0 199 1, by the American Society of Limnology and Oceanography, Inc. Three-dimensional simulations of the impact of Southern Ocean nutrient depletion on atmospheric CO2 and ocean chemistry

Surface nutrient concentrations in the Southern Ocean are an important indicator of the atmosphere-ocean chemical balance that played a key role in ice-age reduction of atmospheric pC0, and would play a role in any Fe fertilization scenario for increasing oceanic uptake of anthropogenic CO,. The res...

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Bibliographic Details
Main Authors: Jorge L. Sarmiento, James C. Orr
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Subjects:
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.144.2703
http://www.gfdl.noaa.gov/reference/bibliography/1991/jls9101.pdf
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Summary:Surface nutrient concentrations in the Southern Ocean are an important indicator of the atmosphere-ocean chemical balance that played a key role in ice-age reduction of atmospheric pC0, and would play a role in any Fe fertilization scenario for increasing oceanic uptake of anthropogenic CO,. The response of the ocean and atmosphere to a scenario of extreme depletion of Southern Ocean surface nutrients by an increase in the organic matter flux to the deep ocean is examined with a three-dimensional model of ocean circulation coupled to a one-box model of the atmosphere. After 100 yr, the increase in the organic matter flux is 6-30 Gt C yr-l-about twice the global new production determined by the same model for the present ocean. The removal of nutrients from surface waters of the Southern Ocean reduces the nutrient content of the near-surface and intermediate depth waters of the entire ocean, resulting in a 0.5-l.9 Gt C yr- ’ reduction of low-latitude new production. The deep circumpolar waters, enriched in nutrients by regeneration of organic matter, spread into the deep and bottom waters of the remainder of the ocean, giving an overall downward shift of nutrients from surface and intermediate to circumpolar and deep waters. The oceanic total C distribution is also shifted downward, resulting in uptake of atmospheric CO, of