:59:59.000Z

359

Innovation Ecosystem Development Initiative  

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

Innovation Ecosystem Development Initiative Innovation Ecosystem Development Initiative Funding Opportunity Number DE-FOA-0000356 Applicant (Legal Name) University of Utah Technology Commercialization Office Location: Salt Lake City, UT Project Title Energy Innovation Commercialization Center Proposed Action or Project Description The project proposes to create an Energy Innovation Commercialization Center at the University of Utah. The scope of work for this project is in two phases: tasks necessary to create the Center and actual commercialization and outreach to other institutions. Specific activities for Phase I for the Center startup include 1) negotiating contract, prepare correspondence, establishing website, meetings, scheduling activities, developing metrics, and designing and creating a database. Phase 2 activities for Center

360

Nonlinear Response to Anomalous Tropical Forcing  

Science Conference Proceedings (OSTI)

We have investigated the nonlinear steady-state response of a barotropic model to an estimate of the observed anomalous tropical divergence forcing for the El Niño winter of 1982/83. The 400 mb climatological flow was made a forced solution of ...

R. J. Haarsma; J. D. Opsteegh

1989-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical ecosystem model" 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

Bimodality in a Monostable Climate–Ecosystem: The Role of Climate Variability and Soil Moisture Memory  

Science Conference Proceedings (OSTI)

The probabilistic modal response of vegetation to stochastic precipitation variability is studied in a conceptual climate–ecosystem model. It is found that vegetation can exhibit bimodality in a monostable climate–ecosystem under strong rainfall ...

Zhengyu Liu

2010-03-01T23:59:59.000Z

362

Hindcast/Forecast of ENSO Events Based upon the Redistribution of Observed and Model Heat Content in the Western Tropical Pacific, 1964–86  

Science Conference Proceedings (OSTI)

The redistribution of observed upper-ocean heat content in the western tropical North Pacific for the four-year period 1979–82 was shown by Pazan et al. to provide a qualitative hindcast capability for the 1982–83 ENSO event. A related study (...

Warren B. White; Stephen E. Pazan; Masamichi Inoue

1987-02-01T23:59:59.000Z

363

Innovation Ecosystem Development Initiative  

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

U.S. Department of Energy Categorical Exclusion Determination Form Program or Field Office: Office of Energy Efficiency and Renewable Energy: Innovation Ecosystem Development Initiative Funding Opportunity Number DE-FOA-0000356 Applicant (Legal Name) Fraunhofer Center for Sustainable Energy Systems Location: Cambridge, MA Project Title TechBridge Energy Innovation Acceleration Program

364

Impacts of Ocean–Atmosphere Coupling on Tropical Cyclone Intensity Change and Ocean Prediction in the Australian Region  

Science Conference Proceedings (OSTI)

This study investigates the impact of atmosphere–ocean coupling on predicted tropical cyclone (TC) intensity change and the ocean response in the Australian region. The coupled model comprises the Australian Bureau of Meteorology’s Tropical ...

P. A. Sandery; G. B. Brassington; A. Craig; T. Pugh

2010-06-01T23:59:59.000Z

365

Comparisons of Interception Loss from Tropical and Temperate Vegetation Canopies  

Science Conference Proceedings (OSTI)

A multilayer crop model is used to investigate interception loss from oak, pine, wheat and grass canopies. It is shown that the evaporative properties of the full oak canopy are similar to those of the evergreen tropical rain forest. Evaporation ...

J. G. Lockwood; P. J. Sellers

1982-10-01T23:59:59.000Z

366

Quantifying Environmental Drivers of Future Tropical Forest Extent  

Science Conference Proceedings (OSTI)

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

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

2011-03-01T23:59:59.000Z

367

Global Warming and the Weakening of the Tropical Circulation  

Science Conference Proceedings (OSTI)

This study examines the response of the tropical atmospheric and oceanic circulation to increasing greenhouse gases using a coordinated set of twenty-first-century climate model experiments performed for the Intergovernmental Panel on Climate ...

Gabriel A. Vecchi; Brian J. Soden

2007-09-01T23:59:59.000Z

368

Coupling between Gravity Waves and Tropical Convection at Mesoscales  

Science Conference Proceedings (OSTI)

An idealized cloud-system-resolving model simulation is used to examine the coupling between a tropical cloud population and the mesoscale gravity waves that it generates. Spectral analyses of the cloud and gravity wave fields identify a clear ...

Todd P. Lane; Fuqing Zhang

2011-11-01T23:59:59.000Z

369

Influence of Gravity Waves in the Tropical Upwelling: WACCM Simulations  

Science Conference Proceedings (OSTI)

The annual cycle of tropical upwelling and contributions by planetary and gravity waves are investigated from climatological simulations using the Whole Atmosphere Community Climate Model (WACCM) including three gravity wave drag (GWD) ...

Hye-Yeong Chun; Young-Ha Kim; Hyun-Joo Choi; Jung-Yoon Kim

2011-11-01T23:59:59.000Z

370

A Simplified System of Equations for Simulation of Tropical Cyclones  

Science Conference Proceedings (OSTI)

A simplified system of equations which can simulate the development and mature stages of tropical cyclones is presented. The model is similar to that presented by Ooyama, except that the assumption of incompressible fluid layers is relaxed. ...

Mark DeMaria; John D. Pickle

1988-05-01T23:59:59.000Z

371

Sensitivity of Tropical Cyclone Intensity to Sea Surface Temperature  

Science Conference Proceedings (OSTI)

Increased occurrence of more intense tropical storms intruding further poleward has been foreshadowed as one of the potential consequences of global warming. This scenario is based almost entirely on the general circulation model predictions of ...

Jenni L. Evans

1993-06-01T23:59:59.000Z

372

Probabilistic Prediction of Tropical Cyclones. Part II: Intensity  

Science Conference Proceedings (OSTI)

A new objective aid for operational probabilistic intensity (defined as maximum wind speed) prediction of tropical cyclones is presented. Based on statistical analyses of the performance of all operationally available numerical models (using ...

Harry C. Weber

2005-07-01T23:59:59.000Z

373

Probabilistic Prediction of Tropical Cyclones. Part I: Position  

Science Conference Proceedings (OSTI)

A new objective aid for operational prediction of the positions of tropical cyclones is presented. Its method is based on a simple analysis of the performance of all operationally available numerical models during a training period. In a ...

Harry C. Weber

2005-07-01T23:59:59.000Z

374

Topographic Effects on the Tropical Land and Sea Breeze  

Science Conference Proceedings (OSTI)

The effect of an inland plateau on the tropical sea breeze is considered in terms of idealized numerical experiments, with a particular emphasis on offshore effects. The sea breeze is modeled as the response to an oscillating interior heat source ...

Tingting Qian; Craig C. Epifanio; Fuqing Zhang

2012-01-01T23:59:59.000Z

375

Convective Impact on Temperatures Observed near the Tropical Tropopause  

Science Conference Proceedings (OSTI)

Observed temperature trends and interannual variations near the tropical tropopause suggest that temperatures up to the cold point are controlled by the troposphere, but some models indicate otherwise. Here, previous investigations of thermal ...

Steven C. Sherwood; Takeshi Horinouchi; Heidi A. Zeleznik

2003-08-01T23:59:59.000Z

376

Effects of Penetrative Radiation on the Upper Tropical Ocean Circulation  

Science Conference Proceedings (OSTI)

The effects of penetrative radiation on the upper tropical ocean circulation have been investigated with an ocean general circulation model (OGCM) with attenuation depths derived from remotely sensed ocean color data. The OGCM is a reduced ...

Raghu Murtugudde; James Beauchamp; Charles R. McClain; Marlon Lewis; Antonio J. Busalacchi

2002-03-01T23:59:59.000Z

377

Evaluation of Tropical Cirrus Cloud Properties and Dynamical...  

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

through the TTL into the stratosphere. The ability of large-scale models to correctly forecast tropical cirrus occurrence is important in predicting the role of these clouds on...

378

Experiments with a Simple Tropical Cyclone Intensity Consensus  

Science Conference Proceedings (OSTI)

Consensus forecasts (forecasts created by combining output from individual forecasts) have become an integral part of operational tropical cyclone track forecasting. Consensus aids, which generally have lower average errors than individual models,...

Charles R. Sampson; James L. Franklin; John A. Knaff; Mark DeMaria

2008-04-01T23:59:59.000Z

379

On the Height of the Warm Core in Tropical Cyclones  

Science Conference Proceedings (OSTI)

The warm-core structure of tropical cyclones is examined in idealized simulations using the Weather Research and Forecasting (WRF) Model. The maximum perturbation temperature in a control simulation occurs in the midtroposphere (5–6 km), in ...

Daniel P. Stern; David S. Nolan

2012-05-01T23:59:59.000Z

380

The Response of Quasigeostrophic Oceanic Vortices to Tropical Cyclone Forcing  

Science Conference Proceedings (OSTI)

The response of quasigeostrophic (QG) oceanic vortices to tropical cyclone (TC) forcing is investigated using an isopycnic ocean model. Idealized oceanic currents and wind fields derived from observational data acquired during Hurricane Katrina ...

