Snow dunes: A controlling factor of melt pond distribution on Arctic sea ice

The location of snow dunes over the course of the ice‐growth season 2007/08 was mapped on level landfast first‐year sea ice near Barrow, Alaska. Landfast ice formed in mid‐December and exhibited essentially homogeneous snow depths of 4–6 cm in mid‐January; by early February distinct snow dunes were observed. Despite additional snowfall and wind redistribution throughout the season, the location of the dunes was fixed by March, and these locations were highly correlated with the distribution of meltwater ponds at the beginning of June. Our observations, including ground‐based light detection and ranging system (lidar) measurements, show that melt ponds initially form in the interstices between snow dunes, and that the outline of the melt ponds is controlled by snow depth contours. The resulting preferential surface ablation of ponded ice creates the surface topography that later determines the melt pond evolution. Key Points Snow cover development was followed through winter and spring melt on sea ice The spatial snow patterns persisted throughout winter despite drifting snow Early meltpond pattern was set by snow dunes three months before melt occurred