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Dependence of the ocean‐atmosphere partitioning of carbon on temperature and alkalinity
Author(s) -
Omta Anne Willem,
Dutkiewicz Stephanie,
Follows Michael J.
Publication year - 2011
Publication title -
global biogeochemical cycles
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.512
H-Index - 187
eISSN - 1944-9224
pISSN - 0886-6236
DOI - 10.1029/2010gb003839
Subject(s) - alkalinity , atmosphere (unit) , biogeochemical cycle , environmental science , carbon cycle , carbon fibers , atmospheric sciences , arrhenius equation , climatology , chemistry , meteorology , geology , ecosystem , physics , ecology , environmental chemistry , materials science , biology , activation energy , organic chemistry , composite number , composite material
We develop and extend a theoretical framework to analyze the impacts of changes in temperature and alkalinity on the ocean‐atmosphere carbon partitioning. When investigating the impact of temperature, we assume that there is no change in the global ocean alkalinity. This idealized situation is probably most relevant on intermediate timescales of hundreds to thousands of years. Our results show that atmospheric pCO 2 depends approximately exponentially on the average ocean temperature, since the chemical equilibria involved have an exponential (Arrhenius‐type) dependence. The dependence of pCO 2 on alkalinity is more complicated, and our theory suggests several regimes. The current ocean‐atmosphere system appears to have an exponential dependence of pCO 2 on global mean ocean alkalinity, but at slightly higher alkalinities, the dependence becomes a power law. We perform experiments with a numerical physical‐biogeochemical model to test the validity of our analytical theory in a more complex, ocean‐like system: in general, the numerical results support the analytical inferences.