# North Atlantic Nitrogen and Oxygen Isotope and Mineralogy Data from Last Glacial Period #----------------------------------------------------------------------- # World Data Center for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # NOTE: Please cite original publication, online resource and date accessed when using these data, # If there is no publication information, please cite investigator, title, online resource and date accessed. # # # Online_Resource: https://www.ncdc.noaa.gov/paleo/study/15069 # # Online_Resource: http://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/straub2013/straub2013-poc.txt # # Archive: Paleoceanography #-------------------- # Contribution_Date # Date: 2013-09-16 #-------------------- # Title # Study_Name: North Atlantic Nitrogen and Oxygen Isotope and Mineralogy Data from Last Glacial Period #-------------------- # Investigators # Investigators: Straub, M.; Tremblay, M.M.; Sigman, D.M.; Studer, A.S.; Ren, H.; Toggweiler, J.R.; Haug, G.H. #-------------------- # Description_and_Notes # Description: #-------------------- # Publication # Authors: Straub, M., M.M. Tremblay, D.M. Sigman, A.S. Studer, H. Ren, J.R. Toggweiler, and G.H. Haug # Published_Date_or_Year: 2013 # Published_Title: Nutrient conditions in the subpolar North Atlantic during the last glacial period reconstructed from foraminifera-bound nitrogen isotopes # Journal_Name: Paleoceanography # Volume: 28 # Issue: # Pages: 79-90 # DOI: 10.1002/palo.20013 # Abstract: Surface nitrate concentration is a potentially useful diagnostic in reconstructing the past circulation of high-latitude North Atlantic waters. Moreover, nutrient consumption in the North Atlantic surface impacts the atmospheric concentration of carbon dioxide. To reconstruct nutrient conditions in the subpolar North Atlantic region during the last ice age, a record of foraminifera-bound d15N was measured in Neogloboquadrina pachyderma (sin.) from core V28-73 south of Iceland (57.2°N, 20.9°W). Foraminifera-bound d15N is up to 2‰ lower during the last ice age than during the Holocene, suggesting as much as ~25% less complete nitrate consumption during the former. This is consistent with stronger light limitation associated with a deeper summer surface mixed layer, perhaps related to the formation of Glacial North Atlantic Intermediate Water previously suggested to have occurred near the core site. However, three single-point maxima in d15N in the glacial section and the sharp deglacial d15N rise coincide with Heinrich event layers. This suggests that increased water column stratification during Heinrich events, presumably due to surface freshening, reduced the nutrient supply from below and led to nearly complete nitrate consumption in the summertime mixed layer. The Heinrich layers in V28-73 are not accompanied by d18O minima in either N. pachyderma (sin.) or Globigerinoides bulloides, which we tentatively attribute to extreme mixed-layer shoaling. The reconstructed subpolar North Atlantic upper water column changes—both glacial/interglacial and millennial—are inverse to those inferred for the Antarctic. # #--------------------- # Funding_Agency # Funding_Agency_Name: Swiss National Science Foundation # Grant: 200021-131886/1 #--------------------- # Funding_Agency # Funding_Agency_Name: National Science Foundation # Grant: OCE-1060947 #--------------------- # Funding_Agency # Funding_Agency_Name: NOAA Ernest F. Hollings Scholarship Program # Grant: #--------------------- # Site_Information # Site_Name: V28-73 # Location: North Atlantic Ocean # Country: # Northernmost_Latitude: 57.2 # Southernmost_Latitude: 57.2 # Easternmost_Longitude: -20.9 # Westernmost_Longitude: -20.9 # Elevation: -2063 #------------------ # Data_Collection # Core_Name: V28-73 Straub13-POC # First_Year: # Last_Year: # Time_Unit: # Core_Length: # Notes: #------------------ # Variables # # Data line variables format: shortname-tab 9 variable components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data) # Data line format: tab-delimited text, variable short name as header ## depth_cm depth,,,cm,,,,,N ## FB-d15N Foraminfera-bound delta 15N,,,per mil,,paleoceanography,,,N ## d15Nn.pachy-l delta 15N,Neogloboquadrina pachyderma left coiling,,per mil,,paleoceanography,,,N ## d15Ng.bull delta 15N,Globigerinoides bulloides,,per mil,,paleoceanography,,,N ## d15Nsed delta 15N,bulk sediment,,per mil,,paleoceanography,,,N ## d18Obulkcarb delta 18O,bulk calcium carbonate,,per mil VPDB,,paleoceanography,,,N ## dol/calc dolomite/calcite ratio,,, ,,paleoceanography,,,N ## sil/calc silicate/calcite ratio,,, ,,paleoceanography,,,N #----------------- # Data # Missing_Values: -999 depth_cm FB-d15N d15Nn.pachy-l d15Ng.bull d15Nsed d18Obulkcarb dol/calc sil/calc 5 6.96 4.02 1.63 -999 -999 -999 -999 15 6.53 4.21 0.51 3.64 -999 0.019 0.141 25 6.83 4.41 1.39 5.07 -999 -0.054 0.185 35 7.02 4.42 1.63 5.09 -999 0.054 0.546 45 7.27 4.32 2.85 5.36 3.37 -0.096 2.399 56 5.77 4.14 3.07 -999 -999 -999 -999 58 -999 -999 -999 5.59 0.70 0.419 3.234 65 5.74 3.81 3.03 5.31 2.73 0.238 0.998 75 5.31 3.84 2.64 5.38 1.71 0.131 1.093 85 5.70 3.75 2.62 5.19 2.93 0.061 1.292 93 -999 -999 -999 4.44 1.96 -0.072 0.397 95 4.91 3.32 2.49 -999 -999 -999 -999 104 6.38 3.83 2.58 5.38 0.64 0.407 3.402 115 -999 -999 -999 4.59 2.83 -0.008 0.268 125 4.56 3.36 2.24 4.65 2.81 -0.036 0.235 135 4.51 3.25 2.35 3.67 2.78 0.005 0.131 145 -999 -999 -999 4.00 2.03 -0.007 0.162 155 -999 -999 -999 3.89 1.65 0.005 0.084 165 4.54 3.30 1.83 5.39 1.09 0.078 0.637 175 -999 -999 -999 5.01 0.65 0.166 1.910 186 7.02 4.19 3.47 5.07 0.21 0.000 1.606 195 -999 -999 -999 4.99 2.90 0.011 1.471 206 5.87 3.88 2.44 5.13 1.74 0.038 1.803 216 -999 -999 -999 5.18 2.80 -0.043 0.668 225 -999 -999 -999 4.56 1.55 -0.032 1.111 235 5.77 3.41 2.25 4.00 1.86 0.016 0.566 246 5.68 3.16 2.09 -999 -999 -999 -999 255 -999 -999 -999 2.91 2.26 -0.006 0.190 266 5.34 3.52 2.51 4.02 2.30 -0.029 0.589 275 -999 -999 -999 3.55 2.49 -0.012 0.265 286 5.75 3.53 2.28 4.30 1.92 0.035 0.670 295 -999 -999 -999 4.55 1.29 -0.028 1.490 306 7.17 3.76 2.42 5.10 0.95 0.387 3.926 315 -999 -999 -999 4.35 2.79 0.002 0.250 324 -999 -999 -999 4.21 2.74 -0.076 0.383 325 6.24 3.22 2.15 -999 -999 -999 -999 335 -999 -999 -999 3.75 2.62 0.012 0.292 345 4.79 3.18 1.91 3.96 0.97 0.031 0.592