Benjamin Jaimes; Lynn K. Shay; George R. Halliwell

2011-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical ecosystem model" 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

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

382

The Sensitivity of the Tropical-Mean Radiation Budget  

Science Conference Proceedings (OSTI)

A key disagreement exists between global climate model (GCM) simulations and satellite observations of the decadal variability in the tropical-mean radiation budget. Measurements from the Earth Radiation Budget Experiment (ERBE) over the period ...

Amy C. Clement; Brian Soden

2005-08-01T23:59:59.000Z

383

Nonlinearity of the Extratropical Response to Tropical Forcing  

Science Conference Proceedings (OSTI)

A primitive equations dry atmospheric model is used to investigate the atmospheric response to a tropical diabatic forcing pattern and explore how the atmospheric response changes as a function of the amplitude of the forcing. The forcing anomaly ...

Hai Lin; Jacques Derome

2004-07-01T23:59:59.000Z

384

A New Assessment of the Predictability of Tropical Cyclone Tracks  

Science Conference Proceedings (OSTI)

The inherent predictability of tropical cyclone tracks has received much attention since the 1980s. It is still an issue because of the recent improvement of track forecasts by numerical models. The aim of this study is to assess this ...

Matthieu Plu

2011-11-01T23:59:59.000Z

385

Simulation of the Seasonal Cycle of the Tropical Pacific Ocean  

Science Conference Proceedings (OSTI)

In a general circulation model of the tropical Pacific Ocean forced with climatological seasonally varying winds, equatorial upwelling and downwelling in adjacent latitudes play central roles in closing the oceanic circulation. The transport of ...

S. G. H. Philander; W. J. Hurlin; A. D. Seigel

1987-11-01T23:59:59.000Z

386

Some Aspects of Vortex Structure Related to Tropical Cyclone Motion  

Science Conference Proceedings (OSTI)

Some effect of tropical cyclone structure on the vortex motion are examined in a nondivergent, barotropic numerical model with no basic current. As suggested earlier by DeMaria, the initial maximum wind speed has little effect on the track. ...

Michael Fiorino; Russell L. Elsberry

1989-04-01T23:59:59.000Z

387

A Highly Configurable Vortex Initialization Method for Tropical Cyclones  

Science Conference Proceedings (OSTI)

A highly configurable vortex initialization methodology has been constructed in order to permit manipulation of the initial vortex structure in numerical models of tropical cyclones. By using distinct specifications of the flow in the boundary ...

Eric D. Rappin; David S. Nolan; Sharanya J. Majumdar

2013-10-01T23:59:59.000Z

388

Prediction of Consensus Tropical Cyclone Track Forecast Error  

Science Conference Proceedings (OSTI)

The extent to which the tropical cyclone (TC) track forecast error of a consensus model (CONU) routinely used by the forecasters at the National Hurricane Center can be predicted is determined. A number of predictors of consensus forecast error, ...

James S. Goerss

2007-05-01T23:59:59.000Z

389

A Vortical Hot Tower Route to Tropical Cyclogenesis  

Science Conference Proceedings (OSTI)

A nonhydrostatic cloud model is used to examine the thermomechanics of tropical cyclogenesis under realistic meteorological conditions. Observations motivate the focus on the problem of how a midtropospheric cyclonic vortex, a frequent by-product ...

M. T. Montgomery; M. E. Nicholls; T. A. Cram; A. B. Saunders

2006-01-01T23:59:59.000Z

390

Mechanisms of Global Warming Impacts on Regional Tropical Precipitation  

Science Conference Proceedings (OSTI)

Mechanisms that determine the tropical precipitation anomalies under global warming are examined in an intermediate atmospheric model coupled with a simple land surface and a mixed layer ocean. To compensate for the warm tropospheric temperature, ...

Chia Chou; J. David Neelin

2004-07-01T23:59:59.000Z

391

Divergent Barotropic Instability of the Tropical Asymmetric Easterly Jet  

Science Conference Proceedings (OSTI)

The divergent barotropic instability of a zonally averaged, observed, tropical, upper tropospheric, monsoon easterly jet is investigated by numerical integration of a linear spectral model. The Rossby radius of deformation for the upper ...

S. K. Mishra; D. Subrahmanyam; M. K. Tandon

1981-10-01T23:59:59.000Z

392

A Highly Configurable Vortex Initialization Method for Tropical Cyclones  

Science Conference Proceedings (OSTI)

A highly configurable vortex initialization methodology has been constructed in order to permit manipulation of the initial vortex structure in numerical models of tropical cyclones. By using distinct specifications of the flow in the boundary ...

Eric D. Rappin; David S. Nolan; Sharanya J. Majumdar

393

Tropical Cyclone Eye Thermodynamics  

Science Conference Proceedings (OSTI)

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

H. E. Willoughby

1998-12-01T23:59:59.000Z

394

Tropical Cyclone Eye Dynamics  

Science Conference Proceedings (OSTI)

A new perspective of the dynamics of a tropical cyclone eye is given in which eye subsidence and the adiabatic warming accompanying it are accounted for directly from the equations of motion. Subsidence is driven by an adverse, axial gradient of ...

R. K. Smith

1980-06-01T23:59:59.000Z

395

Tropical Cyclone Formation  

Science Conference Proceedings (OSTI)

The physics of tropical cyclone formation is not well understood, and more is known about the mature hurricane than the formative mechanisms that produce it. It is believed part of the reason for this can be traced to insufficient upper-level ...

Michael T. Montgomery; Brian F. Farrell

1993-01-01T23:59:59.000Z

396

Innovation Ecosystem Development Initiative  

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

Innovation Ecosystem Development Initiative Innovation Ecosystem Development Initiative Funding Opportunity Number DE-FOA-0000356 Applicant (Legal Name) The Regents of the University of California, UC San Diego Location: La Jolla, CA Project Title Regional Energy Innovation and Commercialization Proposed Action or Project Description The University of California San Diego and San Diego State University are partnering to address deficiencies in the process for translation of research discoveries to the private sector in the clean energy space in the greater San Diego region and accelerate the movement of clean energy innovation from the university laboratory into the marketplace. The Phase I objective for launching the Regional Energy Innovation Challenge includes tasks such as: 1) project management and planning (organizing advisory

397

Causes of interannual variability in ecosystem-atmosphere CO2 exchange in a northern Wisconsin forest using a Bayesian model calibration  

SciTech Connect

Carbon dioxide fluxes were examined over the growing seasons of 2002 and 2003 from 14 different sites in Upper Midwest (USA) to assess spatial variability of ecosystem-atmosphere CO2 exchange. These sites were exposed to similar temperature/precipitation regimes and spanned a range of vegetation types typical of the region (northern hardwood, mixed forest, red pine, jack pine, pine barrens and shrub wetland). The hardwood and red pine sites also spanned a range of stand ages (young, intermediate, mature). While seasonal changes in net ecosystem exchange (NEE) and photosynthetic parameters were coherent across the 2 years at most sites, changes in ecosystem respiration (ER) and gross ecosystem production (GEP) were not. Canopy height and vegetation type were important variables for explaining spatial variability of CO2 fluxes across the region. Light-use efficiency (LUE) was not as strongly correlated to GEP as maximum assimilation capacity (Amax). A bottom-up multi-tower land cover aggregated scaling of CO2 flux to a 2000 km(2) regional flux estimate found June to August 2003 NEE, ER and GEP to be -290 +/- 89, 408 +/- 48, and 698 +/- 73 gC m(-2), respectively. Aggregated NEE, ER and GEP were 280% larger, 32% smaller and 3% larger, respectively, than that observed from a regionally integrating 447 m tall flux tower. However, when the tall tower fluxes were decomposed using a footprint-weighted influence function and then re-aggregated to a regional estimate, the resulting NEE, ER and GEP were within 11% of the multi-tower aggregation. Excluding wetland and young stand age sites from the aggregation worsened the comparison to observed fluxes. These results provide insight on the range of spatial sampling, replication, measurement error and land cover accuracy needed for multi-tiered bottom-up scaling of CO2 fluxes in heterogeneous regions such as the Upper Midwest, USA. (C) 2007 Elsevier B.V. All rights reserved.

Ricciuto, Daniel M [ORNL; Butler, Martha [Pennsylvania State University; Davis, Kenneth [Pennsylvania State University; Cook, Bruce D [University of Minnesota, St Paul

2008-01-01T23:59:59.000Z

398

Innovation Ecosystem Development Initiative  

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

U.S. Department of Energy Categorical Exclusion Determination Form Program or Field Office: Office of Energy Efficiency and Renewable Energy: Innovation Ecosystem Development Initiative Funding Opportunity Number DE-FOA-0000356 Applicant (Legal Name) University of Central Florida Location: Orlando, FL Project Title MegaWatt Ventures Proposed Action or Project Description The University of Central Florida is dedicated to creating innovative programs that accelerate the

399

Assimilation of Subsurface Thermal Data into a Simple Ocean Model for the Initialization of an Intermediate Tropical Coupled Ocean-Atmosphere Forecast Model  

Science Conference Proceedings (OSTI)

An adjoint variational assimilation technique is used to assimilate observations of both the oceanic state and wind stress data into an intermediate coupled ENSO prediction model. This method of initialization is contrasted with the more usual ...

