Anatomy of a late spring snowfall on sea ice

Spring melt initiation is a critical process for Arctic sea ice. Melting conditions decrease surface albedo at a time of high insolation, triggering powerful albedo feedback. Weather events during melt initiation, such as new snowfalls, can stop or reverse the albedo decline, however. Here we present field observations of such a snow event and demonstrate its enduring impact through summer. Snow fell 3-6 June 2014 in the Chukchi Sea, halting melt onset. The snow not only raised albedo but also provided a significant negative latent heat flux, averaging -51Wm(-2) from 3 to 6 June. The snowfall delayed sustained melt by 11days, creating cascading impacts on surface energy balance that totaled some 135MJ/m(2) by mid-August. The findings highlight the sensitivity of sea ice conditions on seasonal time scales to melt initiation processes.