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The Impact of the AMOC Resumption in the Western South Atlantic Thermocline at the Onset of the Last Interglacial
Author(s) -
Santos Thiago P.,
Lessa Douglas O.,
Venancio Igor M.,
Chiessi Cristiano M.,
Mulitza Stefan,
Kuhnert Henning,
Albuquerque Ana Luiza S.
Publication year - 2017
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 - 10.1002/2017gl074457
Subject(s) - interglacial , thermocline , geology , deglaciation , glacial period , oceanography , foraminifera , north atlantic deep water , climatology , holocene , subtropics , thermohaline circulation , paleontology , benthic zone , fishery , biology
After glacial terminations, large amounts of heat and salt were transferred from low to high latitudes, which is a crucial phenomenon for the reestablishment of the Atlantic Meridional Overturning Circulation (AMOC). However, how different glacial terminations evolved in the (sub)tropics is still poorly documented. Here we use foraminifera oxygen (δ 18 O) and carbon (δ 13 C) stable isotopes to show that the North Atlantic heat piracy, following the AMOC resumption at the early Last Interglacial, affected the thermocline δ 18 O levels of the subtropical western South Atlantic. Because of the cooling imposed by this process, glacial δ 18 O persisted in the thermocline for ~7 kyr after the onset of the Last Interglacial, dampening the effect of sea level rise usually imprinted on foraminifera δ 18 O during terminations. Faunal composition and δ 13 C also suggest the existence of a colder and thicker South Atlantic Central Water coeval with the AMOC recovery. This process apparently did not occur during the last deglaciation.