[1] Environm Canada, Climate Res Div, Toronto, ON, Canada
[2] Northumbria Univ, Dept Geog, Newcastle Upon Tyne NE1 8ST, Tyne & Wear, England
[3] Univ Alberta, Dept Earth & Atmospher Sci, Edmonton, AB, Canada
[4] York Univ, Dept Earth & Space Sci & Engn, Toronto, ON M3J 2R7, Canada
[5] NASA, Goddard Space Flight Ctr, Hydrospher & Biospher Sci Lab, Greenbelt, MD 20771 USA
[6] Engn Res & Dev Ctr, Cold Reg Res & Engn Lab, Hanover, NH USA