中文摘要：

欧亚中高纬地区的积雪是影响气候的重要因子,但是观测台站稀疏且记录只到1996年,导致积雪观测资料严重缺乏。基于目前国际上应用较为广泛的3套再分析资料：美国国家大气海洋局（NOAA）的20世纪再分析资料（NCAR-20th century reanalysis）、欧洲中期天气预报中心（ECMWF）的再分析资料（ERA-Interim）及日本气象厅（JMA）的全球大气再分析资料（JRA-55）,利用前苏联站点观测的雪深资料评估雪深再分析资料在欧亚大陆区域的适用性。结果表明：3套再分析资料对积雪的时空变化均具有一定的描述能力;其中,尤以JRA-55再分析资料与观测事实最为接近,能较好揭示欧亚中高纬雪深变化的空间分布特征,反映雪深的长期变化趋势。JRA-55再分析资料揭示的欧亚雪深与169站观测有90%吻合,20世纪再分析资料有76%一致,而ERA-Interim再分析资料只有一半。区域尺度上,JRA-55再分析资料揭示的欧洲、西伯利亚南部雪深在1961～1990年的变化与观测是正相关,相关系数达到0.91、0.87,而20世纪再分析资料仅有0.77、0.32。长时间序列的雪深资料（JRA-55）表明欧亚大陆积雪存在年代际的变化特征：1960年代积雪偏少;1970年代偏多;从1980年代开始呈现减少趋势,持续至20世纪末,并且积雪的减少是高纬度积雪变化造成的。

英文摘要：

Snow over the middle–high latitudes of Eurasia has been shown as an important forcing mechanism of climate variability, but observation stations in this region are sparsely distributed and recorded only until 1996. Based on three current widely used reanalysis datasets—the twentieth century reanalysis of the National Center for Atmospheric Research（NCAR-20 th century reanalysis）, supplied by the U.S. National Oceanic and Atmospheric Administration, the interim reanalysis of the European Centre for Medium-Range Weather Forecasts（ERA-Interim）, and the Japanese 55-year reanalysis（JRA-55）, supplied by the Japan Meteorological Agency—we evaluate the applicability of these three reanalysis datasets using historical soviet daily snow depth. Results show that the three reanalysis datasets can describe the spatiotemporal features of winter snow depth in the middle–high latitudes of Eurasia, especially the JRA-55 dataset, which shows the best consistency with station observations. There is 90% consistency between JRA-55 and station observations（174 stations）, while the NCAR-20 th century reanalysis shows 76% and ERA-Interim only 50%. Even on regional scales JRA-55 exhibits good consistency with stations in Europe and southern Siberia during 1961–1990; their positive correlation coefficients are 0.91 and 0.87, while for the NCAR-20 th century reanalysis they are 0.77 and 0.32. JRA-55 exhibits interdecadal variation of snow depth over the middle–high latitudes of Eurasia： Snow depth is less in the 1960 s but more in the 1970s; from the 1980 s, it shows a decreasing trend that continues until the 20 th century, and this decrease in snow depth is caused by changes in the high latitudes.