Energy balance of the intertidal zone of Western Hudson bay II: Ice‐dominated periods and seasonal patterns

Abstract

Abstract This study treats the energy balance during fast‐ice and floating‐ice conditions and examines overall seasonal patterns. The rate of ablation of the fast ice was controlled equally by net radiation and air temperature. The ratio of net/solar radiation increased 2.5 times during the ablation period owing to the decrease in ice albedo. Air temperature in the ablation zone was up to 8°C colder than that over the adjacent snow‐free terrestrial surface and remained near 0°Cfor the full ablation period. The sensible heat flux was small and downward (negative), whereas the evaporative heat flux was small and positive. Thus, the energy used in melting the ice was approximately equal to that provided by the net radiation. Above‐freezing air temperatures decreased the albedo through surface melting thus increasing net radiation. This combination of higher temperature and large net radiation was associated with offshore winds and resulted in large ablation relative to periods with colder onshore winds. The ...