Tropical-extratropical Interactions in a Hierarchy of Atmospheric Models

Princeton University, Princeton NJ

Investigators

Abstract

A hierarchy of idealized large-scale models of the atmosphere will be constructed. The models range from quasi-geostrophic beta-plane models, to dry primitive equation models on the sphere, to idealized moist primitive equation models on the sphere, all with zonally symmetric climates. These models will be used to study a number of problems in general circulation theory that are relevant to both climate change studies and to weather and climate forecast model development. The dynamical problems to be studied fall into two classes: 1) the sensitivity of the position of the mid-latitude jet streams to such factors as the strength of the Hadley cell, the strength of surface friction, the stratospheric polar vortex, the tropopause height, and the amount of water vapor in the atmosphere; and 2) the sensitivity of the strength of tropical circulation features such as the Hadley cell and the position of the InterTropical Convergence Zone (ITCZ) to perturbations to the Earth's energy balance in both high and low latitudes. The overall goal is to help close the gap between idealized theories of the general circulation and the high-end modeling that is practiced with comprehensive general circulation models. The hierarchy of models will be made available as a resource to the community. This resource should be of value for education in the university community, as well as to research, particularly to young researchers and those with limited model development resources.