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Sensitivity of the thermohaline circulation to increased CO 2 and lowered topography
Author(s) -
Vavrus Steve,
Kutzbach John E.
Publication year - 2002
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2002gl014814
Subject(s) - thermohaline circulation , geology , plateau (mathematics) , atmosphere (unit) , climatology , atmospheric circulation , convection , elevation (ballistics) , atmospheric sciences , oceanography , environmental science , meteorology , mathematical analysis , physics , geometry , mathematics
We use an asynchronously coupled atmosphere‐ocean model to examine the response of the oceanic thermohaline circulation (THC) to increased atmospheric CO 2 and lowered topography. In Experiment “3CO2”, CO 2 was tripled relative to modern with no accompanying reductions in topography. In Experiment “LT3CO2”, CO 2 was also tripled, in combination with lowered topography (“LT”), with elevation reductions for all major mountain ranges and ice sheets to approximate paleoclimatic conditions prior to recent major uplift and CO 2 draw down (before 10 Ma). Although the THC changes from the control simulation by at least 25% in both experiments, the THC weakens with higher CO 2 alone but strengthens with higher CO 2 and lowered topography. The stronger THC in LT3CO2 is caused by the removal of the Tibetan Plateau and the Greenland Ice Sheet. Lowering these features alters the atmospheric circulation to promote Arctic air flow over the convective North Atlantic, thereby destabilizing the upper ocean.