Abstract

The relationship between intraannual and interannual variations in the snow cover extent in the Northern Hemisphere, including Eurasia and North America and changes in surface air temperature was quantitatively estimated using satellite and reanalysis data for the period of 1979–2020. The estimates of the parameters of the snow cover extent sensitivity to temperature changes for the last four decades were compared with the estimates for the recent years (since 2005). The results of the correlation and cross-wavelet analysis indicate a general significant coherence and negative correlation between surface air temperature and the snow cover extent both for the entire Northern Hemisphere and separately for Eurasia and North America not only in the annual cycle but also in interannual variability for most months. Also, there is a positive correlation between the snow cover extent and surface air temperature in interannual variability, in particular, during the snow cover formation in the autumn months. It was found that the negative correlation between the snow cover extent and surface air temperature in Eurasia and North America for the recent years is higher than for the last four decades for most months except for the summer ones. The results indicate a weak coherence of interannual variations in the snow cover extent in Eurasia and North America, which is associated with the corresponding low coherence of interannual variations in surface air temperature for Eurasia and North America as a whole.

中文翻译：

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北半球卫星测得的积雪范围与地表气温的关系

摘要

使用 1979-2020 年期间的卫星和再分析数据定量估计了北半球（包括欧亚大陆和北美）积雪范围的年内和年际变化与地表气温变化之间的关系。将过去 40 年积雪范围对温度变化的敏感性参数的估计值与最近几年（自 2005 年以来）的估计值进行了比较。相关性和交叉小波分析的结果表明，无论是在整个北半球，还是在欧亚大陆和北美，地表气温与积雪范围之间普遍存在显着的相关性和负相关性，不仅在年周期中，而且在年际中大多数月份的变化。还，积雪范围与地表气温的年际变化呈正相关，尤其是在秋季积雪形成期间。研究发现，近年来欧亚大陆和北美地区的积雪范围与地表气温之间的负相关关系在除夏季以外的大部分月份都高于过去40年。结果表明，欧亚大陆和北美地区积雪范围的年际变化相关性较弱，这与欧亚大陆和北美整体地表气温年际变化的相关性较低有关。研究发现，近年来欧亚大陆和北美地区的积雪范围与地表气温之间的负相关关系在除夏季以外的大部分月份都高于过去40年。结果表明，欧亚大陆和北美地区积雪范围的年际变化相关性较弱，这与欧亚大陆和北美整体地表气温年际变化的相关性较低有关。研究发现，近年来欧亚大陆和北美地区的积雪范围与地表气温之间的负相关关系在除夏季以外的大部分月份都高于过去40年。结果表明，欧亚大陆和北美地区积雪范围的年际变化相关性较弱，这与欧亚大陆和北美整体地表气温年际变化的相关性较低有关。