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in subjects: "General Circulation Models"

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Variability of surface fluxes over a heterogeneous semi-arid grassland

Efforts are increasing throughout the research community to improve the predictive capabilities of general circulation models (GCMs). The US Department of Energy's Atmospheric Radiation Measurement (ARM) program has stated its goals as improving the representation and parameterization of cloud radiative forcing and feedbacks in GCMs by a combined modeling and experimental approach. Along with ambient atmospheric conditions, including advection of water vapor and cloud nuclei from other regions,… more

Date: January 1, 1991

Creator: Barnes, F.J.; Porch, W.; Cooper, D. (Los Alamos National Lab., NM (United States)); Kunkel, K.E. (Illinois Univ., Urbana, IL (United States)); Hipps, L. & Swiatek, E. (Utah State Univ., Logan, UT (United States))

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Influences of clouds and rain on the large-scale transport and deposition of sulfur

This paper describes the application of a three-dimensional, global-scale Eulerian model with an explicit description of cloud and chemical processes. Simulation results describing the transport of sulfur from North America and Europe across the north Atlantic Ocean during a climatological July are presented. Wet deposition was found to contribute slightly more to total sulfur deposition than dry deposition, a feature explained by the large amounts of precipitation during this month. The wet de… more

Date: July 1, 1991

Creator: Luecken, D.J.; Berkowitz, C.M. & Easter, R.C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Development and testing of an air quality model for Mexico City

Los Alamos National Laboratory and Instituto Mexicano del Petroleo have embarked on a joint study of options for improving air quality in Mexico City. The intent is to develop a modeling system which can address the behavior of pollutants in the region so that option for improving Mexico City air quality can be properly evaluated. In February of 1991, the project conducted a field program which yielded a variety of data which is being used to evaluate and improve the models. Normally the worst … more

Date: March 2, 1992

Creator: Williams, M. D.; Streit, G. (Los Alamos National Lab., NM (United States)); Cruz, X.; Ruiz, M.; Sosa, G. (Instituto Mexicano de Petroleo, Mexico City (Mexico)); Russell, A. G. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Simulation of the carbon cycle in the ocean

A dual carbon-nitrogen biological model of the upper ocean has been developed, which has successfully allowed predictions of fluxes of carbon between atmosphere and the deep ocean to made. Regarding studying the carbon cycle in the ocean, the modelling has highlighted the need for a good understanding of the interactions between the carbon and nitrogen cycles, and also the importance of zooplankton grazing and levels of overwintering biological stocks. Problems have been encountered with the ac… more

Date: September 16, 1991

Creator: Fasham, M.J.R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Gaussian dispersion and dosimetric modeling sensitivity to area-specific 1982--86 meteorological data collected at the Savannah River Site

Radiological dose to the offsite maximum individual or the 50-mile population is often estimated assuming that operational atmospheric releases originate from the geographical center of the Savannah River Site. Historically, meteorological data collected from instrumentation on the H-Area tower have been utilized to estimate atmospheric dispersion from centrally located releases.'' This paper examines the effect on dose predictions using meteorological data from seven onsite towers located at A… more

Date: September 13, 1991

Creator: Hamby, D. M. & Parker, M. J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Atmospheric radiation measurement: A program for improving radiative forcing and feedback in general circulation models

The Atmospheric Radiation Measurement (ARM) Program is a key element of the Department of Energy's (DOE's) global change research strategy. ARM represents a long-term commitment to conduct comprehensive studies of the spectral atmospheric radiative energy balance profile for a wide range of cloud conditions and surface types, and to develop the knowledge necessary to improve parameterizations of radiative processes under various cloud regimes for use in general circulation models (GCMs) and rel… more

Date: January 1, 1991

Creator: Patrinos, A.A. (USDOE, Washington, DC (United States)); Renne, D.S.; Stokes, G.M. (Pacific Northwest Lab., Richland, WA (United States)) & Ellingson, R.G. (Maryland Univ., College Park, MD (United States))

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Analysis of general circulation model results and comparison with regional climatic data, Task 3

On time scales of greater than one year the variability of weather and climate on a large path of the Earth is dominated by the Southern Oscillation. While current theories of this phenomenon have clarified the role of the interaction between the ocean and the atmosphere in maintaining this oscillation it has so far been unclear whether the Southern Oscillation originates in the ocean, in the atmosphere or during the interaction between the ocean and the atmosphere. In this study we compared si… more

Date: January 1, 1989

Creator: Cess, R.D. & Hameed, S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

ARM tropical pacific experiment (ATPEX): Role of cloud, water vapor and convection feedbacks in the coupled ocean/atmosphere system

We have initiated studies that include radiation model validation, improved treatment of the three-dimensional structure of cloud-radiation interactions, and sensitivity runs that will unravel the role of cloud-convection-radiation interactions in the Pacific Sear Surface Temperatures and the overlying Walker and Hadley circulation. The research program is divided into three phases: (1) radiation, (2) cloud parameterization issues; (3) feedback and ocean-atmosphere interactions.

