Observations of superimposed ice formation at melt-onset on fast ice on Kongsfjorden, Svalbard

Abstract

Measurements of superimposed ice formation and snow properties as a function of the surface energy balance during melt-onset are presented. They were performed on fast ice on Kongsfjorden, Svalbard, between late May and early June 2002. On May 27, rapid snow melt commenced and within 5 days the snow cover initially 0.23 m thick transformed completely into 0.05-0.06 m of superimposed ice. The superimposed ice formed by both percolation of melt water to ice layers and by settling of snow between ice layers. Melt-onset was characterized by rapid changes in the total energy balance, which became positive throughout the whole day after May 27. The increased energy fluxes were mainly caused by higher incoming longwave radiation due to overcast conditions. The observations show that superimposed ice contributes significantly to sea ice mass balance.

Summer landfast sea ice desalination at Point Barrow, Alaska: Modeling and observations

“…In addition, refreezing meltwater increases heat transport to the ice. In the EL2001‐5 simulation, when snow starts to melt, we assume half of the meltwater refreezes at the ice surface, as suggested by superimposed ice fractions derived from δ 18 0 values in the uppermost ice layers by Eicken et al [2004] and direct observations of Nicolaus et al [2003]. Effectively the rate of snow loss is reduced and instead the uppermost ice layers are warmed by an equivalent amount of heat.…”

Primary producers and production in Hornsund and Kongsfjorden – comparison of two fjord systems

“…The sea ice pack, drifting with the Sørkapp Current from Storfjorden and the Barents Sea, occasionally enters Hornsund and may remain until July (Styszyńska and Kowalczyk 2007;Styszyńska and Rozwadowska 2008;Styszyńska 2009). The formation of fast ice was also a regular phenomenon in Kongsfjorden in the past, but in recent years, the fast ice has been forming only in the inner, most sheltered bay (Nicolaus et al 2003;Hop et al 2006;Gerland et al 2008;Dieckmann et al 2010;Berge et al 2015), and compared to Hornsund, it covers a much smaller part of the fjord surface (Table 2).…”

Monitoring glacier zones and snow/firn line changes in the Qinghai–Tibetan Plateau using C-band SAR imagery

“…The glacier surface can be further divided into five facies (Cuffey & Paterson, 2010): 1) dry snow facies, no melting occurs here for a whole year; 2) percolation facies, some melting occurs on the surface, and melt water percolates a certain distance into the snow before refreezing; 3) wet snow facies, in these areas, in summer, all the snow accumulated since the end of the previous summer is raised to the melting point; 4) superimposed ice facies, in these areas superimposed ice is exposed at the surface. Superimposed ice is formed when the water accumulated from surface Remote Sensing of Environment 137 (2013) [17][18][19][20][21][22][23][24][25][26][27][28][29][30] snow melt percolates downwards to the colder ice surface and refreezes (Fujita et al, 1996;Nicolaus et al, 2003); 5) ablation facies, i.e., bare ice facies, in this area the entire annual accumulation of snow melts, exposing bare ice at the surface. Very few mountain glaciers show this entire sequence.…”