Western Arctic Ocean temperature variability during the last 8000 years ...

• Main Authors: Farmer, Jesse Robert, Cronin, Thomas M., Vernal, Anne De, Dwyer, Gary S., Keigwin, Lloyd D., Thunell, Robert C.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Columbia University 2011
• Subjects: Paleoclimatology; Arctic; Arctic Ocean; Canada; canada basin; Foraminifera*; Sea ice
• Online Access: https://dx.doi.org/10.7916/d8gt5xxt; https://academiccommons.columbia.edu/doi/10.7916/D8GT5XXT

We reconstructed subsurface (∼200–400 m) ocean temperature and sea-ice cover in the Canada Basin, western Arctic Ocean from foraminiferal δ18O, 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. ...