Date: March 5, 1992

Creator: Ramanathan, V. & Barnett, T.P.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

The use of ARM data to test an improved parameterization of upper tropospheric clouds for use in climate models

We have proposed to provide and further develop an advanced finite-difference climate model for use in CHAMMP. The model includes advanced parameterizations of cumulus convection, boundary-layer processes, cloud formation, and land-surface vegetation, as well as parameterizations of radiative transfer and gravity wave drag. Postprocessing codes and a user's guide will also be provided.

Date: May 1992

Creator: Randall, D.A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Regional-scale simulations of the western United States climate

Mesoscale models can provide a sufficiently detailed regional climatology. From these pioneering studies, we were inspired to begin to develop regional climatologies with the Colorado State University Regional Atmospheric Modeling System (CSU-RAMS). Our major goal is to develop a better understanding of the hydrologic cycle in the mountainous, arid west. An advantage of using the RAMS code is that we can generate detailed descriptions of precipitation processes, which will hopefully translate i… more

Date: September 1, 1991

Creator: Bossert, J.E.; Kao, C.-Y.J. (Los Alamos National Lab., NM (United States)); Roads, J.O.; Chen, Shyh-C. & Ueyoshi, Kyozo (Scripps Institution of Oceanography, La Jolla, CA (United States))

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

A 3-D dynamical/chemical GCM for simulating the anthropogenical effects on ozone

In spite of the significantly increased attention atmospheric ozone has received over the last two decades or so, a fully quantitative understanding of the three-dimensional ozone structure remains unavailable. In the past, one-dimensional (vertical column) models have provided most of the quantitative simulations of atmospheric chemical systems, because these models can treat large ensembles of chemical process economically. More recently, two-dimensional (meridional cross section) models have… more

Date: January 1, 1989

Creator: Kao, C. Y. J.; Glatzmaier, G. A.; Malone, R. C. & Turco, R. P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Real-time statistical quality control and ARM

An important component of the Atmospheric Radiation Measurement (ARM) Program is real-time quality control of data obtained from meteorological instruments. It is the goal of the ARM program to enhance the predictive capabilities of global circulation models by incorporating in them more detailed information on the radiative characteristics of the earth's atmosphere. To this end, a number of Cloud and Radiation Testbeds (CART's) will be built at various locations worldwide. Each CART will consi… more

Date: May 1, 1992

Creator: Blough, D.K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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National Institute for Global Environmental Change

This document is the Semi-Annual Report of the National Institute for Global Environmental Change for the reporting period July 1 to December 31, 1991. The report is in two parts. Part I presents the mission of the Institute, examples of progress toward that mission, a brief description of the revised management plan, and the financial report. Part II presents the statements of the Regional Center Directors along with progress reports of the projects written by the researchers themselves.

Date: April 1, 1992

Creator: Werth, G.C.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Recent changes of weather patterns in North America

The objectives of this report are (1) to analyze the time related changes and variability in the property and frequency of air masses and the weather extremes over North America; and, (2) to determine to what degree the observed changes agree with the predictions based on climate models. Climate models predict a general increase of surface air temperature and drought over parts of the North American continent due to increased CO{sub 2} concentrations. Regional climate change results in part fro… more

Date: April 1, 1992

Creator: Kukla, G.J. & Gavin, J.E.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Development of an advanced finite-difference atmospheric general circulation model

Date: March 1992

Creator: Randall, D.A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Radiative Forcing by Long-Lived Greenhouse Gases: Calculations with the AER Radiative Transfer Models

A primary component of the observed, recent climate change is the radiative forcing from increased concentrations of long-lived greenhouse gases (LLGHGs). Effective simulation of anthropogenic climate change by general circulation models (GCMs) is strongly dependent on the accurate representation of radiative processes associated with water vapor, ozone and LLGHGs. In the context of the increasing application of the Atmospheric and Environmental Research, Inc. (AER) radiation models within the … more

Date: April 1, 2008

Creator: Collins, William; Iacono, Michael J.; Delamere, Jennifer S.; Mlawer, Eli J.; Shephard, Mark W.; Clough, Shepard A. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

