FN Archimer Export Format
PT J
TI Florida Straits deglacial temperature and salinity change: Implications for tropical hydrologic cycle variability during the Younger Dryas
BT 
AF SCHMIDT, Matthew W.
   LYNCH-STIEGLITZ, Jean
AS 1:1;2:2;
FF 1:;2:;
C1 Texas A&M Univ, Dept Oceanog, College Stn, TX 77843 USA.
   Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30307 USA.
C2 UNIV TEXAS A&M HOUSTON, USA
   GEORGIA INST TECHNOL, USA
IF 3.357
TC 49
UR https://archimer.ifremer.fr/doc/00227/33802/32514.pdf
   https://archimer.ifremer.fr/doc/00227/33802/32515.pdf
LA English
DT Article
CR MD 127 / PAGE
BO Marion Dufresne
AB The prevailing paradigm of abrupt climate change holds that rapid shifts associated with the most extreme climate swings of the last glacial cycle were forced by changes in the strength and northward extension of Atlantic Meridional Overturning Circulation (AMOC), resulting in an abrupt reorganization of atmospheric circulation patterns with global teleconnections. To determine the timing of tropical Atlantic atmospheric circulation changes over the past 21 ka BP, we reconstruct high resolution sea surface temperature and delta O-18(SW) (a proxy for surface salinity) records based on Mg/Ca ratios and oxygen isotope measurements in the planktonic foraminifera Globigerinoides ruber from a sediment core located on the western margin of the Florida Straits. As a proxy for meltwater discharge influence on Florida Straits surface water salinity, we also measured Ba/Ca ratios in G. ruber from the same core. Results show that riverine influence on Florida Straits surface water started by 17.2 ka BP and ended by 13.6 ka BP, 600 years before the start of the Younger Dryas (YD) cold interval. The initiation of the YD is marked by an abrupt increase in Florida Straits delta O-18(SW) values, indicating a shift to elevated sea surface salinity occurring in 130 years, most likely resulting from increased regional aridity and/or reduced precipitation. In order to resolve the timing of tropical atmospheric circulation change relative to AMOC variability across this transition, we compare the timing of surface water changes to a recently published record of Florida Current variability in the same core reconstructed from benthic oxygen isotope measurements. We find synchronous changes in atmospheric and ocean circulation on the transition into the YD, consistent with an abrupt reduction in AMOC as the driver of tropical Atlantic atmospheric circulation change at this time.
PY 2011
PD OCT
SO Paleoceanography
SN 0883-8305
PU Amer Geophysical Union
VL 26
IS 4
UT 000296160400001
DI 10.1029/2011PA002157
ID 33802
ER

EF