The sea ice differences are calculated from the sea surface temperatures, using an approximation such that there is 100% sea ice coverage at temperatures less than -1.8C, no coverage at temperatures greater than -0.8C, and a linear fit for values in-between.  The contours represent the 0.1 (fractional coverage) contour for the modern 1961-1990 baseline (solid, red) and the 2025-2034 or 2090-2099 (dashed, blue).   For CGCM1, the actual sea ice in kg/m2 was also available.  The contours represent the approximate 0.1 m sea ice cover, but this value cannot be directly compared to the fractional sea ice coverage.  Of particular note is the dramatic melt back of sea ice in CGCM1.  Cylindrical Equidistant maps are provided as well.