Objectives The Greenland ice sheet is one of the main contributors to the global sea level rise, and the mass loss caused by its surface melting and meltwater runoff accounts for about 60% of the total mass loss of the ice sheet, so it is of great significance to study the surface melting of the Greenland ice sheet.
Methods Based on the 37 GHz vertical polarization passive microwave data of special sensor microwave imager sounder, the advanced diurnal amplitude variations (ADAV) method is proposed to detect the surface melting of the Greenland ice sheet.
Results Compared with the air temperature data of automatic weather stations, the average accuracy of the detection results of the ADAV method using dynamic threshold is better than that of the traditional diurnal amplitude variations method using a fixed threshold, and the passive microwave data time has no obvious influence on the detection accuracy.
Conclusions The freeze-thaw analysis of the Greenland ice sheet based on this method found that in 2019, the area with the most melting days on the ice sheet melted up to 165 d. The melting area reached the maximum on July 31st, accounting for 67% of the total ice sheet area. Three melting peaks arose in summer, and there were several winter melting events on the south coast. The ADAV method and its application to high spatial resolution passive microwave data have promoted the development of refining ice sheet freezing and thawing observations.
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