1961-2014年青藏高原积雪时空特征及其影响因子

利用青藏高原(下称高原)1961-2014年地面110个气象站积雪深度、积雪日数、气温和降水逐日资料,系统地分析了高原积雪深度和积雪日数时空特征,并进一步探究了高原积雪深度和积雪日数与气候因子和地理因子之间的关系。研究发现:1961-2014年高原年平均积雪深度和积雪日数分别为0.26 cm和23.78 d,空间和季节尺度上分布不均匀,且积雪深度和积雪日数大值并不完全重合;在整体变化趋势上,积雪深度和积雪日数均呈缓慢下降趋势,分别为-0.0080±0.0086 cm·(10a)^-1(p=0.36)和-0.64±0.47 d·(10a)^-1(p=0.17),但在数理统计上不显著,且各站点差异性大;积雪深度和积雪日数在春季、冬季和年表现为“减-增-减”的年代际变化特征,而在秋季为“增-减”的变化特征;气温与积雪深度和积雪日数均有较好的相关性,冬季的降水与积雪深度和积雪日数高度相关;积雪深度和积雪日数随海拔呈增加趋势,积雪日数与纬度也高度相关,但积雪深度与纬度的相关性不明显。

Spatial-temporal Characteristics of Snow and Influence Factors in the Qinghai-Tibetan Plateau from 1961 to 2014

Using observed daily data,which include the snow depth,the number of snow-cover days,temperature and precipitation data,from 110 meteorological stations over the Qinghai-Tibetan Plateau from 1961 to 2014,the spatial-temporal characteristics of the snow depth and the number of snow-cover days in Qinghai-Tibetan Plateau were analyzed and the relationship between them and climatic and geographical factors were explored.The results showed the annual average of the snow depth and the number of snow-cover days were 0.26 cm and 23.78 d,respectively.And the distribution was uneven on the spatial and seasonal scales.The great value of the snow depth and the number of snow-cover days did not completely coincide.As for trend analysis,both the depth and the number of days with snow cover showed a slow decline trend,which was-0.0080±0.0086 cm·(10 a)^-1(p=0.36) and-0.64±0.47 d·(10 a)^-1(p=0.17),respectively.But the trend was not significant in mathematical statistics.The trend varied significantly from stations to stations.The snow depth and the number of snow-cover days in spring,winter and annual were characterized by the interdecadal variation of "decrease-increase-decrease",while it showed "increasing-decreasing" in autumn.Temperature highly corresponded to the snow depth and the number of snow-cover days while precipitation was highly correlated with the snow depth and the number of snow-cover days in winter.The depth and days of snow cover decreased with the increase of sea level altitude.Latitude showed a high correlation with the number of snow-cover days while the correlation with the snow depth was not obvious.