FN Archimer Export Format
PT J
TI A new view on abrupt climate changes and the bipolar seesaw based on paleotemperatures from Iberian Margin sediments
BT 
AF Davtian, Nina
   Bard, Edouard
AS 1:1;2:1;
FF 1:;2:;
C1 CEREGE, Aix-Marseille University, CNRS, IRD, INRAE, Collège de France, Technopôle de l’Arbois, 13545 Aix-en-Provence, France
C2 UNIV AIX MARSEILLE, FRANCE
IF 11.1
TC 7
UR https://archimer.ifremer.fr/doc/00827/93939/100728.pdf
   https://archimer.ifremer.fr/doc/00827/93939/100729.pdf
LA English
DT Article
CR IMAGES 1-MD101
BO Marion Dufresne
DE ;bipolar seesaw;abrupt climate changes;paleotemperature;paleoceanography
AB The last glacial cycle provides the opportunity to investigate large changes in the Atlantic Meridional Overturning Circulation (AMOC) beyond the small fluctuations evidenced from direct measurements. Paleotemperature records from Greenland and the North Atlantic show an abrupt variability, called Dansgaard–Oeschger (DO) events, which is associated with abrupt changes of the AMOC. These DO events also have Southern Hemisphere counterparts via the thermal bipolar seesaw, a concept describing the meridional heat transport leading to asynchronous temperature changes between both hemispheres. However, temperature records from the North Atlantic show more pronounced DO cooling events during massive releases of icebergs known as Heinrich (H) events, contrary to ice-core–based temperature records from Greenland. Here, we present high-resolution temperature records from the Iberian Margin and a Bipolar Seesaw Index to discriminate DO cooling events with and without H events. We show that the thermal bipolar seesaw model generates synthetic Southern Hemisphere temperature records that best resemble Antarctic temperature records when using temperature records from the Iberian Margin as inputs. Our data-model comparison emphasizes the role of the thermal bipolar seesaw in the abrupt temperature variability of both hemispheres with a clear enhancement during DO cooling events with H events, implying a relationship that is more complex than a simple flip-flop between two climate states linked to a tipping point threshold. 
PY 2023
PD MAR
SO Proceedings Of The National Academy Of Sciences Of The United States Of America
SN 0027-8424
PU Proceedings of the National Academy of Sciences
VL 120
IS 12
UT 000980501000001
DI 10.1073/pnas.2209558120
ID 93939
ER

EF