Abstract: The paper extracted the snow cover days (SCD),snow cover area (SCA),snow cover onset dates (SCOD) and snow cover melting dates (SCMD) in the Mongolian Plateau using the daily snow cover products MOD10C1 and MYD10C1 derived from the Terra and Aqua satellite from September 1,2002 to May 31,2017.At the same time,the temperature from the 108 weather stations across the plateau was used to analyze the relationship between snow cover characteristics and temperature.The paper used the pixel discrimination method to identify snowcovered pixels,and used the method of pixel accumulation to obtain the annual snow cover days of the plateau.The results show as follows: (1) The average SCD in the Mongolian Plateau ranged between 60 and 90 days,and it was correlated well with latitude.The SCD in the eastern region showed a slight upward trend and the southwestern region showed a significant downward trend.The SCOD in the plateau was mainly distributed between 315 and 335 days,and SCMD was mostly concentrated between 31 and 61 days.The SCOD in the east of the plateau showed a clear trend of moving early.(2) SCA presented “singlepeak” during the snow season.The SCA reached its maximum value in January,and the average SCA was 101.6×104 km2.The average annual SCA fluctuated greatly and there was a weak downward trend overall.(3) The maximum coverage area of snow has a significant correlation with temperature.From September to December,the average temperature was dropped by around 10 ℃ per month,and the temperature was relatively stable from December to February.From February to May,the average temperature was risen by around 10 ℃ per month.(4) There is a significant negative correlation between SCD,SCMD and temperature.SCOD has a significant positive correlation with temperature.A higher correlation can indicate that temperature is a key factor affecting snow cover.The paper used MODIS data to analyze the spatial and temporal distribution and changes of snow cover in the Mongolian Plateau,and could provide reference for the subsequent changes in water resources and vegetation growth in the Mongolian Plateau.At the same time,this paper also shows the dynamic changes of snow in the Mongolian Plateau during the years and the relationship with temperature,which provides a basis for disaster prevention and animal husbandry in the Mongolian Plateau.

Key words: Mongolian Plateau, snow cover, MODIS, climate change, temperature