# 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/robinson2014nbp9802-06.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: NBP9802-06 # Location: Ocean>Pacific Ocean>South Pacific Ocean # Country: # Northernmost_Latitude: -61.9 # Southernmost_Latitude: -61.9 # Easternmost_Longitude: -169.9 # Westernmost_Longitude: -169.9 # Elevation: m #------------------ # Data_Collection # Collection_Name: Robinson2014NBP9802-06 # Earliest_Year: 100500 # Most_Recent_Year: 1000 # 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 10 1 1.63 0 40 3.800691089 1.76 0.042426407 60 5.601382178 1.66 0.056568542 80 7.402073267 1.8 0.035355339 90 8.302418811 1.93 0.021213203 100 9.202764356 1.58 0.070710678 120 11.00345544 1.6 0.02 170 15.50518317 1.68 0.049497475 180 16.40552871 1.71 0.084852814 190 17.30587426 1.72 0.01 200 19.00474073 1.56 210 21.202938 1.37 0.021213203 250 26.94427769 1.67 0.028284271 260 28.0220488 1.43 0.06363961 270 29.09981991 1.44 280 30.17759101 1.63 0.035355339 300 32.33313323 1.56 350 49.75 1.57 0.021213203 360 51.5 1.49 0.035355339 400 58.5 1.51 0.028284271 420 62 1.55 0.042426407 430 63.75 1.51 440 65.5 1.71 0.042426407 460 69 1.69 0.007071068 470 70.75 1.67 0.056568542 500 76 1.77 0.014142136 520 79.5 1.62 0.014142136 530 81.25 1.64 0.028284271 540 83 1.45 0.167032931 550 84.75 1.44 0.021213203 560 86.5 1.43 0.01 580 90 1.56 0.049497475 600 93.5 1.66 0.014142136 630 98.75 1.63 0.056568542 640 100.5 1.59 0.120208153