# Southern Ocean 120KYr Nitrogen and Silicon Isotope Data #----------------------------------------------------------------------- # World Data Center for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # NOTE: Please cite Publication, and Online_Resource and date accessed when using these data. # If there is no publication information, please cite Investigators, Title, and Online_Resource and date accessed. # # # Online_Resource: http://ncdc.noaa.gov/paleo/study/17917 # # Original_Source_URL: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/robinson2014b/robinson2014e11-2.txt # # Description/Documentation lines begin with # # Data lines have no # # # Archive: Paleoceanography #-------------------- # Contribution_Date # Date: 2015-01-27 #-------------------- # Title # Study_Name: Southern Ocean 120KYr Nitrogen and Silicon Isotope Data #-------------------- # Investigators # Investigators: Robinson, R.S.; Brzezinski, M.A.; Beucher, C.P.; Horn, M.G.S.; Bedsole, P. #-------------------- # Description_and_Notes # Description: Nitrogen (d15N) and Silicon (d30Si) isotope data measured on diatoms from Southern Ocean sediment cores. #-------------------- # Publication # Authors: Rebecca S. Robinson, Mark A. Brzezinski, Charlotte P. Beucher, Matthew G. S. Horn and Patrick Bedsole # Published_Date_or_Year: 2014-12-01 # Published_Title: The changing roles of iron and vertical mixing in regulating nitrogen and silicon cycling in the Southern Ocean over the last glacial cycle # Journal_Name: Paleoceanography # Volume: 29 # Edition: # Issue: 12 # Pages: 1179-1195 # DOI: 10.1002/2014PA002686 # Online_Resource: http://www.sciencedirect.com/science/article/pii/S0012821X13007280 # Full_Citation: # Abstract: The Southern Ocean plays a critical role in the air-sea CO2 balance through biological and physical mechanisms. Vertical supply of deep waters returns nutrients and CO2 to the surface and stimulates phytoplankton growth. Photosynthesis in the Southern Ocean is limited by iron and only a fraction of the carbon and nutrients that return to the surface are consumed for potential sequestration in the deep sea. Here we present the most spatially extensive data set of silicon and nitrogen isotope measurements from diatom frustules to date to examine the controls on nutrient drawdown during the last glacial period and across the glacial termination in both the Antarctic and Subantarctic zones. The new data confirm existing views that differing silicon and nitrate consumption patterns in the Antarctic zone are likely the result, at least in part, of iron addition during the last glacial maximum (LGM). However, earlier in the glacial, a more coordinated response in the two proxy records, with both reflecting enhanced consumption during episodes of increased iron accumulation and export production, implies a different system response than observed for the LGM. A collapse of the expected equatorward gradient in silicon isotope values and contraction of the nitrogen isotope gradient during the deglaciation suggests that nutrient supply increased not only in the Antarctic Zone, but also in the Subantarctic, perhaps due to enhanced deep mixing locally. Enhanced deep water ventilation across the Southern Ocean likely increased the nutrient content of mode waters during the deglaciation. #------------------ # Funding_Agency # Funding_Agency_Name: US National Science Foundation # Grant: 00752191 #------------------ # Site_Information # Site_Name: E11-2 # Location: Ocean>Pacific Ocean>South Pacific Ocean # Country: # Northernmost_Latitude: -56.1 # Southernmost_Latitude: -56.1 # Easternmost_Longitude: -115.1 # Westernmost_Longitude: -115.1 # Elevation: m #------------------ # Data_Collection # Collection_Name: Robinson2014E11-2 # Earliest_Year: 106322 # Most_Recent_Year: 10622 # Time_Unit: Cal. Year BP # Core_Length: m # Notes: #------------------ # Chronology: # # # #---------------- # Variables # # Data variables follow that are preceded by "##" in columns one and two. # Data line variables format: Variables list, one per line, shortname-tab-longname-tab-longname components (9 components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data) # ##depth_cm depth, , , cm, , , , ,N ##age_calkaBP age, , , calendar Kyears before present, , , , ,N ##d30Sidiat delta 30Si, diatoms, , per mil v. NBS28, , , , ,N ##d30Sidiatstd delta 30Si Std Deviation, diatoms, , per mil v. NBS28, , , , ,N # #---------------- # Data: # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing Values: # # depth_cm age_calkaBP d30Sidiat d30Sidiatstd 31 10.6222 1.21 41 11.875 1.12 51 13.121 1.53 63 14.6055 0.88 73 15.827 1.17 83 17.0255 0.97 91 17.954 1.26 101 18.882 1.25 111.5 19.6113 1.16 121 20.173 1.17 131 20.716 1.4 141.5 21.2688 1.26 151.5 21.7955 1.36 171.5 22.8875 1.38 180.5 23.4038 1.47 200.5 24.6261 1.48 220.5 25.7985 1.55 240.5 27.308 1.59 270.5 29.458 1.54 310.5 32.857 1.47 359.5 38.3741 1.31 361.5 38.4811 1.18 0.16263456 371.5 38.9839 0.98 0.007071068 381.5 39.5037 0.97 0.155026879 390.5 39.9862 1.1 0.014142136 401.5 40.5975 1.02 411.5 41.1742 1.3 0.014142136 421.5 41.7727 1.316666667 0.055075705 431.5 42.3949 1.27 0.056568542 441.5 43.0391 1.08 0.105987421 450.5 43.6369 1.19 460.5 44.3402 1.25 0.049497475 470.5 45.1697 1.335 0.007071068 480.5 46.1964 1.36 0.084852814 492.5 47.581 1.12 0.056568542 502.5 48.7584 1.26 512.5 49.9172 1.275 0.148492424 522.5 51.0433 1.35 0.042426407 531.5 52.005 1.28 0.113137085 541.5 52.95 1.29 551.5 53.8071 1.14 0.098994949 561.5 54.459 1.25 0.217944947 571.5 55.0279 1.2 0.333216646 581.5 55.5611 1.11 0.070710678 591.5 56.12 1.2 0.127279221 56.9 1.05 0.06363961 611.5 57.7551 1.15 0.021213203 621.5 58.9233 1.04 0.035355339 631.5 59.9292 1.215 0.084852814 641.5 60.2236 1.3175 0.395979797 651.5 61.0721 1.04 0.06363961 62 1.15 0.070710678 681.5 63.7585 1.15 0.098994949 691.5 64.5837 1.15 0.134350288 701.5 65.3652 1.076666667 0.311126984 711.5 66.1257 1.03 0.084852814 721.5 66.8766 1.09 0.113137085 732.5 67.6732 1.106666667 0.127279221 741.5 68.2683 1 0.070710678 751.5 68.8891 1.02 0.169705627 761.5 69.4843 1.07 0.01 771.5 70.0682 1.05 0.127279221 70.7 1.185 0.233345238 790.5 71.2233 1.255 0.091923882 802.5 72.0144 1.133333333 0.155563492 812.5 72.7098 1.12 0 821.5 73.3536 1.06 0.098994949 831.5 74.0448 1.055 0.106066017 842.5 74.758 1.11 0.014142136 852.5 75.3479 1.23 0.141421356 862.5 75.8965 0.975 0.134350288 872.5 76.4073 0.82 0.070710678 881.5 76.8572 0.96 0.035355339 892.5 77.4452 1.2 902.5 78.0609 1.24 0.070710678 912.5 78.7833 1.1 0.127279221 922.5 79.6215 1.07 0.169705627 932.5 80.5901 1.09 0.084852814 942.5 81.6495 1.155 0.148492424 952.5 82.7726 1 0.106066017 962.5 83.9129 1.24 972.5 85.0162 1.035 0.233345238 982.5 86.0759 0.885 0.106066017 992.5 87.1124 0.895 0.106066017 1002.5 88.1366 0.83 0.141421356 1012.5 89.1564 1.15 0.311126984 1022.5 90.1804 1.18 1032.5 91.2199 1.17 1042.5 92.2893 1.26 0.042426407 1052.5 93.4116 1.15 1072.5 96.0324 1.21 0.141421356 1082.5 97.5209 1.02 0.049497475 1092.5 99.115 1.115 0.007071068 1102.5 100.8084 1.18 0.077781746 1112.5 102.58 1.21 0.155563492 1123.5 104.5925 1.2 0.155563492 1132.5 106.3223 1.45