Subgrid-Scale Mixing in Climate Models: A Novel Look at Diffusion, Accuracy, Stability and Climate Sensitivity

Rood, Richard B ; Jablonowski, Christiane

关键词: Climate Model;    Weather Model;    Numerical Methods;    Transport;    Sub-scale Mixing;   

DOI  :  10.2172/1054064
RP-ID  :  DOEER64446
PID  :  OSTI ID: 1054064

学科分类：环境科学（综合）

美国|英语

来源: SciTech Connect

【 摘 要 】

This project focuses on evaluating the role of subgrid-scale dissipation in the dynamical core of atmospheric models. All dynamical cores of atmospheric general circulation models (GCMs) employ some form of subgrid-scale dissipation, either explicitly specified or inherent in the chosen numerical schemes. The dissipation processes are needed to keep the simulation stable or to satisfy important physical properties, and the hope is that they capture and mimic in some poorly understood way the true processes at the unresolved subgrid scale. There is no physical basis that such dissipation can accomplish this. We originally posed a set of numerical test cases chosen or designed to isolate the role of the filters and fixers on both the dynamical variables (pressure, temperature, velocity, vorticity) and trace constituents. From these test case results, we synthesize the information to determine the impact of the subgrid-scale assumptions on weather and climate models.