# Tropical Atlantic Isotope, Chemistry and SST Data for the Last 27,000 Years #----------------------------------------------------------------------- # World Data Center for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # NOTE: Please cite original publication, online resource and date accessed when using this data. # If there is no publication information, please cite Investigator, title, online resource and date accessed. # # Online_Resource: http://www.hurricane.ncdc.noaa.gov/pls/paleox/f?p=519:1:::::P1_STUDY_ID:16380 # # Original_Source_URL: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/arbuszewski2013/arbuszewski2013-vm25-59.txt # # Archive: Paleoceanography # #-------------------------------- # Contribution_Date # Date: 2014-04-24 #-------------------------------- # Title: Tropical Atlantic Isotope, Chemistry and SST Data for the Last 27,000 Years #-------------------------------- # Investigators: Arbuszewski, J.A.; deMenocal, P.B.; Cleroux, C.; Bradtmiller, L.; Mix, A.C. #-------------------- # Description and Notes: # Description: 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. # #-------------------- # Publication # Authors: Arbuszewski, J.A., P.B. deMenocal, C. Cleroux, L. Bradtmiller, and A. Mix # Journal_Name: Nature Geoscience # Published_Title: Meridional shifts of the Atlantic intertropical convergence zone since the Last Glacial Maximum # Published_Date_or_Year: 2013 # Volume: 6 # Pages: 959-962 # DOI: 10.1038/ngeo1961 # Abstract: 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. #-------------------------------- # Funding_Agency: # Funding_Agency_Name: US National Science Foundation # Grant: OCE-0927247 #-------------------------------- # Site Information: # Site_Name: VM25-59 # Location: Atlantic Ocean # Northernmost_Latitude: 1.367 # Southernmost_Latitude: 1.367 # Easternmost_Longitude: -33.483 # Westernmost_Longitude: -33.483 # Elevation: -3824 #-------------------------------- # Data Collection # Collection_Name: VM25-59 Arb13 # Oldest_Year: 25426 # Most_Recent_Year: 1890 # Time_Unit: cal yrBP # Core_Length: # Notes: #-------------------------------- # Chronology # VM25-59 # depth (cm) 14C Age standard deviation age (cal years BP) measurement type material source # 15 5785 35 6201.5 14C G. ruber (white) this study # 32.5 10370 35 12238 14C G. ruber (white) this study # 62.5 18740 80 22321.5 14C G. ruber (white) this study # 72.5 22380 110 26461 14C G. ruber (white) this study # 95 27040 190 31557 14C G. ruber (white) this study # #-------------------------------- # Variables # # Data variables follow (have double marker- "##") # Data line variables format: Variables list, one per line, shortname-tab-nine components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data) ## depth_cm depth ,,,cm,,,,,N ## age_calyrBP age,,,cal yr BP,,,,,N ## Mg/Ca-g.rub-w Magnesium Calcium ratio,G. ruber white,,mmol/mol,,paleoceanography,,,N ## d18Og.sac-rubc delta 18O,Globigerinoides sacculifer,,per mil VPDB,,paleoceanography,,G. ruber corrected,N ## d18Og.rub-w-iv delta 18O,Globigerinoides ruber white,,per mil VPDB,,paleoceanography,ice volume corrected,,N ## sst-Mg/Ca-grubw.d sea surface temperature, Magnesium Calcium ratio G. ruber white,,degrees Celsius,,paleoceanography,using Dekens et al.(2002),,N ## sst-grubw-calc.a sea surface temperature,Magnesium Calcium ratio G. ruber white,,degrees Celsius,,paleoceanography,using salinity and DeltaCO32- from Arbuszewski et al.(2010),,N ## d18Osw-g.rubw delta 18O,seawater,,per mil SMOW,,paleoceanography,,from Bemis et al.(1998),N ## d18Osw-ivc-g.rubw delta 18O,seawater,,per mil SMOW,,paleoceanography,ice volume corrected,from Bemis et al.(1998),N ## sal-grubw.a salinity,G. ruber white,,ppt,,paleoceanography,calculated using Arbuszewski et al.(2010),,N # Data: # Missing Value: -999 depth_cm age_calyrBP Mg/Ca-g.rub-w d18Og.sac-rubc d18Og.rub-w-iv sst-Mg/Ca.d sst-calc.a d18Osw-g.rubw d18Osw-ivc-g.rubw sal-grubw.a 2.5 1890 4.04 -1.83 -1.89 28.59 27.05 1.29 1.24 35.92 5 2752 3.87 -1.92 -1.98 28.12 27.19 1.10 1.04 35.78 7.5 3614 4.01 -1.75 -1.82 28.51 26.80 1.36 1.29 35.94 10 4477 4.20 -1.63 -1.71 29.02 26.62 1.58 1.50 36.10 12.5 5339 4.27 -1.78 -1.86 29.21 27.23 1.47 1.39 36.04 15 6201 3.97 -1.61 -1.69 28.41 26.33 1.47 1.39 36.00 17.5 7064 3.97 -1.13 -1.23 28.39 24.73 1.95 1.85 36.27 20 7926 4.09 -1.31 -1.44 28.74 25.58 1.84 1.72 36.21 22.5 8789 4.31 -1.17 -1.34 29.32 25.49 2.10 1.94 36.37 25 9651 4.24 -1.12 -1.34 29.13 25.42 2.12 1.89 36.33 27.5 10513 4.09 -999.00 -999.00 28.74 -999.00 -999.00 -999.00 -999.00 30 11376 4.33 -0.9 -1.24 29.37 25.17 2.38 2.05 36.44 32.5 12238 3.99 -0.61 -1.02 28.46 24.06 2.49 2.07 36.40 35 13078 3.79 -999.00 -999.00 27.88 -999.00 -999.00 -999.00 -999.00 37.5 13919 3.37 -0.66 -1.23 26.57 23.99 2.04 1.47 35.94 40 14759 3.04 -0.4 -1.08 25.45 23.01 2.07 1.38 35.83 42.5 15599 3.13 -0.34 -1.13 25.76 23.30 2.19 1.40 35.86 45 16439 3.02 -0.35 -1.19 25.38 23.34 2.10 1.26 35.76 47.5 17280 2.94 -0.09 -0.96 25.07 22.42 2.30 1.43 35.84 50 18120 2.59 -0.37 -1.26 23.67 22.88 1.73 0.83 35.41 52.5 18960 2.73 -0.18 -1.11 24.24 22.59 2.04 1.11 35.60 55 19801 2.58 -0.47 -1.44 23.63 23.47 1.62 0.65 35.30 57.5 20641 2.52 -0.24 -1.23 23.37 22.63 1.80 0.81 35.38 60 21481 2.48 -0.15 -1.12 23.19 22.20 1.85 0.88 35.41 67.5 24391 2.81 -0.36 -1.21 24.58 23.08 1.93 1.08 35.60 70 25426 2.81 -0.32 -1.06 24.58 22.55 1.97 1.23 35.69