Monthly mean global satellite data sets available in CCM history tape format

Satellite data for climate monitoring have become increasingly important over the past decade, especially with increasing concern for inadvertent antropogenic climate change. Although most satellite based data are of short record, satellites can provide the global coverage that traditional meteorological observations network lack. In addition, satellite data are invaluable for the validation of climate models, and they are useful for many diagnostic studies. Herein, several satellite data sets were processed and transposed into 'history tape' format for use with the Community Climate Model (CCM) modular processor. Only a few of the most widely used and best documented data sets were selected at this point, although future work will expand the number of data sets examined as well as update the archived data sets. An attempt was made to include data of longer record and only monthly averaged data were processed. For studies using satellite data over an extended period, it is important to recognize the impact of changes in instrumentation, drift in instrument calibration, errors introduced by retrieval algorithms and other sources of errors such as those resulting from insufficient space and/or time sampling

A Review Paper: Contributions from the Gravity and the Kelvin Modes for the Vertical Motion Response.

In earlier papers of a series of real data integrations of the National Center for Atmospheric Research (NCAR) Community Climate Model (CCM) with tropical heat anomalies display regions of pronounced subsidence and drying located several thousand kilometers westward poleward of the heating for cases of tropical Atlantic heating and tropical east Pacific heating. This highly predictable sinking response is established within the first five days of these integrations. The normal-modes of a set of nonlinear primitive equations for an atmosphere: Adiabatic, hydrostatic, incompressible, dry, without friction and viscosity are linearized about a basic state at rest and used to partition model response into gravity-inertia and Rossby modes. The emphasis of this review is given upon the contributions of the gravity and Kelvin modes for the vertical motion response

Nonlinear dynamics of global atmospheric and Earth-system processes

General Circulation Model (GCM) studies of the atmospheric response to change boundary conditions are discussed. Results are reported on an extensive series of numerical studies based on the National Center for Atmospheric Research (NCAR) Community Climate Model (CCM) general circulation model. In these studies the authors determined the response to systematic changes in atmospheric CO2 ranging from 100 to 1000 ppm; to changes in the prescribed sea surface temperature (SST) in the Gulf of Mexico, such as occurred during the deglaciation phase of the last ice age; to changes in soil moisture over North America; and to changes in sea ice extent in the Southern Hemisphere. Study results show that the response of surface temperature and other variables is nearly logarithmic, with lower levels of CO2 implying greater sensitivity of the atmospheric state to changes in CO2. It was found that the surface temperature of the Gulf of Mexico exerts considerable control over the storm track and behavior of storm systems over the North Atlantic through its influence on evaporation and the source of latent heat. It was found that reductions in soil moisture can play a significant role in amplifying and maintaining North American drought, particularly when a negative soil moisture anomaly prevails late in the spring

Lane Processes in a High Resolution Community Climate Model with Sub-Grid Scale Prameterizations

Many crucial processes occur on spatial scales too fine to be resolved by most current climate models. This grant addressed the need for and development of a high-resolution, fine-mesh global model for these processes. The proposed research represented a natural continuation of our current CHAMMP project, which concentrated on the development of earlier versions of a high-resolution land surface model coupled to various versions of the NCAR Community Climate Model (CCM). Sub-grid land processes are represented by a sub-mesh imposed on each atmospheric model grid square, rather than by the more common mosaic approach. The main objective of this grant was to upgrade the current fine-mesh model configuration to a 0.2o sub-mesh representation within a T-239L semi-Lagrangian version of the NCAR Community Climate Model (CCM). An initial test of the sub-mesh approach carried out simulations using the standard T-42 CCM but with a 0.75o (T-239L) sub-mesh representation of land processes and compared these with a complete T-239L simulation. Besides the land sub-mesh parameterizations, including rainfall, snow, radiation, near-surface variables, topographic effects, and land heterogeneity within the sub-mesh, it impremented other improvements within land surface parameterizations coupled to the CCM including treatments of near-surface boundary layers, soil layer structure, snow, and vegetation

The effect of latent heat release on synoptic-to-planetary scale wave interactions and implications for satellite observations: Observational study

Researchers have been exploring methods to facilitate the prediction of rapidly intensifying surface cyclones. Recognizing that synoptic-scale systems, such as these cyclones, are less predictable at medium range and beyond than are planetary-scale circulations, researchers propose that the planetary-scale environment for explosive cyclogenesis could be better predicted than the cyclones themselves. Researchers have therefore constructed a planetary-scale climatology of explosive cyclogenesis by compositing together filtered 500 mb height fields (retaining planetary waves only) corresponding to a large sample of rapidly intensifying surface cyclones, stratified geographically and according to the direction of 500 mb geostrophic flow (southwesterly, northwesterly or westerly) over the cyclone center. The composites are calculated from five days preceding to five days following each rapid cyclogenesis event, and have climatology subtracted so that the evolution of planetary-scale anomalies before and after cyclogenesis can be followed. Whether the anomalies are distinct from background variability and thus provide predictive value is now being evaluated. Following explosive cyclogenesis over which the filtered 500 mb flow is southwesterly, there appear in the composites large positive 500 mb height anomalies downstream. In some cases, these anomalies are associated with blocking patterns. Whether the objectively-defined blocking patterns in the data set are preceded by upstream intense surface cyclone activity is being investigated. Finally, the contribution of synoptic-scale processes, notably warm air advection, to planetary-scale height rises during a block formation following an explosive cyclogenesis event is being diagnosed. Researchers hope to eventually evaluate the impact of satellite derived latent heat release upon the warm air advection in this case

