Western Atlantic Deglacial Paired Benthic Mg/Ca and d18O Data Came, R.E.; Curry, W.B.; Oppo, D.W.; Broccoli, A.J.; Stouffer, R.J.; Lynch-Stieglitz, J. Came, R.E. Curry, W.B. Oppo, D.W. Broccoli, A.J. Stouffer, R.J. Lynch-Stieglitz, J. Meridional Overturning Circulation (MOC) earth science/paleoclimate/paleoceanography (magnesium/calcium,benthic foraminifer,null,millimole per mole,null,paleoceanography,averaged,null,N,Hoeglundina elegans) earth science/paleoclimate/paleoceanography (age,null,null,calendar year before present,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 18O,Cibicidoides sp.,null,per mil,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (magnesium/calcium,benthic foraminifer,null,millimole per mole,null,paleoceanography,null,null,N,Hoeglundina elegans) earth science/paleoclimate/paleoceanography (notes,null,null,null,null,paleoceanography,null,null,C,Cibicidoides sp. species sampled) earth science/paleoclimate/paleoceanography (delta 18O,Cibicidoides sp.,null,per mil,null,paleoceanography,averaged,null,N,null) earth science/paleoclimate/paleoceanography (depth,null,null,centimeter,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (OCE205-2-100GGC>LATITUDE 26.066667>LONGITUDE -78.033333) (KNR166-2-31JPC>LATITUDE 24.216667>LONGITUDE -83.3) Two new records of paired benthic foraminiferal Mg/Ca and d18O from two low latitude western Atlantic sediment cores - one taken from within the Florida Current and the other from the Little Bahama Bank - provide insights into the spatial distribution of intermediate depth temperature and salinity variability during the deglaciation. During the Younger Dryas cold event, both temperature and salinity increased at the Florida Current site and decreased at the Little Bahama Bank site. The temperature increase within the Florida Current is consistent with a reduction in the strength of the northward-moving surface return flow of the Atlantic meridional overturning circulation; the temperature decrease at the Little Bahama Bank is consistent with a cooling of high latitude North Atlantic surface waters. To test the possibility that a freshening of the surface North Atlantic caused the paleoceanographic changes during the Younger Dryas, the Geophysical Fluid Dynamics Laboratory (GFDL) R30 coupled ocean-atmosphere general circulation model was forced using a North Atlantic freshwater perturbation of 0.1 Sv for a period of 100 years. The freshwater flux causes an overall reduction in the Atlantic overturning from 25 Sv to 13 Sv. However, at ~1,100 m water depth, ventilation increases, causing decreases in both temperature and salinity throughout much of the intermediate depth, open-ocean North Atlantic. At the western boundary, intermediate depth temperatures and salinities increase due to weakened overturning, and also due to an increase in runoff from the Amazon River, which causes a surface stability and a decrease in the upwelling of colder, deeper waters. STUDY NOTES: Benthic foraminiferal Mg/Ca and d18O data from two sediment cores collected in the Florida Current and the Little Bahama Bank covering the last deglacial interval. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Came, R.E. Investigator : Curry, W.B. Investigator : Oppo, D.W. Investigator : Broccoli, A.J. Investigator : Stouffer, R.J. Investigator : Lynch-Stieglitz, J. 2011-10-11 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/12215 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/came2007b/came2007b.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/came2007b/came2007b.xls https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/came2007b/came2007b.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/came2007b/came2007b.xls English https://www.ncdc.noaa.gov/paleo/study/12215 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/came2007b/came2007b.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/came2007b/came2007b.xls Came, R.E., W.B. Curry, D.W. Oppo, A.J. Broccoli, R.J. Stouffer, and J. Lynch-Stieglitz. 2007. North Atlantic Intermediate Depth Variability During the Younger Dryas: Evidence From Benthic Foraminiferal Mg/Ca and the GFDL R30 Coupled Climate Model. in Past and Future Changes of the Ocean's Meridional Overturning Circulation: Mechanisms and Impacts, Geophysical Monograph Series, edited by A. Schmittner, J. Chiang, and S. Hemming, American Geophysical Union, Washington, D.C, pp. 247-263, doi:10.1029/173GM16. START YEAR: 27784 cal yr BP * END YEAR: 613 cal yr BP -83.3 24.216667 -78.033333 26.066667