Mesoscale variability in the boundary currents of the Alaska Gyre

Measurements of sea-surface height anomalies acquired during the GEOSAT. ER S-1. and TOPEX altimeter missions show that the boundary currents of the Al aska gyre exhibit interannual variability with respect to the occurrence, s ize, and propagation of mesoscale. eddy-like features. Observations and mod el results suggest that eddies are generated in the Alaska Current during y ears in which the wind forcing in the eastern Gulf of Alaska promotes stron g downwelling along the British Columbia-Alaska coast. Wind forcing conditi ons that support eddy formation and intensification often occur in years th at coincide with El Nino-Southern Oscillation events. Eddy variability is s ignificantly more deterministic in the Alaska Current than in the Alaskan S tream. (C) 2001 Elsevier Science Ltd. All rights reserved.