Spatial-temporal variability of snow cover and depth in Qinghai-Tibetan Plateau

Abstract:

Models predict that global warming may decrease snow cover in Northern Hemisphere, particular over the high latitude regions like the Qinghai-Tibetan Plateau. Due to the data limitations, there are only few studies to analyze the dynamics of snow cover over the Qinghai-Tibetan Plateau. In this study, we report on the spatial and temporal variabilities and trends in snow depth and cover days by ground observation data from 103 meteorological stations across the Qinghai-Tibetan Plateau. Our results show a very weak negative trend in snow depth and cover days over the period 1961-2010, but two different trends also can be detected by a piecewise regression analysis approach. A significantly negative correlation between snow depth and air temperature on various season is observed. The interannual variability of snow depth may result from the combined effects of temperature and precipitation. The long-term variation of snow cover days are agreement with the snowfall, but in contradiction to the warming trends. Over the Tibetan plateau, our results also show a later snow starting time (1.9±0.6 d decade^-1), an earlier snow ending time (-1.6±0.5 d decade^-1) and shorter snow cover duration (-3.5±0.9 d decade^-1) response to global warming.Models predict that global warming may decrease snow cover in Northern Hemisphere, particular over the high latitude regions like the Qinghai-Tibetan Plateau. Due to the data limitations, there are only few studies to analyze the dynamics of snow cover over the Qinghai-Tibetan Plateau. In this study, we report on the spatial and temporal variabilities and trends in snow depth and cover days by ground observation data from 103 meteorological stations across the Qinghai-Tibetan Plateau. Our results show a very weak negative trend in snow depth and cover days over the period 1961-2010, but two different trends also can be detected by a piecewise regression analysis approach. A significantly negative correlation between snow depth and air temperature on various season is observed. The interannual variability of snow depth may result from the combined effects of temperature and precipitation. The long-term variation of snow cover days are agreement with the snowfall, but in contradiction to the warming trends. Over the Tibetan plateau, our results also show a later snow starting time (1.9±0.6 d decade^-1), an earlier snow ending time (-1.6±0.5 d decade^-1) and shorter snow cover duration (-3.5±0.9 d decade^-1) response to global warming.