Richard Kleeman; Andrew M. Moore; Neville R. Smith

1995-10-01T23:59:59.000Z

400

Tropical Western Pacific  

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

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

Note: This page contains sample records for the topic "tropical ecosystem model" 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

Eastern Hemisphere Tropical Cyclones of 1996  

Science Conference Proceedings (OSTI)

This paper is an annual summary of the Eastern Hemisphere tropical cyclones of 1996. The tropical cyclone statistics presented derive from records at the Joint Typhoon Warning Center, Guam. Although the text focuses on the tropical cyclones that ...

Mark A. Lander; Eric J. Trehubenko; Charles P. Guard

1999-06-01T23:59:59.000Z

402

Eastern Hemisphere Tropical Cyclones of 1995  

Science Conference Proceedings (OSTI)

This paper is designed to be an annual summary of the Eastern Hemisphere tropical cyclones of 1995. The tropical cyclone statistics presented are those of the Joint Typhoon Warning Center, Guam. The text focuses primarily upon the tropical ...

Mark A. Lander; Michael D. Angove

1998-02-01T23:59:59.000Z

403

The Tropical Warm Pool International Cloud Experiment  

Science Conference Proceedings (OSTI)

A comprehensive dataset describing tropical cloud systems and their environmental setting and impacts has been collected during the Tropical Warm Pool International Cloud Experiment (TWP-ICE) and Aerosol and Chemical Transport in Tropical ...

Peter T. May; James H. Mather; Geraint Vaughan; Keith N. Bower; Christian Jakob; Greg M. McFarquhar; Gerald G. Mace

2008-05-01T23:59:59.000Z

404

LBA Land Use and Land Cover Data Set Released  

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

Simple Tropical Ecosystem Model Published The ORNL DAAC announces the release of the data set LBA-ECO LC-31 Simple Tropical Ecosystem Model. LBA-ECO LC-31 Simple Tropical...

405

Atlantic Tropical Systems of 1993  

Science Conference Proceedings (OSTI)

A total of 70 tropical waves (also known as African or easterly waves) were counted in the Atlantic basin during the 1993 hurricane season. These waves led to the formation of 9 of the 10 total number of tropical cyclones in the Atlantic ...

Lixion A. Avila; Richard J. Pasch

1995-03-01T23:59:59.000Z

406

Tropical Cyclone Intensity Increase near Australia as a Result of Climate Change  

Science Conference Proceedings (OSTI)

Idealized tropical cyclones are inserted into a regional climate model and the resulting intensity evolution of the storms is examined under current and enhanced greenhouse climates. The regional climate model is implemented over a model domain ...

Kevin J. E. Walsh; Brian F. Ryan

2000-08-01T23:59:59.000Z

407

Tropical Ocean Decadal Variability and Resonance of Planetary Wave Basin Modes. Part II: Numerical Study  

Science Conference Proceedings (OSTI)

Oceanic response to stochastic wind forcing is studied in a tropical–extratropical basin using two shallow water models: a periodically forced model and a time-forward model. Consistent with theory, extratropical stochastic wind forces a decadal ...

Haijun Yang; Zhengyu Liu; Qiong Zhang

2004-04-01T23:59:59.000Z

408

The Skill of ECMWF Medium-Range Forecasts during the Year of Tropical Convection 2008  

Science Conference Proceedings (OSTI)

This study uses the European Centre for Medium-Range Weather Forecasts (ECMWF) model-generated high-resolution 10-day-long predictions for the Year of Tropical Convection (YOTC) 2008. Precipitation forecast skills of the model over the tropics ...

Arindam Chakraborty

2010-10-01T23:59:59.000Z

409

Reconciling estimates of the contemporary North American carbon balance among terrestrial biosphere models, atmospheric inversions and a new approach for estimating net ecosystem exchange from inventory-based data  

Science Conference Proceedings (OSTI)

While fossil fuel emissions are calculated with relatively high precision, understanding the fate of those emissions with respect to sequestration in terrestrial ecosystems requires data and methods that can reduce uncertainties in the diagnosis of land-based CO2 sinks. The wide range in the land surface flux estimates is related to a number of factors, but most generally because of the different methodologies used to develop estimates of carbon stocks and flux, and the uncertainties inherent in each approach. The alternative approaches to estimating continental scale carbon fluxes that we explored here can be broadly classified as applying a top-down or bottom-up perspective. Top-down approaches calculate land-atmosphere carbon fluxes based on atmospheric budgets and inverse modeling. Bottom-up approaches rely primarily on measurements of carbon stock changes (the inventory approach) or on spatially distributed simulations of carbon stocks and/or fluxes using process-based modeling (the forward modelapproach).

Hayes, D. J.; Turner, D. P.; Stinson, Graham; McGuire, A. David; Wei, Yaxing; West, Tristram O.; Heath, L.; deJong, B.; McConkey, Brian; Birdsey, Richard A.; Kurz, Werner; Jacobson, Andy; Huntzinger, Deborah N.; Pan, Y.; Post, W. M.; Cook, R. B.

2012-04-02T23:59:59.000Z

410

Land conversion in Amazonia and Northern South America : influences on regional hydrology and ecosystem response  

E-Print Network (OSTI)

A numerical model of the terrestrial biosphere (Ecosystem Demography Model) is compbined with an atmospheric model (Brazilian Regional Atmospheric Modeling System) to investigate how land conversion in the Amazon and ...

Knox, Ryan Gary

2013-01-01T23:59:59.000Z

411

The Pre-Depression Investigation of Cloud-Systems in the Tropics (PREDICT) Experiment: Scientific Basis, New Analysis Tools, and Some First Results  

Science Conference Proceedings (OSTI)

The principal hypotheses of a new model of tropical cyclogenesis, known as the marsupial paradigm, were tested in the context of Atlantic tropical disturbances during the National Science Foundation (NSF)-sponsored Pre-Depression Investigation of Cloud ...

Michael T. Montgomery; Christopher Davis; Timothy Dunkerton; Zhuo Wang; Christopher Velden; Ryan Torn; Sharanya J. Majumdar; Fuqing Zhang; Roger K. Smith; Lance Bosart; Michael M. Bell; Jennifer S. Haase; Andrew Heymsfield; Jorgen Jensen; Teresa Campos; Mark A. Boothe

2012-02-01T23:59:59.000Z

412

Reconciling estimates of the contemporary North American carbon balance among terrestrial biosphere models, atmospheric inversions and a new approach for estimating net ecosystem exchange from inventory-based data  

Science Conference Proceedings (OSTI)

We develop an approach for estimating net ecosystem exchange (NEE) using inventory-based information over North America (NA) for a recent 7-year period (ca. 2000 2006). The approach notably retains information on the spatial distribution of NEE, or the vertical exchange between land and atmosphere of all non-fossil fuel sources and sinks of CO2, while accounting for lateral transfers of forest and crop products as well as their eventual emissions. The total NEE estimate of a 327 252 TgC yr1 sink for NA was driven primarily by CO2 uptake in the Forest Lands sector (248 TgC yr1), largely in the Northwest and Southeast regions of the US, and in the Crop Lands sector (297 TgC yr1), predominantly in the Midwest US states. These sinks are counteracted by the carbon source estimated for the Other Lands sector (+218 TgC yr1), where much of the forest and crop products are assumed to be returned to the atmosphere (through livestock and human consumption). The ecosystems of Mexico are estimated tobe a small net source (+18 TgC yr1) due to land use change between 1993 and 2002. We compare these inventorybased estimates with results from a suite of terrestrial biosphere and atmospheric inversion models, where the mean continental-scale NEE estimate for each ensemble is 511 TgC yr1 and 931 TgC yr1, respectively. In the modeling approaches, all sectors, including Other Lands, were generally estimated to be a carbon sink, driven in part by assumed CO2 fertilization and/or lack of consideration of carbon sources from disturbances and product emissions. Additional fluxes not measured by the inventories, although highly uncertain, could add an additional 239 TgC yr1 to the inventory-based NA sink estimate, thus suggesting some convergence with the modeling approaches.

Hayes, Daniel J [ORNL; Turner, David P [Oregon State University, Corvallis; Stinson, Graham [Pacific Forestry Centre, Canadian Forest Service; Mcguire, David [University of Alaska; Wei, Yaxing [ORNL; West, Tristram O. [Joint Global Change Research Institute, PNNL; Heath, Linda S. [USDA Forest Service; De Jong, Bernardus [ECOSUR; McConkey, Brian G. [Agriculture and Agri-Food Canada; Birdsey, Richard A. [U.S. Department of Agriculture Forest Service; Kurz, Werner [Canadian Forest Service; Jacobson, Andrew [NOAA ESRL and CIRES; Huntzinger, Deborah [University of Michigan; Pan, Yude [U.S. Department of Agriculture Forest Service; Post, Wilfred M [ORNL; Cook, Robert B [ORNL

2012-01-01T23:59:59.000Z

413

Tropical Cyclone Winds from Scatterometer Winds  

E-Print Network (OSTI)

this paper, wc demonstrate that accurate estimates of tropical cyclone intensity over data sparse ocean regions

Carol S. Hsu; W. Timothy Liu

1995-01-01T23:59:59.000Z

414

Energy, Water Ecosystem Engineering | Clean Energy | ORNL  

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

Earth and Aquatic Sciences Ecosystem Science Environmental Data Science and Systems Energy, Water and Ecosystem Engineering Human Health Risk and Environmental Analysis...

