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Causes of tropical Atlantic paleo‐salinity variation during periods of reduced AMOC
Author(s) -
Wan Xiuquan,
Chang Ping,
Schmidt Matthew W.
Publication year - 2010
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 - 10.1029/2009gl042013
Subject(s) - intertropical convergence zone , tropical atlantic , atlantic equatorial mode , north atlantic deep water , geology , teleconnection , climatology , oceanography , convergence zone , atlantic multidecadal oscillation , thermohaline circulation , atlantic hurricane , salinity , shutdown of thermohaline circulation , north atlantic oscillation , sea surface temperature , precipitation , tropical cyclone , geography , el niño southern oscillation , meteorology
During periods of reduced Atlantic meridional overturning circulation (AMOC) associated with a freshening of northern North Atlantic surface water, paleo proxy records indicate a corresponding surface salinity increase over the entire tropical Atlantic. Although latitudinal‐shifts in the mean position of the Atlantic Intertropical Convergence Zone (ITCZ) can explain certain features of the paleo salinity reconstructions, this mechanism does not offer an explanation for the reconstructed basin‐wide paleo‐salinity response to AMOC change. Here, we present new results from general circulation model simulations that suggest the sea surface salinity (SSS) increase in the tropical north Atlantic during periods of weakened AMOC is mainly controlled by the atmospheric response to the North Atlantic cooling, while the oceanic teleconnection contributes to increased SSS over the equatorial and south tropical Atlantic Ocean.