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Effect of the Atlantic Multidecadal Variability on the Global Monsoon
Author(s) -
Monerie PaulArthur,
Robson Jon,
Dong Buwen,
Hodson Dan L. R.,
Klingaman Nicholas P.
Publication year - 2019
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 - 10.1029/2018gl080903
Subject(s) - climatology , monsoon , precipitation , extratropical cyclone , sea surface temperature , environmental science , atmospheric circulation , atlantic multidecadal oscillation , oceanography , atmospheric sciences , geology , geography , meteorology
We assess the effect of the Atlantic multidecadal variability (AMV) on the global monsoon using idealized simulations. Warm AMV phases are associated with a significant strengthening of monsoon precipitation over Northern Africa and India, and anomalously weak monsoon precipitation over South America. Changes in monsoon precipitation are mediated by a change in atmospheric dynamics, primarily associated with a shift in the circulation related to both an enhanced interhemispheric thermal contrast and the remote impact of AMV on the Pacific Ocean, through changes in the Walker circulation. In contrast, the thermodynamic changes are less important. Further experiments show that the impact of AMV is largely due to the tropical component of the sea surface temperature anomalies. However, the extratropical Atlantic also plays a role, especially for northern Africa. Finally, we show that the effect of AMV on monsoons is not linearly related to the magnitude of warming.