415

High school students' preconceptions and conceptions about Tropical Storm Allison  

E-Print Network (OSTI)

Today many people with no personal experience of living through a tropical storm reside in coastal regions in harm's way. There is a need to educate this population about storm risks. One good venue for this purpose is the public school system. Science educators have concluded it is important to establish a knowledge base about the various ways students think and learn in the classroom in order to design appropriate and effective instructional materials. There is also a need to fill the gap in hazards research about students' preconceptions and conceptions about these events. The purpose of this research study is to determine high school students' preconceptions and conceptions about tropical storms and the damage they do to coastal communities. This study used Lee's (1999) research study on Hurricane Andrew as a model and augments Lee's results. In-depth interviews, a survey, and class discussions with high school students living in Houston, Texas provided the data. The students, representing a wide variety of ethnic backgrounds, vary in their preconceptions and conceptions about tropical storms. The results of the data show conceptions students developed after personal experiences with Tropical Storm Allison formed most of the preconceptions they have regarding their scientific knowledge about tropical storms. Overall, students' scientific knowledge about tropical storms is poor.

Belknap, Julia

2003-01-01T23:59:59.000Z

416

Humidity-temperature relationships in the tropical troposphere  

SciTech Connect

Based on the observed interannual variations of water vapor and temperature over the past 26 years the authors have examined the relationship between the variations of water vapor and temperature in the tropical troposphere. In both the lower and upper troposphere, tropical mean specific humidity increases with temperature. The rate of fractional increase of specific humidity with temperature at 500 mb is as large as that in the surface boundary layer. However, the rate of fractional increase of specific humidity with temperature is significantly smaller than that given by a model with a fixed relative humidity, particularly in the region immediately above the tropical convective boundary layer. The variations of tropical mean relative humidity show consistently a negative correlation with the temperature variations. The authors have further compared the spatial structure of the specific humidity variations with that of the temperature variations. Though the vertical structure of tropical mean specific humidity has more variability than that of the tropical mean temperature, the leading EOF for the normalized specific humidity variations is almost exactly the same as the leading EOF for the normalized temperature variations. The characteristic horizontal structure of the specific humidity variations at levels in the free troposphere, however, is very different from that of the temperature variations. The leading EOF for the normalized specific humidty variations at levels in the free troposphere is characterized by regions with alternating positive and negative signs, while the leading EOF for the corresponding temperature variations has a single sign throughout the Tropics. When the variations are averaged zonally, the leading EOF for the normalized specific humidity variations still differs significantly from that of the normalized temperature variations, but the leading EOF has the same sign from the deep Tropics to the subtropics. 31 refs., 15 figs., 1 tab.

Sun, D.Z. [Princeton Univ., NJ (United States); Oort, A.H. [NOAA, Princeton, NJ (United States)

1995-08-01T23:59:59.000Z

417

Response of the Eastern Tropical Pacific to Meridional Migration of the ITCZ: The Generation of the Costa Rica Dome  

Science Conference Proceedings (OSTI)

A regional ocean circulation model with fine horizontal resolution has been developed in order to obtain a coherent seasonal picture of the eastern tropical Pacific off Central America.

S. Umatani; T. Yamagata

1991-02-01T23:59:59.000Z

418

Intersecting solitons, amoeba, and tropical geometry  

Science Conference Proceedings (OSTI)

We study the generic intersection (or web) of vortices with instantons inside, which is a 1/4 Bogomol'nyi-Prasad-Sommerfield state in the Higgs phase of five-dimensional N=1 supersymmetric U(N{sub C}) gauge theory on R{sub t}x(C*){sup 2}{approx_equal}R{sup 2,1}xT{sup 2} with N{sub F}=N{sub C} Higgs scalars in the fundamental representation. In the case of the Abelian-Higgs model (N{sub F}=N{sub C}=1), the intersecting vortex sheets can be beautifully understood in a mathematical framework of amoeba and tropical geometry, and we propose a dictionary relating solitons and gauge theory to amoeba and tropical geometry. A projective shape of vortex sheets is described by the amoeba. Vortex charge density is uniformly distributed among vortex sheets, and negative contribution to instanton charge density is understood as the complex Monge-Ampere measure with respect to a plurisubharmonic function on (C*){sup 2}. The Wilson loops in T{sup 2} are related with derivatives of the Ronkin function. The general form of the Kaehler potential and the asymptotic metric of the moduli space of a vortex loop are obtained as a by-product. Our discussion works generally in non-Abelian gauge theories, which suggests a non-Abelian generalization of the amoeba and tropical geometry.

Fujimori, Toshiaki [Department of Physics, Tokyo Institute of Technology Tokyo 152-8551 (Japan); Nitta, Muneto [Department of Physics, Keio University, Hiyoshi, Yokohama, Kanagawa 223-8521 (Japan); Ohta, Kazutoshi [Department of Physics, Tohoku University, Sendai 980-8578 (Japan); Sakai, Norisuke [Department of Mathematics, Tokyo Woman's Christian University, Tokyo 167-8585 (Japan); Yamazaki, Masahito [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan)

2008-11-15T23:59:59.000Z

419

Ecosystem Feedbacks to Climate Change in California: Development, Testing, and Analysis Using a Coupled Regional Atmosphere and Land Surface Model (WRF3–CLM3.5)  

Science Conference Proceedings (OSTI)

A regional atmosphere model [Weather Research and Forecasting model version 3 (WRF3)] and a land surface model [Community Land Model, version 3.5 (CLM3.5)] were coupled to study the interactions between the atmosphere and possible future ...

Z. M. Subin; W. J. Riley; J. Jin; D. S. Christianson; M. S. Torn; L. M. Kueppers

2011-05-01T23:59:59.000Z

420

A Qualitative Assessment of the Australian Tropical Region Analyses  

Science Conference Proceedings (OSTI)

The Bureau of Meteorology, Australia, routinely analyzes the tropospheric winds over the Australian Tropical Region (40°S–40°N, 70°–180°E). These wind data are assimilated without the use of a forecast model. While being free of any model bias, ...

Harry H. Hendon

1988-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical ecosystem model" 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

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

422

Self-Adapting Analog Ensemble Predictions of Tropical Cyclone Tracks  

Science Conference Proceedings (OSTI)

An analog model is used to predict the tropical cyclone tracks in the Atlantic and east Pacific basins. The model is self-adapting in its search of ensembles of optimal historic analogs by creating a norm that minimizes the forecast error ...

Oliver Sievers; Klaus Fraedrich; Christoph C. Raible

2000-10-01T23:59:59.000Z

423

Aspects of Geostrophic Adjustment during Tropical Ocean Data Assimilation  

Science Conference Proceedings (OSTI)

Subsurface temperature data from the ship-of-opportunity network in the tropical Pacific Ocean was assimilated into a simple reduced-gravity model. A large initialization shock was found to occur in the model which takes the form of equatorially ...

Andrew M. Moore

1989-04-01T23:59:59.000Z

424

Tropical Tropospheric Temperature Variations Caused by ENSO and Their Influence on the Remote Tropical Climate  

Science Conference Proceedings (OSTI)

The warming of the entire tropical free troposphere in response to El Niño is well established, and suggests a tropical mechanism for the El Niño–Southern Oscillation (ENSO) teleconnection. The potential impact of this warming on remote tropical ...

John C. H. Chiang; Adam H. Sobel

2002-09-01T23:59:59.000Z

425

Heating Rates in Tropical Anvils  

Science Conference Proceedings (OSTI)

The interaction of infrared and solar radiation with tropical cirrus anvils is addressed. Optical properties of the anvils are inferred from satellite observations and from high-altitude aircraft measurements. An infrared multiple-scattering ...

Thomas P. Ackerman; Kuo-Nan Liou; Francisco P. J. Valero; Leonhard Pfister

1988-05-01T23:59:59.000Z

426

Historical Global Tropical Cyclone Landfalls  

Science Conference Proceedings (OSTI)

In recent decades, economic damage from tropical cyclones (TCs) around the world has increased dramatically. Scientific literature published to date finds that the increase in losses can be explained entirely by societal changes (such as ...

Jessica Weinkle; Ryan Maue; Roger Pielke Jr

2012-07-01T23:59:59.000Z

427

Tropical Cyclones and Climate Change  

E-Print Network (OSTI)

Whether the characteristics of tropical cyclones have changed or will change in a warming climate — and if so, how — has been the subject of considerable investigation, often with conflicting results. Large amplitude ...

Knutson, Thomas R.

428

Microphysical Observations of Tropical Clouds  

Science Conference Proceedings (OSTI)

The results from airborne in situ sampling of convective tropical storms in the Amazon and Kwajalein are presented. Three cases from the Amazon and two from Kwajalein are compared and provide examples of the much larger dataset that was obtained ...

Jeffrey L. Stith; James E. Dye; Aaron Bansemer; Andrew J. Heymsfield; Cedric A. Grainger; Walter A. Petersen; Robert Cifelli

2002-02-01T23:59:59.000Z

429

Land-Use and Ecosystems  

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

Land-Use and Ecosystems Terrestrial Carbon Management Data Sets and Analyses National Land Cover Data 1992 (2005), and 2001 (2008) Carbon Flux to the Atmosphere from Land-Use...

