# South Atlantic TN057-13PC 30 KYr Nitrogen Data #----------------------------------------------------------------------- # World Data Center for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # NOTE: Please cite original reference when using these data, # plus the Online Resource and date accessed. # # # Online_Resource: https://www.ncdc.noaa.gov/paleo/study/13545 # # Online_Resource: http://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/horn2011/horn2011.txt # # Description/Documentation lines begin with # # Data lines have no # # # Archive: Paleoceanography #-------------------- # Contribution_Date # Date: 2012-12-03 #-------------------- # Title # Study_Name: South Atlantic TN057-13PC 30 KYr Nitrogen Data #-------------------- # Investigators # Investigators: Horn, M.G.S.; Beucher, C.P.; Robinson, R.S.; Brzezinski, M.A. #-------------------- # Description_and_Notes # Description: # Bulk sedimentary and diatom-bound N isotope values for South Atlantic core TN057-13PC spanning the last 30 ky, based on previously published ages. Bulk d15N was measured by EA-IRMS. Diatom-bound d15N was measured after physical and chemical cleaning of the diatom-opal by the persulfate-denitrifier method. # #-------------------- # Publication # Authors: Matthew G. Horn, Charlotte P. Beucher, Rebecca S. Robinson, Mark A. Brzezinski # Published_Date_or_YEAR: 2011-10-15 # Published_Title: Southern ocean nitrogen and silicon dynamics during the last deglaciation # Journal_Name: Earth and Planetary Science Letters # Volume: 310 # Issue: 3-4 # Pages: 334-339 # DOI: 10.1016/j.epsl.2011.08.016 # Abstract: The reinvigoration of overturning in the Southern Ocean is hypothesized to have returned CO2 from the deep ocean to the atmosphere at the end of the last ice age. Large peaks in opal accumulation have been put forward as evidence for an increase in wind driven upwelling between 10 and 15 ka. Here, we use coupled nitrogen and silicon isotope records alongside opal accumulation rates to provide quasi-quantitative estimates of Southern Ocean nutrient supply, by upwelling, and nutrient utilization across this interval. Significant changes in the consumption of N and Si across the two opal accumulation peaks indicate major changes in both upwelling and nutrient demand. We find N and Si consumption to be relatively incomplete during peak opal accumulation at the onset of the deglaciation. This indicates that nutrient supply was significantly enhanced. The second deglacial peak in opal accumulation is associated with more complete Si consumption and variable N consumption. We suggest that this peak represents strong upwelling and more complete utilization of the available silicic acid pool. Differences between the Si and N responses during opal peaks may stem from decreasing iron availability across the glacial termination. The nutrient isotope evidence for excess nutrients during the deglaciation indicates that the high export productivity was insufficient to overcome the evasion of CO2 to the atmosphere as a result of physical circulation changes. Previous work has demonstrated that the reinvigoration of overturning circulation during the deglaciation causes a transient peak in nutrient supply to the low latitudes. This is supported by our data, which indicate that relatively high macronutrient concentrations were maintained in the Southern Ocean surface waters