Session: C32 Poster: W122B Effects of stratospheric ozone depletion, solar UV radiation, and climate change on oceanic CO2 sink and source strengths: Interactions and feedbacks
Of the ~10 petagrams (Pg) carbon that are annually emitted into the atmosphere via fossil fuel burning and land use change, approximately 30 % are taken up by terrestrial ecosystems, 25 % by the global ocean, and the rest accumulates in the atmosphere (Canadell et al., 2007). Hence the global ocean...
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Language: | English |
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Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.672.9707 http://conference2011.wcrp-climate.org/abstracts/C32/Sulzberger_C32_W122B.pdf |
Summary: | Of the ~10 petagrams (Pg) carbon that are annually emitted into the atmosphere via fossil fuel burning and land use change, approximately 30 % are taken up by terrestrial ecosystems, 25 % by the global ocean, and the rest accumulates in the atmosphere (Canadell et al., 2007). Hence the global ocean is a net CO2 sink. However, coupled climate-carbon models suggest that the oceans, particularly the Southern Ocean will become progressively less efficient at taking up CO2 under global warming (Canadell et al., 2007; Lenton et al., 2009). This paper discusses processes that could decrease the oceanic CO2 sink strength and increase the oceanic CO2 source strength. Decreasing oceanic CO2 sink strengths could be due to (i) the reduction of the CO2 air-sea gradient as a result of enhanced ventilation of carbon-rich deep water through stronger winds thus increasing surface water CO2 (Lenton et al., 2009), and (ii) decreasing efficiency of the biological pump due to negative impacts of solar UV-B radiation and climate change on phytoplankton (Zepp et al., 2011). Increasing oceanic CO2 source strengths, on the other hand, could be a result of enhanced mineralization of organic carbon (OC) due to the combined effects of solar UV radiation and climate change on OC bioavailability (Zepp et al., 2011). Regarding (i), stratospheric polar ozone depletion in conjunction with increasing greenhouse gas concentrations has been shown to lead to an upward trend of the |
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