FN Archimer Export Format
PT J
TI Parallelisms between sea surface temperature changes in the western tropical Atlantic (Guiana Basin) and high latitude climate signals over the last 140 000 years
BT 
AF RAMA-CORREDOR, O.
   MARTRAT, B.
   GRIMALT, J. O.
   LOPEZ-OTALVARO, G. E.
   FLORES, J. A.
   SIERRO, F.
AS 1:1;2:1;3:1;4:2;5:2;6:2;
FF 1:;2:;3:;4:;5:;6:;
C1 CSIC, IDAEA, Dept Environm Chem, ES-08034 Barcelona, Catalonia, Spain.
   Univ Salamanca, Dept Geol, E-37008 Salamanca, Spain.
C2 CSIC, SPAIN
   UNIV SALAMANCA, SPAIN
IN DOAJ
IF 3.638
TC 18
UR https://archimer.ifremer.fr/doc/00296/40765/39760.pdf
   https://archimer.ifremer.fr/doc/00296/40765/39761.pdf
   https://archimer.ifremer.fr/doc/00296/40765/48239.pdf
LA English
DT Article
CR MD 132 / P.I.C.A.S.S.O.-IMAGES11
BO Marion Dufresne
AB Sea surface temperatures (SST) in the Guiana Basin over the last 140 ka were obtained by measuring the C37 alkenone unsaturation index Uk'37 in the sediment core MD03-2616 (7° N, 53° W). The resulting data set is unique in the western tropical Atlantic region for this period. The SSTs range from 25.1 to 28.9 °C, i.e. glacial–interglacial amplitude of 3.8 °C, which is in the range of change of other tropical areas.  During the last two interglacial stages (marine isotope stages; MIS1 and MIS5e) and warm long interstadials (MIS5d-a), a rapid transmission of climate variability from Arctic–tropical latitudes is recorded. During these periods, the MD03-2616 SSTs show a conspicuous parallelism with temperature changes observed in Greenland and SST records of North Atlantic mid-latitude cores (Iberian Margin 38° N, Martrat et al., 2007).  The last deglaciation in the Guiana Basin is particularly revealing. MIS2 stands out as the coldest period of the interval analysed. The events recorded in Guiana parallel northern latitude events such as the Bølling–Allerød warming and the Younger Dryas cooling which ensued. These oscillations were previously documented in the δ18O of the Sajama tropical ice core (Bolivia) and are present in Guiana, with rates of ca. 6 °C ka−1 and changes of over 2 °C.  During the glacial interval, significant abrupt variability is observed, e.g. oscillations of 0.5–1.2 °C during MIS3, which is about 30 % of the maximum glacial–interglacial SST change. In the MD03-2616 record, it is possible to unambiguously identify either the Dansgaard–Oeschger oscillations described in northern latitudes or the SST drops associated with the Heinrich events characteristic of North Atlantic records. Although these events form the background of the climate variability observed, what truly shapes SSTs in the Guiana Basin is a long-term tropical response to precessional changes, which is modulated in the opposite way to Northern Hemisphere variability. This lack of synchrony is consistent with other tropical records in locations to the north or south of the Guiana Basin and evidences an Arctic–tropical decoupling when a substantial reduction in the Atlantic meridional overturning circulation (AMOC) takes place.
PY 2015
SO Climate Of The Past
SN 1814-9324
PU Copernicus Gesellschaft Mbh
VL 11
IS 10
UT 000364324600002
BP 1297
EP 1311
DI 10.5194/cp-11-1297-2015
ID 40765
ER

EF