Ocean biogeochemical carbon cycle process

@The ocean exchanges carbon dioxide (CO2) with the atmosphere. The CO2 exchange is in the direction from the higher to the lower concentration (or partial pressure), and the exchange rate is proportional to the difference in CO2 partial pressure (pCO2) between the ocean and the atmosphere. When CO2 dissolves in sea water, most of the carbon is in the form of bicarbonate ion (HCO3-) and carbonate ion (CO32-) through the carbonate chemical reaction. Total concentration of dissolved CO2 gas, HCO3-, and CO32- is defined as dissolved inorganic carbon (DIC). Total concentration of electrical charge of HCO3- and CO32- is defined as alkalinity because these ions neutralize H+ ion. pCO2 in the carbonate chemical equilibrium is calculated by use of DIC concentration, alkalinity, temperature, and salinity. The calculated pCO2 is used for the sea-air CO2 exchange.
@DIC in the upper ocean is reduced by the biological production of particulate organic carbon and calcite, which are exported to the deep ocean; new production. The production rate is mostly proportional to the insolation and phosphate concentration in the upper ocean. The particulate organic carbon and calcite exported to the deep ocean dissolve in sea water by remineralization or dissolution, respectively, which increases DIC in the deep ocean. These biological processes are parameterized by the observations. DIC and other dissolved biogeochemical elements are also redistributed by the advection and diffusion of the ocean general circulation model.


JMA > MRI > Comprehensive Projection of Climate Change around Japan due to the Global Warming > Development of Earth System Model for Global Warming Projection > Ocean biogeochemical carbon cycle process

Mar.2008
by Team GW of MRI
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