Spatio-temporal changes of snowmelt in Greenland ice sheet based on SSM/I (SSMIS) data (1988-2016)

Abstract

The snowmelt of the Greenland ice sheets is of great significance to the study of global climate change. This paper is based on the 19.35 GHz horizontal polarization data and 37.00 GHz vertical polarization data of the Special Sensor Microwave/ Imager Sounder (SSMIS) and Special Sensor Microwave/ Image (SSM/I) carried by National Defense Meteorological Satellite Program (DMSP) from 1988 to 2016, by cross-polarization ratio (XPGR) algorithm (threshold value is -0.0158). The inter-annual trends of snowmelt area, annual average snowmelt onset, end date and duration in Greenland were studied. The results showed that the maximum snowmelt area was 2,080,000 km² in 2012, and the minimum was 1,115,000 km² in 1992. From 1988 to 2016, the snowmelt area of the Greenland ice sheets was increased by 2.8×10⁵ km², with a growth rate of 9.66×10³ km²/year. In the annual average change rate, there were earlier snowmelt onset date (0.16 days earlier each year), longer snowmelt duration (0.36 days longer each year) and later snowmelt end date (0.06 days later each year), and the snowmelt area was in the marginal region. The snowmelt area of the southern margin is the largest, and there are obvious regional differences. The snowmelt of Greenland ice sheets changes greatly and shows a periodic change rule in the annual mean snowmelt variation.