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Response of the antarctic circumpolar current transport to global warming in a coupled model
Author(s) -
Bi Daohua,
Budd William F.,
Hirst Anthony C.,
Wu Xingren
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 - 10.1029/2002gl015919
Subject(s) - circumpolar star , climatology , zonal and meridional , environmental science , current (fluid) , atmospheric sciences , global warming , geology , climate change , oceanography
The transient and long‐term adjustment process of the Antarctic Circumpolar Current (ACC) in response to global warming in the CSIRO climate model is examined in an integration, which is run under increasing atmospheric CO 2 following the IPCC/IS92a scenario to stabilisation at triple the initial CO 2 concentration (3 × CO 2 ). The ACC transport through Drake Passage shows an evident strengthening along with the CO 2 increase and, in the subsequent period with stabilised 3 × CO 2 , it keeps increasing steadily after CO 2 tripling for a few centuries until a maximum (151 Sv, 17% larger than the initial state) is reached. The strengthening of the ACC transport results from the warming‐induced enhancement of the meridional density gradient in the ocean interior across the ACC: it leads to a speedup of the upper layer zonal flow which outweighs the deceleration in the underlying layer caused by the weakening of the deep overturning off Antarctica.