The Influence of Snow Depth Distribution and Surface Topography on Melt Pond Evolution

Abstract:

The seasonal evolution of melt ponds has been well-documented on multiyear and landfast first-year sea ice, but is critically lacking on drifting, first-year sea ice, which is becoming increasingly prevalent in the Arctic. Using 1-meter resolution panchromatic satellite imagery paired with airborne and in situ data, we evaluated melt pond evolution for an entire melt season on drifting first-year and multiyear sea ice near the 2011 Applied Physics Laboratory Ice Station (APLIS) site in the Beaufort and Chukchi seas. A new algorithm was developed to classify the imagery into sea ice, thin ice, melt pond, and open water classes on two contrasting ice types: first-year and multiyear sea ice. Surprisingly, melt ponds formed ~3 weeks earlier on multiyear ice. Both ice types had comparable mean snow depths, but multiyear ice had 0 - 5-cm deep snow covering ~37% of its surveyed area, which may have facilitated earlier melt due to its relatively low surface albedo. The observed difference in the pace of melt between first-year and multiyear ice was likely a result of their surface topographies. First-year sea ice, which was predominantly undeformed, exhibited uniform melt pond formation, growth, and drainage while melt pond evolution on multiyear sea ice was spatially and temporally non-uniform. Maximum pond fractions were 53 ± 3% and 38 ± 3% on first-year and multiyear ice, respectively. These results reveal considerable differences in pond evolution between ice types, and underscore the importance of snow depth distributions and surface topography in the timing and progression of melt pond formation.