430

Tropical Stationary Wave Response to ENSO: Diabatic Heating Influence on the Indian Summer Monsoon  

Science Conference Proceedings (OSTI)

The atmospheric response to boreal summer tropical diabatic heating is studied in the atmospheric model component of the Community Atmosphere Model [CAM, version 3 (CAM3)] of the National Center for Atmospheric Research. An idealized heating ...

Youkyoung Jang; David M. Straus

2013-01-01T23:59:59.000Z

431

Role of the Atmospheric and Oceanic Circulation in the Tropical Pacific SST Changes  

Science Conference Proceedings (OSTI)

A coupled climate model is used to explore the response of the tropical sea surface temperature (SST) to positive SST anomalies in the global extratropics. The main model results here are consistent with previous numerical studies. In response to ...

Jingzhi Su; Huijun Wang; Haijun Yang; Helge Drange; Yongqi Gao; Mats Bentsen

2008-05-01T23:59:59.000Z

432

Numerical Simulations and Observations of Surface Wave Fields under an Extreme Tropical Cyclone  

Science Conference Proceedings (OSTI)

The performance of the wave model WAVEWATCH III under a very strong, category 5, tropical cyclone wind forcing is investigated with different drag coefficient parameterizations and ocean current inputs. The model results are compared with field ...

Yalin Fan; Isaac Ginis; Tetsu Hara; C. Wayne Wright; Edward J. Walsh

2009-09-01T23:59:59.000Z

433

Tropical Climate Regimes and Global Climate Sensitivity in a Simple Setting  

Science Conference Proceedings (OSTI)

Multiple tropical climate regimes are found in an atmospheric general circulation model (AGCM) coupled to a global slab ocean when the model is forced by different values of globally uniform insolation. Even in this simple setting, convection ...

Joseph Barsugli; Sang-Ik Shin; Prashant D. Sardeshmukh

2005-04-01T23:59:59.000Z

434

Restratification of the Upper Ocean after the Passage of a Tropical Cyclone: A Numerical Study  

Science Conference Proceedings (OSTI)

The role of baroclinic instability in the restratification of the upper ocean after the passage of a tropical cyclone (TC) is determined by means of numerical simulations. Using a regional ocean model, the Regional Ocean Modeling System (ROMS), a ...

Wei Mei; Claudia Pasquero

2012-09-01T23:59:59.000Z

435

Empirical parameterization of Tropical Ocean–Atmosphere Coupling: The “Inverse Gill Problem”  

Science Conference Proceedings (OSTI)

A number of linear models of the steady-state response of the tropical atmosphere to sea surface temperature (SST) anomalies have been proposed, all based on the shallow-water equations. Despite their formal similarity, the various models have ...

Myles R. Allen; Michael K. Davey

1993-03-01T23:59:59.000Z

436

Attribution of Projected Future Changes in Tropical Cyclone Passage Frequency over the Western North Pacific  

Science Conference Proceedings (OSTI)

This paper performs an attribution analysis of future changes in the frequency of tropical cyclone (TC) passages over the western North Pacific basin projected by seven general circulation models. The models project increases in the passage ...

Satoru Yokoi; Yukari N. Takayabu; Hiroyuki Murakami

2013-06-01T23:59:59.000Z

437

Climatic Equilibrium of the Atmospheric Convective Boundary Layer over a Tropical Ocean  

Science Conference Proceedings (OSTI)

A one-dimensional thermodynamic model for a partially mixed, partly cloudy, convective boundary layer (CBL) is coupled to a radiation model to compute equilibrium solutions for a tropical CBL and troposphere in energy balance over the ocean. For ...

Alan K. Betts; W. Ridgway

1989-09-01T23:59:59.000Z

438

Transient Growth of Thermodynamically Coupled Variations in the Tropics under an Equatorially Symmetric Mean State  

Science Conference Proceedings (OSTI)

The dynamics of thermodynamically coupled disturbances in the tropics that bear a strong resemblance to observed meridional mode variations are investigated using two simple linear coupled models. Both models involve an ocean equation coupled to ...

Daniel J. Vimont

2010-11-01T23:59:59.000Z

439

Tropical Response to Lateral Forcing with a Latitudinally and Zonally Nonuniform Basic State  

Science Conference Proceedings (OSTI)

The tropical response to a lateral forcing is investigated with a quasi-linear numerical model of the tropical atmosphere that has a basic flow consisting of a steady planetary wave as well as a zonal shear flow. The basic flow is prescribed in ...

Jeffrey D. Wilson; Mankin Mak

1984-04-01T23:59:59.000Z

440

Extratropical Summertime Response to Tropical Interannual Variability in an Idealized GCM  

Science Conference Proceedings (OSTI)

A primitive equation model is used to investigate the role of the tropics in generating seasonal-mean anomalies in the extratropics. A nudging technique is applied to guide selected tropical regions toward 40-yr European Centre for Medium-Range ...

Nicholas M. J. Hall; Hervé Douville; Laurent Li

2013-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical ecosystem model" 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 Role of Disturbance in Dry Tropical Forest Landscapes  

Science Conference Proceedings (OSTI)

Disturbance can be defined as 'any relatively discrete event in time that disrupts ecosystem, community, or population structure and changes resources, substrate availability, or the physical environment'. This definition requires that the spatial and temporal scales of the system and disturbance be determined. Disturbances are typically characterized by their size, spatial distribution, frequency or return time, predictability, and magnitude (which includes both intensity and severity). These disturbance attributes set the parameters for the suite of species, both plant and animal, that can persist within a given system. As such, an understanding of seasonally dry tropical forests in Asia requires an understanding of disturbance within the region. However, disturbances are relatively poorly understood in dry tropical forests, partly because of the weak seasonality in temperature and high tree species diversity of these forests relative to most forest systems of the world. There are about 1,048,700 km{sup 2} of dry tropical forests worldwide and that only 3% of this land is in conservation status. In other words, 97% of the world's seasonally dry tropical forest is at risk of human disturbance. About half of this forest occurs in South America, where most of the conservation lands are located. Satellite imagery based on MODIS (Moderate Resolution Imaging Spectroradiometer) data shows that only about 3.8% of the world's dry tropical forests are in Australia and South east Asia. The susceptibility of these forests to human disturbances is of great concern and is largely unstudied. Because natural disturbance regimes shape the ecosystem structure and are in many ways integral to these forest systems, it is critical to know how natural disturbance affects dry forest in order to understand the effects of human activities on these forests. Even basic information about disturbances in dry tropical forests is only recently available. Therefore this chapter brings together much of the available information from dry tropical forest throughout the world with the goal of developing an understanding of the role of disturbance in Asian dry forests. Most ecologists now recognize that disturbances, rather than being catastrophic agents of destruction, are a normal, perhaps even an integral, part of long-term system dynamics. The composition, structure, organization, and development and trophic dynamics of most forest systems are the products of disturbances. As an example, the forest composition for two disturbances in the Anaikatty Hills of Western Ghats were compared, where the low disturbance was from past logging followed by cutting and illicit felling and grazing and the high disturbance was due to human presence, past logging, and fuelwood collection. They found higher species richness and Shannon-Wiener diversity index for the low-disturbance forest (98 and 3.9, respectively) compared to the high-disturbance stand (45 and 2.71, respectively) as well as significant differences in mean basal area of trees, density of seedlings, number of species, density and diversity of shrubs, and number of species and diversity of herbs. Some ecological systems contain species that have evolved in response to disturbances. Adaptations typical of dry tropical forest plants are drought tolerance, seed dispersal mechanisms, and the ability to sprout subsequent to disturbance. In contrast, evidence was found that human disturbance in Kakamega Forest of western Kenya has significantly reduced allelic richness and heterozygosity, increased inbreeding, and slightly reduced gene flow in Prunus africana in the past century.

Dale, Virginia H [ORNL

2011-01-01T23:59:59.000Z

442

SCRS/2005/096 Col. Vol. Sci. Pap. ICCAT, (59)2: 546-554 (2006) MULTI-SPECIES ASSESSMENT OF TUNAS CAUGHT IN THE TROPICAL  

E-Print Network (OSTI)

OF TUNAS CAUGHT IN THE TROPICAL ATLANTIC PURSE SEINE FISHERY: SENSITIVITY OF PRODUCTION MODELS TO BIASES been considered in the estimation of the species composition of the tropical tuna catch as well as in the total catch. Although three species (yellofin, skipjack and bigeye) are involved in the tropical tuna

Paris-Sud XI, Université de

443

Modeling of Energy, Water, and CO2 Flux in a Temperate Grassland Ecosystem with SiB2: May–October 1987  

Science Conference Proceedings (OSTI)

The Simple Biosphere Model, version 2 (SiB2), was designed for use within atmospheric general circulation models as a soil–vegetation–atmosphere transfer scheme that includes CO2 flux prediction. A stand-alone version of SiB2 was used to simulate ...

G. D. Colello; C. Grivet; P. J. Sellers; J. A. Berry

1998-04-01T23:59:59.000Z

444

Ranking management strategies with complex outcomes: An AHP-fuzzy evaluation of recreational fishing using an integrated agent-based model of a coral reef ecosystem  

Science Conference Proceedings (OSTI)

The management of recreational fishing requires resolving conflicting interests and is thus among the most controversial natural resource related issues. Decision making is difficult because of two main factors: first, there is lack of prediction tools ... Keywords: AHP, Agent-based model, Area closure, Decision support system, Fuzzy evaluation, Multiple criteria decision making, Non-market valuation, Random utility model, Recreational fishing

Lei Gao; Atakelty Hailu

2012-05-01T23:59:59.000Z

445

Century Model Product Available  

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

Century Model Available The ORNL DAAC announces the availability of a new model product. The model product "CENTURY: Modeling Ecosystem Responses to Climate Change, Version 4...

