Interannual variation of summertime stationary eddies

Abstract

Equatoral λ-t diagrams of sea surface temperature (SST), outgoing longwave radiation (OLR), the potential function of OLR (χOLR), and velocity potential (χ) derived from NMC analyses reveal the existence of a coherent and pronounced interannual variation, particularly over the Pacific. Performing regular EOF analyses of eddy streamfunction and velocity potential departures from their multiple-summer averages at 200 mb [ψE(200 mb)] and correlating the distributions between these two variables, it is possible to identify two interannual variation modes of summertime stationary eddies. The horizontal structure of these two interannual variation modes which differs from the Pacific-North American (PNA) teleconnection pattern, resembles the Matsuno-Gill type of tropically trapped modes. -from Authors