Open AccessBuoyant Eddies Entering the Labrador Sea Observed with Gliders and Altimetry
Author(s) -
Hjálmar Hátún,
Charles C. Eriksen,
Peter B. Rhines
Publication year - 2007
Publication title -
journal of physical oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.706
H-Index - 143
eISSN - 1520-0485
pISSN - 0022-3670
DOI - 10.1175/2007jpo3567.1
Subject(s) - eddy , ocean gyre , geology , boundary current , baroclinity , oceanography , hydrography , anticyclone , altimeter , ocean current , climatology , convection , temperature salinity diagrams , salinity , sea surface height , sea surface temperature , geodesy , meteorology , geography , subtropics , turbulence , biology , fishery
Intense, buoyant anticyclonic eddies spawned from the west Greenland boundary current were observed with high-resolution autonomous Seaglider hydrography and satellite altimetry as they entered the Labrador Sea interior. Surveys of their internal structure establish the transport of both low-salinity water in the upper ocean and warm, saline Irminger water at depth. The observed eddies can contribute significantly to the rapid restratification of the Labrador Sea interior following wintertime deep convection. These eddies have saline cores between 200 and 1000 m, low-salinity cores above 200 m, and a velocity field that penetrates to at least 1000 m, with 0–1000-m average speeds exceeding 40 cm s−1. Their trajectory, together with earlier estimates of the gyre circulation, suggests why the observed region of deep convection is so small and does not occur where wintertime cooling by the atmosphere is most intense. The cyclostrophic surface velocity field of the anticylones from satellite altimetry matched well with in situ dynamic height baroclinic velocity calculations.