Western Arctic Ocean 8KYr BWT and Sea Ice Reconstructions Farmer, J.R.; Cronin, T.M.; de Vernal, A.; Dwyer, G.S.; Keigwin, L.D.; Thunell, R.C. Farmer, J.R. Cronin, T.M. de Vernal, A. Dwyer, G.S. Keigwin, L.D. Thunell, R.C. Meridional Overturning Circulation (MOC) Sea Ice Reconstruction sea ice earth science/paleoclimate/climate reconstructions|paleoceanography (sea water temperature,magnesium/calcium,null,degree Celsius,null,climate reconstructions|paleoceanography,null,null,N,bottom water temperature from Islandiella helenae) earth science/paleoclimate/climate reconstructions|paleoceanography (sea ice cover,dinoflagellate assemblage,null,month,null,climate reconstructions|paleoceanography,null,null,N,month per year) earth science/paleoclimate/paleoceanography (age,null,null,calendar year before present,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 18O,benthic foraminifer,null,per mil VPDB,null,paleoceanography,null,null,N,Islandiella helenae) earth science/paleoclimate/paleoceanography (magnesium/calcium,ostracod,null,dimensionless,null,paleoceanography,null,null,N,null) earth science/paleoclimate/climate reconstructions|paleoceanography (sea water temperature,magnesium/calcium,null,degree Celsius,null,climate reconstructions|paleoceanography,null,null,N,bottom water temperature from Nonionella labradorica) earth science/paleoclimate/climate reconstructions|paleoceanography (sea water temperature,magnesium/calcium,null,degree Celsius,null,climate reconstructions|paleoceanography,null,null,N,bottom water temperature from Krithe glacialis) earth science/paleoclimate/paleoceanography (delta 18O,benthic foraminifer,null,per mil VPDB,null,paleoceanography,null,null,N,Nonionella labradorica) earth science/paleoclimate/paleoceanography (depth,null,null,centimeter,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (HLY0205-GGC19>LATITUDE 72.1555>LONGITUDE -155.5082) (P1-92AR-P1/B3>LATITUDE 73.7067>LONGITUDE -162.7433) We reconstructed subsurface (~200-400 m) ocean temperature and sea-ice cover in the Canada Basin, western Arctic Ocean from foraminiferal d18O, ostracode Mg/Ca ratios, and dinocyst assemblages from two sediment core records covering the last 8000 years. Results show mean temperature varied from -1 to 0.5°C and -0.5 to 1.5°C at 203 and 369 m water depths, respectively. Centennial-scale warm periods in subsurface temperature records correspond to reductions in summer sea-ice cover inferred from dinocyst assemblages around 6.5 ka, 3.5 ka, 1.8 ka and during the 15th century Common Era. These changes may reflect centennial changes in the temperature and/or strength of inflowing Atlantic Layer water originating in the eastern Arctic Ocean. By comparison, the 0.5 to 0.7°C warm temperature anomaly identified in oceanographic records from the Atlantic Layer of the Canada Basin exceeded reconstructed Atlantic Layer temperatures for the last 1200 years by about 0.5°C. STUDY NOTES: We reconstructed subsurface ocean temperature and surface sea-ice duration at centennial to submillenial-scale resolution from cores HLY0205-GGC19 and P1-92AR-P1/B3 in the Canada Basin, Arctic Ocean. Oxygen isotopic composition of benthic foraminifers and magnesium to calcium (Mg/Ca) ratios in ostracodes were used as temperature proxies, with sea-ice duration interpreted from dinocyst assemblages. Chronology for both cores was established with radiocarbon dating Data Include: 1. 14C chronology for both cores 2. GGC19 bottom water temperature from d18O of benthic foraminifer Islandiella helenae 3. GGC19 bottom water temperature from d18O of benthic foraminifer Nonion labradoricum 4. GGC19 sea-ice duration (months/year) from dinocyst assemblages 5. P1/B3 ostracode Mg/Ca and BWT, and sea-ice duration NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Farmer, J.R. Investigator : Cronin, T.M. Investigator : de Vernal, A. Investigator : Dwyer, G.S. Investigator : Keigwin, L.D. Investigator : Thunell, R.C. 2012-01-05 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/12362 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/farmer2011/farmer2011.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/farmer2011/farmer2011.xls https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/farmer2011/farmer2011.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/farmer2011/farmer2011.xls English https://www.ncdc.noaa.gov/paleo/study/12362 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/farmer2011/farmer2011.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/farmer2011/farmer2011.xls Farmer, J.R., T.M. Cronin, A. de Vernal, G.S. Dwyer, L.D. Keigwin, and R.C. Thunell. 2011. Western Arctic Ocean temperature variability during the last 8000 years. Geophysical Research Letters, Vol. 38, L24602, doi:10.1029/2011GL049714. START YEAR: 8100 cal yr BP * END YEAR: 52 cal yr BP -162.7433 72.1555 -155.5082 73.7067