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

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°C-1°C (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.