# 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/robinson2014nbp9802-09.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: NBP9802-09 # Location: Ocean>Pacific Ocean>South Pacific Ocean # Country: # Northernmost_Latitude: -56.9 # Southernmost_Latitude: -56.9 # Easternmost_Longitude: -170.2 # Westernmost_Longitude: -170.2 # Elevation: m #------------------ # Data_Collection # Collection_Name: Robinson2014NBP9802-09 # Earliest_Year: 100000 # Most_Recent_Year: 9100 # 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 ##d15Ndiat delta 15N, diatoms, , per mil v. air, , , , ,N ##d30Sidiat delta 30Si, diatoms, , per mil v. NBS28, , , , ,N ##d30Sidiatstd delta 30Si Std Deviation, diatoms, , per mil v. NBS28, , , , ,N ##notes Notes-Sample Description,,,,,,,,C # #---------------- # Data: # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing Values: # # depth_cm age_calkaBP d15Ndiat d30Sidiat d30Sidiatstd notes 0 9.1 9.6 1.34 0.07 PA9802-9-1PC 0-1 cm 20 13.8 6.6 0.97 0.01 PA9802-9-1PC 20-21 cm 40 18.5 9.6 1.21 0.02 PA9802-9-1PC 40-41 cm 60 24 6.3 1.19 0.03 PA9802-9-1PC 60-61 cm 80 27.2 7.9 1.5 0.06 PA9802-9-1PC 80-81 cm 100 30.4 6.9 1.18 0.06 PA9802-9-1PC 100-101 cm 120 33.6 6.8 1.45 0.06 PA9802-9-1PC 120-121 cm 140 37.9 7.8 1.13 0.04 PA9802-9-1PC 140-141 cm 160 42.2 8.5 1.27 0.04 PA9802-9-1PC 160-161 cm 180 51.1 8.9 1.2 0.04 PA9802-9-1PC 180-181 cm 200 55.2 5.7 1.08 0.03 PA9802-9-1PC 200-201 cm 220 60 5.3 1.27 0.02 PA9802-9-1PC 220-221 cm 225 62.5 6.1 1.33 0.04 PA9802-9-1PC 225-226 cm 230 65 8.5 1.25 0.05 PA9802-9-1PC 230-231cm 235 67.5 8.3 1.15 0.03 PA9802-9-1PC 235-236 cm 240 70 6.6 1.08 0.05 PA9802-9-1PC 240-241 cm 245 72.5 7.1 1.01 0.05 PA9802-9-1PC 245-246 cm 250 75 6.8 0.89 0.04 PA9802-9-1PC 250-251 cm 255 77.5 6.1 0.87 0.06 PA9802-9-1PC 255-256 cm 260 80 6.7 0.78 0.04 PA9802-9-1PC 260-261 cm 265 82.5 7.2 1 0.06 PA9802-9-1PC 265-266 cm 270 85 5.3 0.73 0.06 PA9802-9-1PC 270-271 cm 275 87.5 8.4 0.8 0.04 PA9802-9-1PC 275-276 cm 280 90 8.5 0.92 0.03 PA9802-9-1PC 280-281 cm 285 92.5 8.1 0.87 0.08 PA9802-9-1PC 285-286 cm 290 95 9.5 0.86 0.04 PA9802-9-1PC 290-291 cm 295 97.5 6.4 1.08 0.04 PA9802-9-1PC 295-296 cm 300 100 8.7 0.96 0.09 PA9802-9-1PC 300-301 cm