The Southern Ocean waters reflect the sunlight specularly towards the satellite.
Evolution of the natural RGB, based on channels 3, 2 and 1 from Meteosat-10 during the northern hemisphere (NH) winter solstice. This is a rare case of Meteosat sunglint at polar latitudes. A similar effect is observed on calm waters in the Arctic region in June during the NH summer solstice.
Symmetry suggests similar features east of Greenwich, however, these were not found. The animation, from 21 December 22:27 UTC–22 December 00:27 UTC and the comparison, below identifies the brightest sunglint occurring on icy waters.
Download animation, 21 December 22:27 UTC–22 December 2013 00:27 UTC