446

The Automated Tropical Cyclone Forecasting System (ATCF)  

Science Conference Proceedings (OSTI)

The U.S. Navy Automated Tropical Cyclone Forecasting System (ATCF) is an IBM-AT compatible software package developed for the Joint Typhoon Warning Center (JTWC), Guam. ATCF is designed to assist forecasters with the process of making tropical ...

Ronald J. Miller; Ann J. Schrader; Charles R. Sampson; Ted L. Tsui

1990-12-01T23:59:59.000Z

447

12.811 Tropical Meteorology, Spring 2005  

E-Print Network (OSTI)

This course describes the behavior and dynamics of the tropical troposphere, from the large-scale energy balance down to cumulus convection and tropical cyclones. Topics include: Radiative-convective equilibrium; the Hadley ...

Emanuel, Kerry

448

Tropical-Extratropical Interactions of Intraseasonal Oscillations  

Science Conference Proceedings (OSTI)

Tropical-extratropical interactions of intraseasonal oscillations (ISOs), based on 30 yr (1979-2009) of northern winter observations and theory, are compared. The phase relationships between the tropical signal of the leading theoretical ISO for a ...

Jorgen S. Frederiksen; Hai Lin

449

Midlevel Ventilation's Constraint on Tropical Cyclone Intensity  

E-Print Network (OSTI)

Midlevel ventilation, or the flux of low-entropy air into the inner core of a tropical cyclone (TC), is a hypothesized mechanism by which environmental vertical wind shear can constrain a tropical cyclone’s intensity. An ...

Tang, Brian Hong-An

450

A Ventilation Index for Tropical Cyclones  

E-Print Network (OSTI)

An important environmental control of both tropical cyclone intensity and genesis is vertical wind shear. One hypothesized pathway by which vertical shear affects tropical cyclones is midlevel ventilation—or the flux of ...

Tang, Brian

451

A Global Climatology of Tropical Moisture Exports  

Science Conference Proceedings (OSTI)

In a recent paper, a climatology of tropical moisture exports (TMEs) to the Northern Hemisphere (NH) was constructed on the basis of 7-day forward trajectories, started daily from the tropical lower troposphere, which were required to reach a ...

Peter Knippertz; Heini Wernli; Gregor Gläser

2013-05-01T23:59:59.000Z

452

Why Are There Tropical Warm Pools?  

Science Conference Proceedings (OSTI)

Tropical warm pools appear as the primary mode in the distribution of tropical sea surface temperature (SST). Most previous studies have focused on the role of atmospheric processes in homogenizing temperatures in the warm pool and establishing ...

Amy C. Clement; Richard Seager; Raghu Murtugudde

2005-12-01T23:59:59.000Z

453

NPP Tropical Forest: Atherton, Australia  

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

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

454

NPP Tropical Forest: Darien, Panama  

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

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

455

Dynamically Forced Increase of Tropical Upwelling in the Lower Stratosphere  

Science Conference Proceedings (OSTI)

Drivers of upwelling in the tropical lower stratosphere are investigated using the E39C-A chemistry–climate model. The climatological annual cycle in upwelling and its wave forcing are compared to the interim ECMWF Re-Analysis (ERA-Interim). The ...

Hella Garny; Martin Dameris; William Randel; Greg E. Bodeker; Rudolf Deckert

2011-06-01T23:59:59.000Z

456

A Linear Stability Analysis of Coupled Tropical Atlantic Variability  

Science Conference Proceedings (OSTI)

A linear stability analysis of an intermediate coupled ocean–atmosphere model reveals that the tropical Atlantic has two types of coupled modes: a meridional mode at the decadal time scale and a zonal mode at the interannual time scale. The ...

Faming Wang; Ping Chang

2008-06-01T23:59:59.000Z

457

Recurving Tropical Cyclones: Singular Vector Sensitivity and Downstream Impacts  

Science Conference Proceedings (OSTI)

Singular vectors (SVs) are used to study the sensitivity of 2-day forecasts of recurving tropical cyclones (TCs) in the western North Pacific to changes in the initial state. The SVs are calculated using the tangent and adjoint models of the Navy ...

Carolyn A. Reynolds; Melinda S. Peng; Jan-Huey Chen

2009-04-01T23:59:59.000Z

458

Statistical Tropical Cyclone Wind Radii Prediction Using Climatology and Persistence  

Science Conference Proceedings (OSTI)

An operational model used to predict tropical cyclone wind structure in terms of significant wind radii (i.e., 34-, 50-, and 64-kt wind radii, where 1 kt = 0.52 m s?1) at the National Oceanic and Atmospheric Administration/National Hurricane ...

John A. Knaff; Charles R. Sampson; Mark DeMaria; Timothy P. Marchok; James M. Gross; Colin J. McAdie

2007-08-01T23:59:59.000Z

459

On the Decay of Tropical Cyclone Winds Crossing Narrow Landmasses  

Science Conference Proceedings (OSTI)

A method is developed to adjust the Kaplan and DeMaria tropical cyclone inland wind decay model for storms that move over narrow landmasses. The basic assumption that the wind speed decay rate after landfall is proportional to the wind speed is ...

Mark DeMaria; John A. Knaff; John Kaplan

2006-03-01T23:59:59.000Z

460

A Simulation Study of the Landfall of Tropical Cyclones  

Science Conference Proceedings (OSTI)

By use of a triply nested, movable mesh model, several ideal simulations OF tropical Cyclone landfall were performed for a strong zonal flow of 10 m s-1. The integration domain was a 37 × 45° channel with the innermost mesh having a 22 × 22 ...

Robert E. Tuleya; Morris A. Bender; Yoshio Kurihara

1984-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical ecosystem model" 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

The Tropical Ocean Response to a Change in Solar Forcing  

Science Conference Proceedings (OSTI)

Changes in the tropical oceans caused by a shift of 6 months in the date of perihelion are examined using a coupled atmosphere–ocean general circulation model (GCM). The changes in the annual cycle of sea surface temperature (SST) near the ...

David G. DeWitt; Edwin K. Schneider

2000-03-01T23:59:59.000Z

462

Modeling the potential role of a forest ecosystem in phytostabilization and phytoextraction of 90Sr at a contaminated watershed  

SciTech Connect

The behavior of {sup 90}Sr at forest sites in the White Oak Creek watershed, near Oak Ridge, Tennessee, was simulated with a simple, site-specific, multicompartment model that linked biomass and element cycling dynamics. The model was used to predict the role of forest cover in mitigating hydrologic losses of {sup 90}Sr from contaminated soils (i.e. phytostabilization) under conditions where contaminant transport is governed mainly by shallow subsurface flow. The model was also used to predict the removal of {sup 90}Sr from soil (i.e. phytoextraction) through the growth and harvest of short rotation woody crops over a period of 30 years. Simulations with the model indicated that (1) forest preservation on the watershed is a form of phytostabilization because forest cover helps to minimize hydrologic losses of {sup 90}Sr and (2) an attempt to significantly reduce amounts of {sup 90}Sr in soil through phytoextraction would be unsuccessful. Over a period of 30 years, and under various management strategies, the model predicted that <15% of the {sup 90}Sr initially present in soil at a contaminated site was lost through hydrologic transport and <53% was lost by radioactive decay. Phytostabilization may be important in the management of radioactive land when issues like waste minimization and pollution prevention affect the selection of technologies to be used in environmental restoration.

Garten Jr, Charles T [ORNL

1999-05-01T23:59:59.000Z

463

Analytical and Numerical Studies of the Beta-Effect in Tropical Cyclone Motion. Part I: Zero Mean Flow  

Science Conference Proceedings (OSTI)

The ?-effect on tropical cyclone motion is studied using an analytical as well as a numerical model in a nondivergent barotropic framework. The analytical model and the linear version of the numerical model give essentially the same result: the ...

Johnny C. L. Chan; R. T. Williams

1987-05-01T23:59:59.000Z

464

Tropical Ocean Circulation Experiments  

Science Conference Proceedings (OSTI)

A primitive equation model of the equatorial Pacific Ocean was forced by realistic wind stress distributions over decades. Results were presented for a set of two experiments. In the first experiment the model was forced by an objectively ...

Mojib Latif

1987-02-01T23:59:59.000Z

465

Simulation of hydrologic influences on wetland ecosystem succession. Master's thesis  

Science Conference Proceedings (OSTI)

This research focuses on the development of a simulation model to determine the affects of hydrological influences on a wetland ecosystem. The model allows perturbations to the inputs of various wetland data which in turn, influences the successional development of the ecosystem. This research consisted of converting a grassland ecosystem model to one which simulates wetland conditions. The critical factor in determining the success of wetland creation is the hydrology of the system. There are four of the areas of the original model which are affected by the hydrology. The model measures the health or success of the ecosystem through the measurement of the systems gross plant production, the respiration and the net primary production of biomass. Altering the auxiliary variables of water level and the rate of flow through the system explicitly details the affects hydrologic influences on those production rates. Ten case tests depicting exogenous perturbations of the hydrology were run to identify these affects. Although the tests dealt with the fluctuation of water through the system, any one of the auxiliary variables in the model could be changed to reflect site specific data. Productivity, Hazardous material management, Hazardous material pharmacy.

