The structure, energetics and evolution of the dominant frequency- dependent three-dimensional atmospheric modes.

Abstract

The winter-time circulation of the Northern Hemisphere is examined for the following time-scale classes: A) greater than 45 days, B) 20-45 days, C) 10-20 days, D) 6-10 days and E) 2.5-6 days. The spatial structure of variability within each of these frequency bands is determined by an empirical orthogonal function expansion of the coupled vertical mean and difference streamfunction fields. The winter average barotropic and baroclinic energy sources and sinks associated with the time-mean winter flow are examined in the context of a two-layer quasi-geostrophic model. -from Author