that are incorporated into mode waters despite high demand. # #--------------------- # Funding_Agency # Funding_Agency_Name: US National Science Foundation # Grant: OCE 00752191 #-------------------- # Site_Information # Site_Name: TN057-13PC4 # Location: Ocean>Atlantic Ocean>South Atlantic Ocean # Country: # Northernmost_Latitude: -53.1728 # Southernmost_Latitude: -53.1728 # Easternmost_Longitude: 5.1275 # Westernmost_Longitude: 5.1275 # Elevation: -2848 m #------------------ # Data_Collection # Core_Name: TN057-13PC4Horn2011 # First_Year: 29320 # Last_Year: 0 # Time_Unit: Calendar Years before present # Core_Length: 0.904 m # Notes: #------------------ # Chronology # # See Anderson et al. 2009, Science, Vol. 323, pp. 1443, 13 March 2009. DOI: 10.1126/science.1167441 # http://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2009/anderson2009.txt # #------------------ # Variables # # End Description/Documentation (lines begin with #) # Data lines follow (have no #) # Data line variables format: Variables list, one per line, shortname-tab-longname-tab-longname components (9 components: material, error, units, anomaly, period, 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), , , cm, , , , , N ## age_calKaBP Age (calendar K years BP), , ,cal Ky BP, , , , , N ## Nconc-opal N content of Opal, , ,umol N/g Opal, , , , , N ## d15Ndiatom delta 15N (diatom-bound organic matter), , ,per mil, , , , , N ## d15N delta N15, , ,per mil, , , , , N ## Nconc N content of Bulk sediment, , ,umol N/g, , , , , N #------------------------ # Data: # Missing Value: NA depth_cm age_calKaBP Nconc-opal d15Ndiatom d15N Nconc 0 0.00 12.61 10.49 4.38 30.67 26 0.81 13.00 9.35 4.46 27.63 50 1.28 12.76 10.06 4.65 27.93 75 1.86 12.94 10.06 5.74 27.79 97 2.47 12.80 10.04 5.11 28.17 125 3.24 10.76 9.87 5.46 27.45 152 3.98 12.06 10.10 5.29 29.69 173 4.56 13.60 10.16 6.06 31.24 202 5.36 14.09 10.14 5.60 30.20 225 5.99 16.18 10.05 4.35 36.19 252 6.73 10.45 10.32 4.35 33.66 276 7.12 11.59 9.88 4.60 39.57 305 7.53 12.50 9.99 4.92 36.44 329 7.86 12.72 10.34 4.81 35.22 344 8.07 11.34 10.10 5.27 32.78 372 8.46 11.58 10.18 5.21 32.53 398 8.83 12.73 10.73 4.39 31.35 424 9.19 13.72 9.84 4.46 31.41 448 9.52 14.81 9.61 4.91 30.07 471 9.54 12.94 10.29 4.74 30.88 494 9.85 13.60 10.76 4.96 22.32 512 10.11 14.24 10.15 4.44 25.96 533 10.40 4.23 32.30 552 10.74 12.74 10.67 4.24 23.64 572 11.12 15.53 9.96 4.94 25.84 590 11.46 12.29 10.55 4.42 19.87 608 11.80 14.01 9.07 4.70 19.89 628 12.18 14.46 10.13 4.39 22.44 648 12.56 17.83 9.85 5.08 25.42 668 12.94 16.87 9.80 5.04 30.15 691 13.37 17.41 8.73 4.23 29.07 711 13.74 16.01 9.81 4.83 31.15 721 13.93 16.98 9.29 5.01 33.69 730 14.10 15.66 9.81 4.74 29.72 743 14.50 18.59 9.32 4.88 29.34 748 14.95 19.09 9.56 4.55 28.02 754 15.50 18.46 9.72 4.21 34.51 759 15.97 20.09 8.61 4.27 35.22 763 16.33 19.08 9.36 4.93 34.79 770 16.98 14.89 9.79 5.47 38.56 775 17.44 16.12 11.00 5.23 41.13 780 17.90 14.54 10.81 6.28 42.30 785 18.36 13.67 10.88 4.74 42.89 789 18.73 14.05 10.97 5.30 47.74 794 19.19 14.89 10.29 4.95 55.33 802 19.92 13.97 10.01 5.32 47.97 812 20.85 12.82 9.27 5.79 37.14 824 21.95 11.71 9.25 5.02 34.56 835 22.97 12.46 4.85 35.86 846 23.98 13.52 8.95 4.85 29.96 855 24.81 14.00 8.95 4.62 33.55 865 25.73 14.42 8.97 5.20 34.45 875 26.65 14.99 9.37 4.53 35.27 886 27.66 13.79 9.69 4.92 37.54 895 28.49 15.41 8.06 4.30 41.58 904 29.32 17.80 8.21 3.86 40.43