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Ocean circulation and biogeochemistry moderate interannual and decadal surface water pH changes in the Sargasso Sea
Author(s) -
Goodkin Nathalie F.,
Wang BoShian,
You ChenFeng,
Hughen Konrad A.,
GrumetProuty Nancy,
Bates Nicholas R.,
Doney Scott C.
Publication year - 2015
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 - 10.1002/2015gl064431
Subject(s) - biogeochemical cycle , biogeochemistry , oceanography , sargasso sea , seawater , ocean current , hydrography , environmental science , atmosphere (unit) , climatology , geology , chemistry , environmental chemistry , geography , meteorology
Abstract The oceans absorb anthropogenic CO 2 from the atmosphere, lowering surface ocean pH, a concern for calcifying marine organisms. The impact of ocean acidification is challenging to predict as each species appears to respond differently and because our knowledge of natural changes to ocean pH is limited in both time and space. Here we reconstruct 222 years of biennial seawater pH variability in the Sargasso Sea from a brain coral, Diploria labyrinthiformis . Using hydrographic data from the Bermuda Atlantic Time‐series Study and the coral‐derived pH record, we are able to differentiate pH changes due to surface temperature versus those from ocean circulation and biogeochemical changes. We find that ocean pH does not simply reflect atmospheric CO 2 trends but rather that circulation/biogeochemical changes account for >90% of pH variability in the Sargasso Sea and more variability in the last century than would be predicted from anthropogenic uptake of CO 2 alone.