Tropical Atlantic Isotope, Chemistry and SST Data for the Last 27,000 Years Arbuszewski, J.A.; deMenocal, P.B.; Cleroux, C.; Bradtmiller, L.I.; Mix, A.C. Arbuszewski, J.A. deMenocal, P.B. Cleroux, C. Bradtmiller, L.I. Mix, A.C. Intertropical Convergence Zone (ITCZ) Sea Surface Temperature Reconstruction earth science/paleoclimate/climate reconstructions|paleoceanography (delta 18O,delta 18O|magnesium/calcium|sea water,null,per mil SMOW,null,climate reconstructions|paleoceanography,null,null,N,from Bemis et al.(1998)) earth science/paleoclimate/climate reconstructions|paleoceanography (sea surface temperature,magnesium/calcium,null,degree Celsius,null,climate reconstructions|paleoceanography,null,null,N,using Dekens et al.(2002); G. ruber white) 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 SMOW,null,climate reconstructions|paleoceanography,corrected,null,N,from Bemis et al.(1998); corrected for ice volume) earth science/paleoclimate/paleoceanography (age,null,null,calendar year before present,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 18O,Globigerinoides ruber white,null,per mil VPDB,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,using salinity and DeltaCO32- from Arbuszewski et al.(2010); G. ruber white) earth science/paleoclimate/paleoceanography (delta 18O,Globigerinoides ruber white,null,per mil VPDB,null,paleoceanography,corrected,null,N,ice volume corrected) earth science/paleoclimate/climate reconstructions|paleoceanography (salinity,delta 18O|magnesium/calcium|sea surface,null,parts per thousand,null,climate reconstructions|paleoceanography,null,null,N,calculated using Arbuszewski et al.(2010)) earth science/paleoclimate/paleoceanography (depth,null,null,centimeter,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (VM25-59>LATITUDE 1.367>LONGITUDE -33.483) (RC24-08>LATITUDE -1.3366>LONGITUDE -11.9) (RC24-11>LATITUDE -2.18>LONGITUDE -11.25) (VM30-40>LATITUDE -.2>LONGITUDE -23.15) The intertropical convergence zone is a near-equatorial band of intense rainfall and convection. Over the modern Atlantic Ocean, its annual average position is approximately 5°N, and it is associated with low sea surface salinity and high surface temperatures. This average position has varied since the Last Glacial Maximum, in response to changing climate boundary conditions. The nature of this variation is less clear, with suggestions that the intertropical convergence zone migrated north-south away from the colder hemisphere or that it contracted and expanded symmetrically around its present position. Here we use paired Mg/Ca and d18O measurements of planktonic foraminifera for a transect of ocean sediment cores to reconstruct past changes in tropical surface ocean temperature and salinity in the Atlantic Ocean over the past 25,000 years. We show that the low-salinity, high-temperature surface waters associated with the intertropical convergence zone migrated southward of ! their present position during the Last Glacial Maximum, when the Northern Hemisphere cooled, and northward during the warmer early Holocene, by about ±7° degrees of latitude. Our evidence suggests that the intertropical convergence zone moved latitudinally over the ocean, rather than expanding or contracting. We conclude that the marine intertropical convergence zone has migrated significantly away from its present position owing to external climate forcing during the past 25,000 years. STUDY NOTES: Ice volume corrections to shell δ18O values are made using sea level curve of Waelbroeck et al. 2002. Note Mg/Ca ratios represent an average where replicate analyses were performed. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Arbuszewski, J.A. Investigator : deMenocal, P.B. Investigator : Cleroux, C. Investigator : Bradtmiller, L.I. Investigator : Mix, A.C. 2014-04-28 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/16380 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/arbuszewski2013/arbuszewski2013-vm25-59.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/arbuszewski2013/arbuszewski2013-rc24-11.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/arbuszewski2013/arbuszewski2013-rc24-08.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/arbuszewski2013/arbuszewski2013-vm30-40.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/arbuszewski2013/arbuszewski2013-vm25-59.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/arbuszewski2013/arbuszewski2013-rc24-11.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/arbuszewski2013/arbuszewski2013-rc24-08.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/arbuszewski2013/arbuszewski2013-vm30-40.txt English https://www.ncdc.noaa.gov/paleo/study/16380 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/arbuszewski2013/arbuszewski2013-vm25-59.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/arbuszewski2013/arbuszewski2013-rc24-11.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/arbuszewski2013/arbuszewski2013-rc24-08.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/arbuszewski2013/arbuszewski2013-vm30-40.txt Arbuszewski, J.A., P.B. deMenocal, C. Cleroux, L. Bradtmiller, and A. Mix2013Meridional shifts of the Atlantic intertropical convergence zone since the Last Glacial MaximumNature Geoscience6959-96210.1038/ngeo1961 START YEAR: 27667 cal yr BP * END YEAR: 1890 cal yr BP -33.483 -2.18 -11.25 1.367