Modeling the Generation of Haida Eddies E. Di Lorenzo1, M.G. G. Foreman2, W.R. Crawford2 1Scripps Institution of Oceanography, University of California, San Diego, USA 2Institute of Ocean Sciences, Fisheries and Oceans Canada, Sidney, British Columbia, Canada Accepted for publication in Deep Sea Research II Revision January, 2004 1Corresponding author mailing address: Physical Oceanography Research Division Scripps Institution of Oceanography University of California, San Diego 9500 Gilman Drive , La Jolla, CA 92093-0213 Tel: (858) 534-6397 FAX: (858) 534-8561 e-mail:
[email protected] FedEx address: 8810 Shellback Way, 439 Nierenberg Hall KEYWORDS: Gulf of Alaska, anticyclonic eddies, Haida eddy, buoyancy flows 1 Modeling the Generation of Haida Eddies E. Di Lorenzo1, M.G. G. Foreman2, W.R. Crawford2 1Scripps Institution of Oceanography, University of California, San Diego, USA 2Institute of Ocean Sciences, Fisheries and Oceans Canada, Sidney, British Columbia, Canada Abstract A numerical model forced with average annual cycles of climatological winds, surface heat flux, and temperature and salinity along the open boundaries is used to demonstrate that Haida Eddies are typically generated each winter off Cape St. James, at the southern tip of the Queen Charlotte Islands of western Canada. Annual cycles of sea surface elevation measured at coastal tide gauges and TOPEX/POSEIDON crossover locations are reproduced with reasonable accuracy. Model sensitivity studies show that Haida Eddies are baroclinic in nature and are generated by the merging of several smaller eddies that have been formed to the west of Cape St. James. The generation mechanism does not require the existence of instability processes and is associated with the mean advection of warmer and fresher water masses around the cape from Hecate Strait and from the southeast.