Multi-year meanders and eddies in the Alaskan Stream as observed by TOPEX/Poseidon altimeter

Abstract

The birth, life and decay of long-lived anti-cyclonic eddies, or meanders, in the Alaskan Stream are observed from TOPEX/Poseidon (T/P) satellite. Their surface height anomalies approach 72 cm, average diameter is about 160km and they live for 1 to 3 years, propagating along the Stream with mean speed of 2.5 km d -1. Of the six observed, the last three were formed after the first T/P observations in September 1992. Of these, two evolved from eddies near Alaskan Panhandle in winter, drifting across the northern Gulf of Alaska before entering the Alaskan Stream, while another formed in the Stream west of Shelikof Strait.