Quasi-Geostrophic Potential Vorticity Transport in the Northern and Southern Hemispheres and Simple Climate Models

Abstract

The meridional transport of quasi-geostrophic potential vorticity is calculated for the Northern and Southern Hemispheres. The results show that the transport of potential vorticity is negative over most of the atmosphere except over a thin layer near surface where it is positive. Exchange coefficients for the transport of potential vorticity are computed for both the hemispheres using the evaluations of the transport of quasi-geostrophic potential vorticity and calculating the meridional gradient of potential vorticity. The values of the exchange coefficients are used in a simple, two-level quasi-geostrophic numerical model for tonally averaged conditions. The model is applied to the Northern and Southern Hemispheres and the general characteristics of mean annual temperature and zonal wind variation are reproduced reasonably well.