@Article{BallalaiSLVCJKTCL:2019:TrSpAg,
author = "Ballalai, Jo{\~a}o and Santos, Thiago Pereira dos and Lessa,
Douglas Villela de Oliveira and Venancio, Igor Martins and
Chiessi, Cristiano M. and Johnstone, Heather H. and Kuhnert,
Henning and Toledo, Felipe Antonio de Lima and Costa, Karen B. and
Luiza, Albuquerque Ana",
affiliation = "{Universidade Federal Fluminense (UFF)} and {Universidade Federal
Fluminense (UFF)} and {Universidade Federal Fluminense (UFF)} and
{Instituto Nacional de Pesquisas Espaciais (INPE)} and
{Universidade de S{\~a}o Paulo (USP)} and {University of Bremen}
and {University of Bremen} and {Universidade de S{\~a}o Paulo
(USP)} and {Universidade de S{\~a}o Paulo (USP)} and
{Universidade Federal Fluminense (UFF)}",
title = "Tracking the spread of Agulhas Leakage to the western South
Atlantic and its northward transmission during the last
interglacial",
journal = "Paleoceanography and Paleoclimatology",
year = "2019",
volume = "34",
number = "11",
pages = "1744--1760",
month = "Nov.",
keywords = "Termination II, Brazil Current, Agulhas rings, Subtropical gyre,
Atlantic Meridional Overturning Circulation.",
abstract = "Intensifications of the Agulhas Leakage (AL) during glacial
Terminations have long been proposed as a necessary mechanism to
return the Atlantic Meridional Overturning Circulation (AMOC) to
its interglacial mode. However, the lack of records showing the
downstream evolution of the AL signal and the large temporal
differences between AL intensification and the resumption of
deep-water convection cast doubt on the importance of this
mechanism to the overturning. Here, we analyze a combination of
new and previously published data related to Mg/Ca-derived
temperatures and ice-volume-corrected seawater \δ18O
(\δ18OIVC-SW as a proxy for ocean salinity) that demonstrate
the propagation of the AL signal via surface and thermocline
waters to the western South Atlantic (Santos Basin) during glacial
Termination II and the early Last Interglacial. The saline AL
waters were temporarily stored in the upper subtropical South
Atlantic until two abrupt freshening steps indicate their release
into the North Atlantic via the surface and thermocline waters at
ca. 129 and 123 ka BP, respectively. Considering age
uncertainties, these two steps are coeval with the resumption of
convection in the Labrador and Nordic Seas during the Last
Interglacial. We propose a mechanism in which both a strong AL and
a favorable ocean-atmosphere configuration in the tropical
Atlantic were required to allow the flux of AL waters into the
North Atlantic, where they then contributed to pushing the AMOC
during the Last Interglacial. Our results provide a framework that
connects AL strengthening to the AMOC intensifications that follow
glaciations.",
doi = "10.1029/2019PA003653",
url = "http://dx.doi.org/10.1029/2019PA003653",
issn = "2572-4517",
language = "en",
targetfile = "ballalai_tracking.pdf",
urlaccessdate = "28 mar. 2024"
}