Atlantic Deglacial Mg/Ca SST and d18Osw Reconstructions Carlson, A.E.; Oppo, D.W.; Came, R.E.; LeGrande, A.N.; Keigwin, L.D.; Curry, W.B. Carlson, A.E. Oppo, D.W. Came, R.E. LeGrande, A.N. Keigwin, L.D. Curry, W.B. Meridional Overturning Circulation (MOC) Sea Surface Temperature Reconstruction earth science/paleoclimate/paleoceanography (age,null,null,calendar kiloyear before present,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (magnesium/calcium,Globigerinoides ruber white,null,millimole per mole,null,paleoceanography,null,null,N,null) earth science/paleoclimate/climate reconstructions|paleoceanography (delta 18O,delta 18O|magnesium/calcium|sea water,null,per mil VSMOW,null,climate reconstructions|paleoceanography,null,null,N,G. ruber white) earth science/paleoclimate/paleoceanography (delta 18O,calcite,null,per mil,null,paleoceanography,null,null,N,null) earth science/paleoclimate/climate reconstructions|paleoceanography (sea surface temperature,magnesium/calcium,null,degree Celsius,null,climate reconstructions|paleoceanography,null,null,N,G. ruber white) earth science/paleoclimate/climate reconstructions|paleoceanography (sea surface temperature,magnesium/calcium,null,degree Celsius,null,climate reconstructions|paleoceanography,null,null,N,Globorotalia inflata) earth science/paleoclimate/paleoceanography (depth,null,null,centimeter,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (magnesium/calcium,Globorotalia inflata,null,millimole per mole,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (KNR159-36>LATITUDE -27.52>LONGITUDE -46.47) (OCE326-GGC5>LATITUDE 33.7>LONGITUDE -57.58) (KNR140-51GGC>LATITUDE 32.7833>LONGITUDE -76.2833) During the last deglaciation (ca. 21-10 ka), freshening of the North Atlantic surface likely caused reductions in Atlantic meridional overturning circulation (AMOC); the mechanisms related to AMOC recovery remain poorly understood. Here we present three new deglacial surface temperature and d18Oseawater (d18Osw) reconstructions from the western subtropical North and South Atlantic. Similarities to tropical Caribbean and western Atlantic d18Osw records suggest that a salty surface water mass accumulated in the western Atlantic from 27°S to 33°N during periods of reduced AMOC. However, d18Osw decreases led deep AMOC resumption by hundreds of years. We suggest that the northward export of salt previously trapped in the western Atlantic resulted in the early establishment of a shallow overturning circulation that eventually culminated in deep AMOC resumption, implying that AMOC may constitute a self-limiting system. STUDY NOTES: Reconstructed foraminiferal calcification temperature and d18Oseawater from three western subtropical North and South Atlantic sediment cores. Core OCE326-GGC5 is located on the Bermuda Rise, KNR140–51GGC on the Blake Outer Ridge, and KNR159–5–36GGC along the Brazilian margin. For the Blake Outer Ridge and the Brazilian margin cores, d18Ocalcite and Mg/Ca of the planktonic foraminifera Globigerinoides ruber (white) were measured. Mg/Ca was converted to calcification temperature (CT) for these two cores using a species-specific (G. ruber) core top calibration for the Atlantic basin (Dekens et al., 2002): Mg/Ca (mmol/mol) = 0.38*exp(0.09*CT) For Bermuda Rise core GGC5, d18Ocalcite and Mg/Ca of the planktonic foraminifera Globorotalia inflata were measured. A new Mg/Ca-CT calibration, following Anand et al. (2003) and Dekens et al. (2002), was developed for this core: Mg/Ca (mmol/mol) = 0.299*exp[0.09*(CT-0.61*D)] where D is the core water depth in km. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Carlson, A.E. Investigator : Oppo, D.W. Investigator : Came, R.E. Investigator : LeGrande, A.N. Investigator : Keigwin, L.D. Investigator : Curry, W.B. 2011-05-18 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/11196 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/carlson2008/carlson2008.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/carlson2008/carlson2008.xls https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/carlson2008/carlson2008.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/carlson2008/carlson2008.xls English https://www.ncdc.noaa.gov/paleo/study/11196 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/carlson2008/carlson2008.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/carlson2008/carlson2008.xls Carlson, A.E., D.W. Oppo, R.E. Came, A.N. LeGrande, L.D. Keigwin, and W.B. Curry. 2008. Subtropical Atlantic salinity variability and Atlantic meridional circulation during the last deglaciation. Geology, Vol. 36, pp. 991-994. START YEAR: 25120 cal yr BP * END YEAR: 370 cal yr BP -76.2833 -27.52 -46.47 33.7