Estimates of the dependence of snow cover extent on surface air temperature variations of the Northern Hemisphere for the last several decades

Understanding the ongoing climate change is impossible without evaluating the contributions of both anthropogenic and natural variabilities. In present paper, natural variability is examined by estimating the dependence of snow cover extent on surface air temperature variations of the Northern Hemisphere for the last several decades. The relationship was evaluated with correlation analysis of the results of simulations with the ensemble of global climate models CMIP6 and the respected satellite and ERA5 reanalyzes data. The estimated snow cover extent sensitivity to the temperature changes for the last four decades (1979 2019) has been compared with that obtained for the last fifteen years (2005–2019). Seasonal features of the snow cover extent temperature relationship have been noted, particularly during the formation of snow cover in autumn. An increase in the absolute value of the sensitivity parameter of the snow cover extent to the surface air temperature changes is noted, with an overall statistically insignificant negative correlation for the last four decades.