Pompilio, R.A.

1994-09-01T23:59:59.000Z

466

Ecosystem feedbacks to climate change in California: Development, testing, and analysis using a coupled regional atmosphere and land-surface model (WRF3-CLM3.5)  

Science Conference Proceedings (OSTI)

A regional atmosphere model [Weather Research and Forecasting model version 3 (WRF3)] and a land surface model [Community Land Model, version 3.5 (CLM3.5)] were coupled to study the interactions between the atmosphere and possible future California land-cover changes. The impact was evaluated on California's climate of changes in natural vegetation under climate change and of intentional afforestation. The ability of WRF3 to simulate California's climate was assessed by comparing simulations by WRF3-CLM3.5 and WRF3-Noah to observations from 1982 to 1991. Using WRF3-CLM3.5, the authors performed six 13-yr experiments using historical and future large-scale climate boundary conditions from the Geophysical Fluid Dynamics Laboratory Climate Model version 2.1 (GFDL CM2.1). The land-cover scenarios included historical and future natural vegetation from the Mapped Atmosphere-Plant-Soil System-Century 1 (MC1) dynamic vegetation model, in addition to a future 8-million-ha California afforestation scenario. Natural vegetation changes alone caused summer daily-mean 2-m air temperature changes of -0.7 to +1 C in regions without persistent snow cover, depending on the location and the type of vegetation change. Vegetation temperature changes were much larger than the 2-m air temperature changes because of the finescale spatial heterogeneity of the imposed vegetation change. Up to 30% of the magnitude of the summer daily-mean 2-m air temperature increase and 70% of the magnitude of the 1600 local time (LT) vegetation temperature increase projected under future climate change were attributable to the climate-driven shift in land cover. The authors projected that afforestation could cause local 0.2-1.2 C reductions in summer daily-mean 2-m air temperature and 2.0-3.7 C reductions in 1600 LT vegetation temperature for snow-free regions, primarily because of increased evapotranspiration. Because some of these temperature changes are of comparable magnitude to those projected under climate change this century, projections of climate and vegetation change in this region need to consider these climate-vegetation interactions.

Subin, Z.M.; Riley, W.J.; Kueppers, L.M.; Jin, J.; Christianson, D.S.; Torn, M.S.

2010-11-01T23:59:59.000Z

467

Effects of nitrogen additions on above- and belowground carbon dynamics in two tropical forests  

Science Conference Proceedings (OSTI)

Anthropogenic nitrogen (N) deposition is increasing rapidly in tropical regions, adding N to ecosystems that often have high background N availability. Tropical forests play an important role in the global carbon (C) cycle, yet the effects of N deposition on C cycling in these ecosystems are poorly understood. We used a field N-fertilization experiment in lower and upper elevation tropical rain forests in Puerto Rico to explore the responses of above- and belowground C pools to N addition. As expected, tree stem growth and litterfall productivity did not respond to N fertilization in either of these Nrich forests, indicating a lack of N limitation to net primary productivity (NPP). In contrast, soil C concentrations increased significantly with N fertilization in both forests, leading to larger C stocks in fertilized plots. However, different soil C pools responded to N fertilization differently. Labile (low density) soil C fractions and live fine roots declined with fertilization, while mineral-associated soil C increased in both forests. Decreased soil CO2 fluxes in fertilized plots were correlated with smaller labile soil C pools in the lower elevation forest (R2 = 0.65, p\\0.05), and with lower live fine root biomass in the upper elevation forest (R2 = 0.90, p\\0.05). Our results indicate that soil C storage is sensitive to N deposition in tropical forests, even where plant productivity is not N-limited. The mineral-associated soil C pool has the potential to respond relatively quickly to N additions, and can drive increases in bulk soil C stocks in tropical forests.

Cusack, D.; Silver, W.L.; Torn, M.S.; McDowell, W.H.

2011-04-15T23:59:59.000Z

468

Stationary Barotropic Flow Induced by a Mountain over a Tropical Belt  

Science Conference Proceedings (OSTI)

Stationary solutions in the presence of bottom topography are computed for a tropical atmospheric belt. A primitive divergent barotropic model is assumed. An iterative time-averaging method proposed by Edelmann (1972b) is used for the purpose of ...

Fredrick H. M. Semazzi

1980-07-01T23:59:59.000Z

469

Why Tropical Sea Surface Temperature is Insensitive to Ocean Heat Transport Changes  

Science Conference Proceedings (OSTI)

Previous studies have shown that increases in poleward ocean heat transport (OHT) do not strongly affect tropical SST. The goal of this paper is to explain this observation. To do so, the authors force two atmospheric global climate models (GCMs) ...

Daniel D. B. Koll; Dorian S. Abbot

2013-09-01T23:59:59.000Z

470

Simulation of the 1976/77 Climate Transition over the North Pacific: Sensitivity to Tropical Forcing  

Science Conference Proceedings (OSTI)

This study examines the contribution of tropical sea surface temperature (SST) forcing to the 1976/77 climate transition of the winter atmospheric circulation over the North Pacific using a combined observational and modeling approach. The ...

Clara Deser; Adam S. Phillips

2006-12-01T23:59:59.000Z

471

The Influence of Atlantic Tropical Cyclones on Drought over the Eastern United States (1980–2007)  

Science Conference Proceedings (OSTI)

To assess the influence of Atlantic tropical cyclones (TCs) on the eastern U.S. drought regime, the Variable Infiltration Capacity (VIC) land surface hydrologic model was run over the eastern United States forced by the North American Land Data ...

Jonghun Kam; Justin Sheffield; Xing Yuan; Eric F. Wood

2013-05-01T23:59:59.000Z

472

Tropical Cumulus Convection and Upward-Propagating Waves in Middle-Atmospheric GCMs  

Science Conference Proceedings (OSTI)

It is recognized that the resolved tropical wave spectrum can vary considerably among general circulation models (GCMs) and that these differences can have an important impact on the simulated climate. A comprehensive comparison of low-latitude ...

T. Horinouchi; S. Pawson; K. Shibata; U. Langematz; E. Manzini; M. A. Giorgetta; F. Sassi; R. J. Wilson; K. Hamilton; J. de Grandpré; A. A. Scaife

2003-11-01T23:59:59.000Z

473

Impact Of Cumulus Initialization on the Spinup of Precipitation Forecasts in the Tropics  

Science Conference Proceedings (OSTI)

In order to ameliorate the precipitation spinup problem (prediction models’ inability to produce realistic precipitation rates at the beginning of the forecast period), the impact of a tropical initialization procedure on precipitation forecasts ...

Akira Kasahara; Arthur P. Mizzi; Leo J. Donner

1992-07-01T23:59:59.000Z

474

Tropical Cyclogenesis Sensitivity to Environmental Parameters in Radiative-Convective Equilibrium  

E-Print Network (OSTI)

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

Nolan, David S.

475

The Response of the Tropical Atmosphere to Low Frequency Thermal Forcing  

Science Conference Proceedings (OSTI)

The tropical response to a localized thermal forcing with approximately 45-day period is investigated for several models of increasing complexity consisting of two equivalent shallow water system and two fully stratified systems. The fully ...

John R. Anderson; Duane E. Stevens

1987-02-01T23:59:59.000Z

476

Dynamics of the Extratropical Response to a Tropical Atlantic SST Anomaly  

Science Conference Proceedings (OSTI)

Previous atmospheric general circulation model (AGCM) experiments revealed that atmospheric responses to a tropical Atlantic sea surface temperature anomaly (SSTA) were asymmetric with respect to the sign of the SSTA. A positive SSTA produced a ...

Shuanglin Li; Walter A. Robinson; Martin P. Hoerling; Klaus M. Weickmann

2007-02-01T23:59:59.000Z

477

Poleward-Propagating Angular Momentum Perturbations Induced by Zonally Symmetric Heat Sources in the Tropics  

Science Conference Proceedings (OSTI)

A series of experiments has been performed using an idealized model of the global atmosphere to study the role eddies play in communicating changes in the zonal mean state between the Tropics and extratropics. When an oscillatory heating ...

Edmund K. M. Chang

1998-06-01T23:59:59.000Z

478

Effects of Enhanced Shortwave Absorption on Coupled Simulations of the Tropical Climate System  

Science Conference Proceedings (OSTI)

The effects of enhanced shortwave absorption on coupled simulations of the tropical climate have been tested using the National Center for Atmospheric Research Climate System Model. The enhancement in cloudy-sky shortwave absorption is consistent ...

William D. Collins

2001-03-01T23:59:59.000Z

479

The Linear and Nonlinear Extratropical Response of the Atmosphere to Tropical Intraseasonal Heating  

Science Conference Proceedings (OSTI)

This study examines the dynamical nature of the linear and nonlinear extratropical response of the atmosphere to tropical intraseasonal heating with various temporal and spatial structures. A global two-level model is used. It is found that the ...

