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Ocean eddy freshwater flux convergence into the North Atlantic subtropics
Author(s) -
Gordon Arnold L.,
Giulivi Claudia F.
Publication year - 2014
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1002/2013jc009596
Subject(s) - eddy , subtropics , flux (metallurgy) , salinity , oceanography , climatology , ekman transport , environmental science , sea surface temperature , thermohaline circulation , ocean current , ocean dynamics , temperature salinity diagrams , geology , atmospheric sciences , geography , meteorology , turbulence , fishery , materials science , upwelling , metallurgy , biology
For a quasi steady state condition, the water vapor flux from the ocean to atmosphere typical of the salty subtropics must be compensated by ocean processes that transfer freshwater into the evaporative regime. Observations of the North Atlantic subtropical sea surface salinity maximum region frequently reveal the presence of eddies with distinct salinity/temperature signatures of up to 0.2 psu/1°C, with horizontal scales of up to 200 km. Using the surface layer salinity and meridional velocity from the Simple Ocean Data Assimilation (SODA) reanalysis data, we find that the eddy flux can accomplish 50% to 75% of the required freshwater convergence into the subtropical regime, the rest being delivered by Ekman transport convergence, and therefore represents a significant component of the marine hydrological cycle. Interannual fluctuations of the eddy freshwater flux are reflected in sea surface salinity variability.