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The annual cycle of iron and the biological response in central California coastal waters
Author(s) -
Johnson Kenneth S.,
Chavez Francisco P.,
Elrod Virginia A.,
Fitzwater Steve E.,
Pennington J. Timothy,
Buck Kurt R.,
Walz Peter M.
Publication year - 2001
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 - 10.1029/2000gl012433
Subject(s) - upwelling , oceanography , submarine pipeline , annual cycle , environmental science , nitrate , phytoplankton , ecosystem , marine ecosystem , geology , nutrient , climatology , ecology , biology
Iron has been measured for 16 months with ∼21 day resolution at three stations in the upwelling ecosystem of central California, providing the first detailed assessment of the annual iron cycle in the coastal zone. A large pulse of iron occurs during the first spring upwelling event of the year. Iron concentrations then decay up to 100‐fold over several months, although upwelling continues. Excess surface nitrate and low iron are the result during the summer and fall at the two stations furthest offshore (20 and 45 km), while nitrate is depleted and iron high nearshore (5 km). Phytoplankton biomass, primary production and community structure appear to be controlled by iron concentrations in offshore waters during this period.