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Eddies enhance biological production in the Weddell‐Scotia Confluence of the Southern Ocean
Author(s) -
Kahru M.,
Mitchell B. G.,
Gille S. T.,
Hewes C. D.,
HolmHansen O.
Publication year - 2007
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2007gl030430
Subject(s) - eddy , isopycnal , oceanography , anticyclone , circumpolar star , phytoplankton , front (military) , geology , chlorophyll a , mixed layer , seawifs , ocean color , polar front , biomass (ecology) , frontogenesis , environmental science , hydrography , climatology , nutrient , satellite , meteorology , geography , mesoscale meteorology , ecology , biology , botany , aerospace engineering , turbulence , engineering
Satellite data show that oceanic eddies generated in the Southern Antarctic Circumpolar Current Front (SACCF) are associated with increased phytoplankton biomass. Cyclonic eddies with high chlorophyll a concentration (Chl‐a) retain phytoplankton within the eddy cores and increase the light available for photosynthesis in the upper mixed layer by limiting vertical mixing and lifting of the isopycnal surfaces. Anticyclonic eddies have low Chl‐a in the core but increased Chl‐a in the periphery. Cross‐frontal mixing mediated by eddies transports nutrients (e.g., Fe and Si) to the north and contributes to the increased Chl‐a in the frontal zone. Interannual variations in the cyclonic eddy activity are positively correlated with variations in Chl‐a during the spring bloom in regions of the Antarctic Circumpolar Current around South Georgia.