AN INVESTIGATION OF THE HYPOTHESES FOR FORMATION OF THE PLATY-RIDGED-POLYGONIZED TERRAIN IN ELYSIUM PLANITIA, MARS

The heavy snow years in China include 1955, 1957, 1964, and 2010, and light snow years include 1953, 1965, 1999, 2002, and 2009. The reduction in number of days with temperature below 0 °C and increase in mean air temperature are the main reasons for the delay of snow cover onset date and advance of snow cover end date. This explains why only 15 % of the stations show significant shortening of snow cover days and differ with the overall shortening of the snow period in the Northern Hemisphere.