We used modern analog technique applied to Antarctic diatoms to quanti
tatively reconstruct seasonal sea-ice extent at the Last Glacial Maxim
um. Winter maximum sea-ice limit occurred around 48 degrees S in the A
tlantic and western Indian sectors, around 55 degrees S in the eastern
Indian and western Pacific sectors, and around 58-60 degrees S in the
eastern Pacific sector of the Southern Ocean. Summer maximum sea-ice
extents during the last ice age and today are similar, which contradic
ts CLIMAP's findings. This implies a reduced summer albedo feedback of
the Southern Hemisphere and a greater transfer of heat and moisture f
rom the ocean to the atmosphere than shown by previous qualitative stu
dies.