Winter sea-ice melt in the Canada Basin, Arctic Ocean

• Published in: Geophysical research letters Vol. 39; no. 3
• Main Authors: Jackson, Jennifer M., Williams, William J., Carmack, Eddy C.
• Format: Journal Article
• Language: English
• Published: Washington, DC Blackwell Publishing Ltd 01.02.2012; American Geophysical Union; John Wiley & Sons, Inc
• Subjects: Arctic Ocean; Canada Basin; Climate change; Cryosphere; Earth; Earth sciences; Earth, ocean, space; Exact sciences and technology; Ice; near-surface temperature maximum; Oceans; Physical oceanography; sea ice melt; surface mixed layer; winter storms; Canada Basin; Arctic Ocean; atmosphere; Buoy; mass balance; Entrainment (atmosphere, ocean); stratification; Summer; solar radiation; Surface temperature; storage; Ice cover; Mixed layer; Winter; sea ice; erosion; warming; Reanalysis; Halocline; Polar region; Forcing; Diffusion; heat transfer; storms
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2011GL050219

Recent warming and freshening of the Canada Basin has led to the year‐round storage of solar radiation as the near‐surface temperature maximum (NSTM). Using year‐round ocean (from ice tethered profilers and autonomous ocean flux buoys), sea‐ice (from ice mass balance buoys), and atmosphere (from NCEP/NCAR reanalysis) data from 2005–2010, we find that heat from the NSTM is entrained into the surface mixed layer (SML) during winter. Entrainment can only occur when the base of the SML reaches the top of the NSTM. If this condition is met, the surface forcing and stratification together determine whether the SML deepens into the NSTM. Heat transfer occurs by diffusion or by the erosion of the summer halocline. The average temperature of the SML warmed by as much as 0.06°C during storm events. Solar radiation began warming the SML about 1 month early during the winter of 2007–2008 and this can be explained by thin sea ice. Key Points Stored solar radiation can melt sea ice during winter Winter storms enable the release of stored solar radiation Stored solar radiation delays sea ice growth