Changes in the Proportion of Precipitation Occurring as Rain in Northern Canada during Spring-Summer from 1979-2015

摘要

Changes in the form of precipitation have a considerable impact on the Arctic cryosphere and ecological system by influencing the energy balance and surface runoff.In this study,station observations and ERA-Interim data were used to analyze changes in the rainfall to precipitation ratio (RPR) in northern Canada during the spring-summer season (March-July) from 1979-2015.Our results indicate that ERA-Interim describes the spring-summer variations and trends in temperature and the RPR well.Both the spring-summer mean temperature [0.4℃-1℃ (10 yr)-1] and the RPR [2％-6％ (10 yr)-1] increased significantly in the Canadian Arctic Archipelago from 1979-2015.Moreover,we suggest that,aside from the contribution of climate warming,the North Atlantic Oscillation is probably another key factor influencing temporal and spatial differences in the RPR over northern Canada.