Horizontal Structure and Energetics of Northern Hemisphere Wintertime Teleconnection Patterns

Abstract

Abstract The horizontal structure and dynamical properties of the teleconnection patterns in the interannual variability of the Northern Hemisphere wintertime 500 mb height field are investigated. Regression maps based on indices for the eastern Atlantic (EA), Pacific/North American (PNA), western Atlantic (WA), western Pacific (WP) and Eurasian (EU) patterns defined by Wallace and Gutzler are used to define the geographically fixed patterns. Space-spectrum analysis including a spherical harmonic decomposition is applied to these maps. Anomalous geostrophic wind fields derived from these regression maps are used to estimate the kinetic energy conversion between the climatological mean state and the wave structures associated with the teleconnection patterns. The teleconnection patterns comprise “seesaw” and/or wavelike structures. In general, the kinetic energy of the teleconnection patterns is concentrated in total wavenumber n = 5 and 6 components with zonal wavenumbers m = 0, 1 and 2, which correspond ...