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Export of nutrients from the Arctic Ocean
Author(s) -
TorresValdés Sinhué,
Tsubouchi Takamasa,
Bacon Sheldon,
NaveiraGarabato Alberto C.,
Sanders Richards,
McLaughlin Fiona A.,
Petrie Brian,
Kattner Gerhard,
AzetsuScott Kumiko,
Whitledge Terry E.
Publication year - 2013
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1002/jgrc.20063
Subject(s) - arctic , nutrient , oceanography , silicate , nitrate , environmental science , hydrography , geology , chemistry , ecology , biology , organic chemistry
This study provides the first physically based mass‐balanced transport estimates of dissolved inorganic nutrients (nitrate, phosphate, and silicate) for the Arctic Ocean. Using an inverse model‐generated velocity field in combination with a quasi‐synoptic assemblage of hydrographic and hydrochemical data, we quantify nutrient transports across the main Arctic Ocean gateways: Davis Strait, Fram Strait, the Barents Sea Opening (BSO), and Bering Strait. We found that the major exports of all three nutrients occur via Davis Strait. Transports associated with the East Greenland Current are almost balanced by transports associated with the West Spitsbergen Current. The most important imports of nitrate and phosphate to the Arctic occur via the BSO, and the most important import of silicate occurs via Bering Strait. Oceanic budgets show that statistically robust net silicate and phosphate exports exist, while the net nitrate flux is zero, within the uncertainty limits. The Arctic Ocean is a net exporter of silicate (−15.7 ± 3.2 kmol s −1 ) and phosphate (−1.0 ± 0.3 kmol s −1 ; net ± 1 standard error) to the North Atlantic. The export of excess phosphate (relative to nitrate) from the Arctic, calculated at −1.1 ± 0.3 kmol s −1 , is almost twice as large as previously estimated. Net transports of silicate and phosphate from the Arctic Ocean provide 12% and 90%, respectively, of the net southward fluxes estimated at 47 ° N in the North Atlantic. Additional sources of nutrients that may offset nutrient imbalances are explored, and the relevance and the pathway of nutrient transports to the North Atlantic are discussed.