Anomalous eddy heat and freshwater transport in the Gulf of Alaska. Issue 2 (25th February 2015)

• Record Type: Journal Article
• Authors: Lyman, John M.; Johnson, Gregory C.
• Is Part Of: Journal of geophysical research. Volume 120:Issue 2(2015:Feb.)
• Page Start: 1397
• Page End: 1408
• Publication Date: 2015-02-25
• Subjects: ocean heat content -- fresh water -- eddies -- Gulf of Alaska -- sea surface height; Oceanography -- Periodicals; 551.4605
• DOI: 10.1002/2014JC010252
• Languages: English
• ISSNs: 2169-9275

Abstract

Abstract: Characteristics of eddies in the Gulf of Alaska are assessed from January 2003 through April 2012. Ensemble statistics for eddy subsurface water properties on isopycnals are computed using temperature and salinity profiles from Argo profiling floats located within eddies, which are identified in sea‐surface height using objective techniques. Ninety cyclonic and 154 anticyclonic eddies are identified during this period. The anticyclonic eddies are strongly nonlinear and exhibit significant warm subsurface temperature anomalies and associated salty anomalies on isopycnals while no clear distinguishing subsurface anomalies on isopycnals are detected in association with the cyclonic eddies. Heat and freshwater fluxes for the eddies are estimated from integrations in depth coordinates. The anticyclonic eddies transport heat both westward off the continental shelf into the Subarctic Gyre and westward within the Alaskan Stream. However, they transport salt into the Subarctic Gyre and freshwater within the Alaskan Stream. In both pathways eddy heat and freshwater transport show possible year‐to‐year fluctuations, varying from 0 to 50.4 × 10 18 J a −1 and −16.8 to +7.4 km 3 a −1, respectively. The anticyclonic eddies are capped by relatively fresh water year‐round. Key Points: Gulf of Alaska subsurface eddy heat and freshwater fluxes are estimated Eddy locations from sea‐surface height maps are combined with Argo profile data Strongly nonlinear anticyclonic eddies have large property anomalies and fluxes