CO2 Exchanges between the Ocean and the Atmosphere
Abstract The global carbon cycle is strongly controlled by the ocean because it is the largest carbon reservoir at the Earth surface and it absorbs 25% of the anthropogenic CO2 emissions. The net ocean–atmosphere CO2 flux is controlled by a thermodynamic pump (CO2 solubility is higher when water get...
Main Authors: | , |
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Format: | Book Part |
Language: | English |
Published: |
Oxford University PressOxford
2016
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Subjects: | |
Online Access: | http://dx.doi.org/10.1093/acprof:oso/9780198787495.003.0008 https://academic.oup.com/book/chapter-pdf/51185041/acprof-9780198787495-chapter-8.pdf |
Summary: | Abstract The global carbon cycle is strongly controlled by the ocean because it is the largest carbon reservoir at the Earth surface and it absorbs 25% of the anthropogenic CO2 emissions. The net ocean–atmosphere CO2 flux is controlled by a thermodynamic pump (CO2 solubility is higher when water get colder) and a biological pump (photosynthesis consumes CO2). Hence carbon is transferred from the surface ocean to the deep ocean by downwelling of cold and dense waters and by sinking of dead organic matter. In the surface ocean, the average dissolved CO2 concentration increases at the same rate than the atmospheric CO2. The buffering effect of carbonate system chemical equilibria amplifies carbon storage and reduces the lowering of the pH also called acidification. Elemental and isotopic tracers show that anthropic CO2 has invaded the thermocline and has started spreading in the deep Atlantic ocean with NADW and AABW. |
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