On The Reproducibility of Seasonal Land-surface Climate

The sensitivity of the continental seasonal climate to initial conditions is estimated from an ensemble of decadal simulations of an atmospheric general circulation model with the same specifications of radiative forcings and monthly ocean boundary conditions, but with different initial states of atmosphere and land. As measures of the ''reproducibility'' of continental climate for different initial conditions, spatio-temporal correlations are computed across paired realizations of eleven model… more

Date: October 22, 2004

Creator: Phillips, T J

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

A Parallel Ocean Model With Adaptive Mesh Refinement Capability For Global Ocean Prediction

An ocean model with adaptive mesh refinement (AMR) capability is presented for simulating ocean circulation on decade time scales. The model closely resembles the LLNL ocean general circulation model with some components incorporated from other well known ocean models when appropriate. Spatial components are discretized using finite differences on a staggered grid where tracer and pressure variables are defined at cell centers and velocities at cell vertices (B-grid). Horizontal motion is model… more

Date: September 8, 2005

Creator: Herrnstein, A

Item Type: Thesis or Dissertation

Partner: UNT Libraries Government Documents Department

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The Community Climate System Model Project from an Interagency Perspective

In 2007, the Intergovernmental Panel on Climate Change (IPCC) will publish its Fourth Assessment Report of the Scientific Basis of Climate Change (AR4). A significant portion of the AR4 will be the analysis of coupled general circulation model (GCM) simulations of the climate of the past century as well as scenarios of future climates under prescribed emission scenarios. Modeling groups worldwide have contributed to AR4, including three from the U.S., the Community Climate System Model (CCSM) p… more

Date: June 16, 2005

Creator: Bader, D C; Bamzai, A; Fein, J; Patrinos, A & Leinen, M

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Climate Forcings and Climate Sensitivities Diagnosed from Coupled Climate Model Integrations

A simple technique is proposed for calculating global mean climate forcing from transient integrations of coupled Atmosphere Ocean General Circulation Models (AOGCMs). This 'climate forcing' differs from the conventionally defined radiative forcing as it includes semi-direct effects that account for certain short timescale responses in the troposphere. Firstly, we calculate a climate feedback term from reported values of 2 x CO{sub 2} radiative forcing and surface temperature time series from 7… more

Date: July 25, 2006

Creator: de F. Forster, Piers & Taylor, Karl E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Wintertime pytoplankton bloom in the Subarctic Pacific supportedby continental margin iron

Heightened biological activity was observed in February 1996in the high-nutrient low-chlorophyll (HNLC) subarctic North PacificOcean, a region that is thought to beiron-limited. Here we provideevidence supporting the hypothesis that Ocean Station Papa (OSP) in thesubarctic Pacific received a lateral supply of particulate iron from thecontinental margin off the Aleutian Islands in the winter, coincidentwith the observed biological bloom. Synchrotron X-ray analysis was usedto describe the physica… more

Date: June 8, 2004

Creator: Lam, Phoebe J.; Bishop, James K.B.; Henning, Cara C.; Marcus,Matthew A.; Waychunas, Glenn A. & Fung, Inez

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Towards Ultra-High Resolution Models of Climate and Weather

We present a speculative extrapolation of the performance aspects of an atmospheric general circulation model to ultra-high resolution and describe alternative technological paths to realize integration of such a model in the relatively near future. Due to a superlinear scaling of the computational burden dictated by stability criterion, the solution of the equations of motion dominate the calculation at ultra-high resolutions. From this extrapolation, it is estimated that a credible kilometer … more

Date: January 1, 2007

Creator: Wehner, Michael; Oliker, Leonid & Shalf, John

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Anthropogenically-Induced Climate Change: Final Report

Paper number 1 addresses the fact that the procedure used in the Earth Radiation Budget Experiment for identifying the presence of clouds over snow/ice surfaces is known to have shortcomings, and this is corroborated through use of surface insolation measurements at the South Pole as an independent means of identifying clouds. These surface insolation measurements are then used to validate the more detailed cloud identification scheme used in the follow-up Clouds and the Earth's Radiant Energy … more

Date: December 5, 2008

Creator: Cess, Robert D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Impact of Geoengineering Schemes on the Global Hydrological Cycle

The rapidly rising CO{sub 2} level in the atmosphere has led to proposals of climate stabilization via 'Geoengineering' schemes that would mitigate climate change by intentionally reducing the solar radiation incident on earth's surface. In this paper, we address the impact of these climate stabilization schemes on the global hydrological cycle, using equilibrium simulations from an atmospheric general circulation model coupled to a slab ocean model. We show that insolation reductions sufficien… more

Date: December 7, 2007

Creator: Bala, G.; Duffy, P. & Taylor, K.

Item Type: Article

Partner: UNT Libraries Government Documents Department