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Modelling the climate evolution from the last interglacial to the start of the last glaciation: The role of Arctic Ocean freshwater budget
Author(s) -
Khodri M.,
Ramstein G.,
Paillard D.,
Duplessy J. C.,
Kageyama M.,
Ganopolski A.
Publication year - 2003
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 - 10.1029/2003gl017108
Subject(s) - interglacial , thermohaline circulation , glacial period , climatology , orbital forcing , climate state , climate change , geology , abrupt climate change , climate model , sea ice , oceanography , forcing (mathematics) , ocean current , environmental science , effects of global warming , global warming , paleontology
The Earth's climate has alternated between glacial and interglacial stages, but we still do not understand how the changes in insolation have been amplified by the climate system to lead to such a large climatic response. Here we use a climate model of intermediate complexity to show that the orbitally induced shift from an interglacial to a pre‐glacial climate is highly sensitive to the high northern latitudes moisture budget. Using the insolation forcing alone, the model produces a first order response of sea surface temperatures and thermohaline circulation evolution which agrees with the available geological data. Under the same gradual insolation evolution, adding a small freshwater input into the Arctic Ocean induces a rapid climate switch from an interglacial to a pre‐glacial mode. These results suggest a simple connection between orbital forcing and the thermohaline circulation through a freshwater threshold within the ocean‐atmosphere‐sea‐ice system.