Uma revisão: contribuições dos modos de gravidade e de Kelvin para a resposta do movimento vertical

In earlier papers of a series of real data integrations of the National Center for Atmospheric Research (NCAR) Community Climate Model (CCM) with tropical heat anomalies display regions of pronounced subsidence and drying located several thousand kilometers westward poleward of the heating for cases of tropical Atlantic heating and tropical east Pacific heating. This highly predictable sinking response is established within the first five days of these integrations. The normal-modes of a set of nonlinear primitive equations for an atmosphere: Adiabatic, hydrostatic, incompressible, dry, without friction and viscosity are linearized about a basic state at rest and used to partition model response into gravity-inertia and Rossby modes. The emphasis of this review is given upon the contributions of the gravity and Kelvin modes for the vertical motion response.Uma série de integrações do Modelo da Comunidade Climática do Centro Nacional de Pesquisas Atmosféricas com uma fonte anômala tropical de calor mostra regiões de pronunciada subsidência e de seca localizadas a 3000 km a oeste da fonte de calor em direção aos pólos para casos do Atlântico e do Pacifico leste tropicais aquecidos.A alta predictabilidade do movimento descendente e estabelecida dentro dos cinco primeiros dias destas integrações. Os modos normais do conjunto de equações primitivas não lineares para uma atmosfera: Adiabática, hidrostática, incompressível, seca, sem atrito e viscosidade são linearizadas com relação ao estado básico em repouso e usadas para a partição da resposta do modelo em modos de inércia gravidade e de Rossby. A ênfase desta revisão e dada para as contribuições dos modos de gravidade e de Kelvin para a resposta do movimento vertical

Contribuições do segundo e do terceiro modos internos de gravidade para a resposta do movimento vertical

In earlier papers of 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 located several thousand kilometers westward poleward of the heating for cases of tropical Atlantic heating and tropical east Pacific heating. This highly predictable sinking response is established within the first five days of these integrations. The normal-modes of a set of adiabatic primitive equations linearized about a basic state at rest are used to partition model response into gravity-inertia and Rossby modes. The most important contribution for the vertical motion response comes from the gravity modes added for all vertical modes. The principal emphasis is given upon the contributions of the second and third internal vertical modes (with equivalent depths on the order of a fews hundred meters) for the vertical motion responseUma série de integrações do Modelo Climático do Centro Nacional de Pesquisas Atmosféricas com uma fonte anômala tropical de calor mostra regiões de pronunciada subsidência e de seca localizadas a 3000 km a oeste da fonte de calor em direção aos pólos para casos do Atlântico e do Pacifico leste tropicais aquecidos. A alta predictabilidade do movimento descendente e estabelecida dentro dos cinco primeiros dias destas integrações. Os modos normais do conjunto de equações primitivas (adiabática) linearizadas com relação ao estado básico em repouso são usadas para a partição da resposta do modelo em modos de inércia gravidade e de Rossby. A mais importante contribuição para a resposta do movimento vertical, advém dos modos de gravidade somados para todos os modos verticais. A principal ênfase e dada para as contribuições do segundo e terceiro modo vertical interno para resposta do movimento vertica

Initial Conditions for a Post-Flood Rapid Ice Age

In the early years of the modern creationist movement questions were raised as to the role of ice ages in explaining geological data. Beginning with Whitcomb and Morris (1961) and formalized by Oard (1979), a proposed scenario of warm oceans and volcanic activity would provide the needed conditions to initiate a post-flood ice age. During the 1990’s Vardiman used the Community Climate Model (CCM) to study the impact of warm oceans on global air circulation and precipitation patterns. Following Vardiman’s lead this study uses the Goddard Institute of Space Studies (GISS) Model E climate model. The first part of the study uses a fixed 30 ºC sea surface temperature to validate against work done by Spelman (1996). The second part of the study incorporates a dynamic ocean as well as increased volcanic aerosol levels to determine the initial conditions needed to provide snowfall rates of significant intensity to initiate accumulation for an ice age. Given initial sea surface temperatures of 30 ºC, extensive volcanic activity is needed to offset the heat flux provided by warm oceans. The Model E simulations had run times of six years and did not achieve the conditions needed for extensive snowfall at high latitudes. Using a dynamic ocean and volcanic aerosol optical depths of 2.00 give promise of sufficient cooling if the simulation were to extend to several decades. Given the limited run times, these simulations can only provide information about the sensitivity of the climate model and the thermodynamic balance over a limited time scale. Future work using century long runs will provide more conclusive results about the validity of the initial conditions proposed here. Extended runs will also provide valuable information about climate shifts as well as changes in circulation patterns within the ocean, which can then be compared to geological strata associated with the Pleistocene

Angular momentum budget in General Circulation Models of superrotating atmospheres: A critical diagnostic

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96272/1/jgre3137.pd

Model documentation, chapter 4

The modeling groups are listed along with a brief description of the respective models