Long-Term Observation of the Arctic Sea Ice Melt Onset from Microwave Radiometry

An exercise is carried out to analyse the variability in the Arctic snowmelt onset dates (SMOD) using 34 years of passive microwave radiometry data. For this study, the sea ice prevailing regions above 40° N have been clustered into thirteen sectors. Trend analysis of the SMOD shows that 10 sectors have negative trends meaning earlier melt onsets. Negative trends in the East Siberian Sea, Kara Sea, Laptev Sea, Chukchi Sea, Central Arctic Ocean, Canadian Archipelago, Beaufort Bay and Barents Sea are all statistically significant. Although the Greenland Sea shows a statistically significant positive trend is obtained. Inter-sectorial correlation shows strong positive correlations in many sectors such as between the Canadian Archipelago and the Central Arctic, Chukchi Sea—Central Arctic, East Siberian-Central Arctic. Moreover, correlation with the Arctic Oscillation (January to March average) shows negative correlations with the SMOD.