Ileana Bladé; Dennis L. Hartmann

1995-12-01T23:59:59.000Z

480

Eddy Formation in the Tropical Atlantic Induced by Abrupt Changes in the Meridional Overturning Circulation  

Science Conference Proceedings (OSTI)

The variability of the meridional overturning circulation (MOC) in the upper tropical Atlantic basin is investigated using a reduced-gravity model in a simplified domain. Four sets of idealized numerical experiments are performed: (i) switch-on ...

Marlos Goes; David P. Marshall; Ilana Wainer

2009-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "tropical ecosystem model" 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.


481

Walker-Type Mean Circulations and Convectively Coupled Tropical Waves as an Interacting System  

Science Conference Proceedings (OSTI)

Interactions between convectively coupled tropical waves and Walker-type mean circulations are examined using a two-dimensional analytic model wherein drying and cooling of the boundary layer by convective and mesoscale downdrafts are in ...

Jun-Ichi Yano; Mitchell W. Moncrieff; Wojciech W. Grabowski

2002-05-01T23:59:59.000Z

482

A GCM Simulation of the Relationship between Tropical-Storm Formation and ENSO  

Science Conference Proceedings (OSTI)

A low-resolution Geophysical Fluid Dynamics Laboratory (GFDL) general circulation model has been integrated for 15 years. In the course of this experiment, the observed month-to-month sea surface temperature (SST) variations in the tropical ...

Guoxiong Wu; Ngar-Cheung Lau

1992-06-01T23:59:59.000Z

483

Volcanic and Solar Forcing of the Tropical Pacific over the Past 1000 Years  

Science Conference Proceedings (OSTI)

The response of El Niño to natural radiative forcing changes over the past 1000 yr is investigated based on numerical experiments employing the Zebiak–Cane model of the tropical Pacific coupled ocean–atmosphere system. Previously published ...

Michael E. Mann; Mark A. Cane; Stephen E. Zebiak; Amy Clement

2005-02-01T23:59:59.000Z

484

Seasonal Predictability and Spatial Coherence of Rainfall Characteristics in the Tropical Setting of Senegal  

Science Conference Proceedings (OSTI)

This study examines space–time characteristics of seasonal rainfall predictability in a tropical region by analyzing observed data and model simulations over Senegal. Predictability is analyzed in terms of the spatial coherence of observed ...

Vincent Moron; Andrew W. Robertson; M. Neil Ward

2006-11-01T23:59:59.000Z

485

A History of Western North Pacific Tropical Cyclone Track Forecast Skill  

Science Conference Proceedings (OSTI)

The tropical cyclone (TC) track forecasting skill of operational numerical weather prediction (NWP) models and their consensus is examined for the western North Pacific from 1992 to 2002. The TC track forecasting skill of the operational NWP ...

James S. Goerss; Charles R. Sampson; James M. Gross

2004-06-01T23:59:59.000Z

486

A Numerical Study of Lapse-Rate Adjustments in the Tropical Atmosphere  

Science Conference Proceedings (OSTI)

Observations in the tropics have shown that the lapse rate of virtual Potential temperature ?v normally resembles that of a reversible moist adiabat. In the present study, a mesoscale numerical model with parameterized convection is used to ...

Charles Cohen; William M. Frank

1989-08-01T23:59:59.000Z

487

An Analytic Vortex Initialization Technique for Idealized Tropical Cyclone Studies in AGCMs  

Science Conference Proceedings (OSTI)

The paper discusses the design of idealized tropical cyclone experiments in atmospheric general circulation models (AGCMs). The evolution of an initially weak, warm-core vortex is investigated over a 10-day period with varying initial conditions ...

Kevin A. Reed; Christiane Jablonowski

2011-02-01T23:59:59.000Z

488

A Vortex Relocation Scheme for Tropical Cyclone Initialization in Advanced Research WRF  

Science Conference Proceedings (OSTI)

This paper introduces a relocation scheme for tropical cyclone (TC) initialization in the Advanced Research Weather Research and Forecasting (ARW-WRF) model and demonstrates its application to 70 forecasts of Typhoons Sinlaku (2008), Jangmi (2008)...

Ling-Feng Hsiao; Chi-Sann Liou; Tien-Chiang Yeh; Yong-Run Guo; Der-Song Chen; Kang-Ning Huang; Chuen-Teyr Terng; Jen-Her Chen

2010-08-01T23:59:59.000Z

489

Global Ensemble Predictions of 2009’s Tropical Cyclones Initialized with an Ensemble Kalman Filter  

Science Conference Proceedings (OSTI)

Verification was performed on ensemble forecasts of 2009 Northern Hemisphere summer tropical cyclones (TCs) from two experimental global numerical weather prediction ensemble prediction systems (EPSs). The first model was a high-resolution ...

Thomas M. Hamill; Jeffrey S. Whitaker; Michael Fiorino; Stanley G. Benjamin

2011-02-01T23:59:59.000Z

490

Interannual Biases Induced by Freshwater Flux and Coupled Feedback in the Tropical Pacific  

Science Conference Proceedings (OSTI)

Freshwater flux (FWF) forcing–induced feedback has not been represented adequately in many coupled ocean–atmosphere models of the tropical Pacific. Previously, various approximations have been made in representing the FWF forcing in climate ...

Rong-Hua Zhang; Guihua Wang; Dake Chen; A. J. Busalacchi; E. C. Hackert

2010-05-01T23:59:59.000Z

491

The Dynamical Basis of Regional Vertical Motion Fields Surrounding Localized Tropical Heating  

Science Conference Proceedings (OSTI)

A series of real-data integrations of the National Center for Atmospheric Research Community Climate Model with tropical heat anomalies display regions of pronounced subsidence and drying surrounding the anomaly. The present emphasis is upon ...

Julio Buchmann; Lawrence E. Buja; Julia Nogués-Paegle; Jan Paegle

1995-05-01T23:59:59.000Z

492

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

493

The effect of moist convection on the tropospheric response to tropical and subtropical zonally asymmetric torques  

Science Conference Proceedings (OSTI)

Tropospheric winds can be altered by vertical transfers of momentum due to orographic gravity waves and convection. Previous work showed that, in dry models, such zonally asymmetric torques produce a pattern of tropical ascent that is well-...

William R. Boos; Tiffany A. Shaw

494

Dynamical and Physical Processes Leading to Tropical Cyclone Intensification under Upper-Level Trough Forcing  

Science Conference Proceedings (OSTI)

The rapid intensification of Tropical Cyclone (TC) Dora (2007, southwest Indian Ocean) under upper-level trough forcing is investigated. TC–trough interaction is simulated using a limited-area operational numerical weather prediction model. The ...

Marie-Dominique Leroux; Matthieu Plu; David Barbary; Frank Roux; Philippe Arbogast

2013-08-01T23:59:59.000Z

495

Improvements of an Ice-Phase Microphysics Parameterization for Use in Numerical Simulations of Tropical Convection  

Science Conference Proceedings (OSTI)

It is important to properly simulate the extent and ice water content of tropical anvil clouds in numerical models that explicitly include cloud formation because of the significant effects that these clouds have on the radiation budget. For this ...

Steven K. Krueger; Qiang Fu; K. N. Liou; Hung-Neng S. Chin

1995-01-01T23:59:59.000Z

496

Organization of Tropical Convection in Low Vertical Wind Shears: The Role of Water Vapor  

Science Conference Proceedings (OSTI)

A modeling study is conducted to gain insight into the factors that control the intensity and organization of tropical convection, and in particular to examine if organization occurs in the absence of factors such as vertical wind shear or ...

Adrian M. Tompkins

2001-03-01T23:59:59.000Z

497

Toward improved tropical cyclone intensity forecasts : probabilistic prediction, predictability, and the role of verification  

E-Print Network (OSTI)

Over the past two decades, deterministic predictions of tropical cyclone (TC) intensity consistently scored poorly in mean absolute error (MAE) verification, despite the concurrent advancement of TC modeling and observing ...

Moskaitis, Jonathan Robert

2009-01-01T23:59:59.000Z

498

Seasonal Prediction of Tropical Cyclone Activity Near Taiwan Using the Bayesian Multivariate Regression Method  

Science Conference Proceedings (OSTI)

A Poisson generalized linear regression model cast within a Bayesian framework is applied to forecast the seasonal tropical cyclone (TC) counts in the vicinity of Taiwan. The TC season considered is June–November and the data period used for ...

Mong-Ming Lu; Pao-Shin Chu; Yun-Ching Lin

2010-12-01T23:59:59.000Z

499

Tropical Cyclone Genesis Factors in Simulations of the Last Glacial Maximum  

Science Conference Proceedings (OSTI)

Large-scale environmental factors that favor tropical cyclogenesis are calculated and examined in simulations of the Last Glacial Maximum (LGM) from the Paleoclimate Modelling Intercomparison Project Phase 2 (PMIP2). Despite universally colder ...

Robert L. Korty; Suzana J. Camargo; Joseph Galewsky

2012-06-01T23:59:59.000Z

500

Sensitivities and Mechanisms of the Zonal Mean Atmospheric Circulation Response to Tropical Warming  

Science Conference Proceedings (OSTI)

Although El Niño and global warming are both characterized by warming in the tropical upper troposphere, the latitudinal changes of the Hadley cell edge and midlatitude eddy-driven jet are opposite in sign. Using an idealized dry atmospheric model,...

Lantao Sun; Gang Chen; Jian Lu

2013-08-01T23:59:59.000Z