The vertical influence of temperature and precipitation on snow cover variability in the Central Tianshan Mountains, Northwest China

Seasonal snow cover in mountainous regions will affect local climate and hydrology. In this study, we assessed the role of altitude in determining the relative importance of temperature and precipitation in snow cover variability in the Central Tianshan Mountains. The results show that: (a) in the study area, temperature has a greater influence on snow cover than precipitation during most of the time period studied and in most altitudes. (b) In the high elevation area, there is a threshold altitude of 3,900 +/- 400 m, below which temperature is negatively correlated whereas precipitation is positively correlated to snow cover, and above which the situation is the opposite. Besides, this threshold altitude decreases from snow accumulated period to snow stable period and then increases from snowmelt period to snow-free period. (c) Below 2,000 m, there is another threshold altitude of 1,400 +/- 100 m during the snow stable period, below (above) which precipitation (temperature) is the main driver of snow cover.