Future Changes of Snow in Alaska and the Arctic under Stabilized Global Warming Scenarios

Manifestations of global warming in the Arctic include amplifications of temperature increases and a general increase in precipitation. Although topography complicates the pattern of these changes in regions such as Alaska, the amplified warming and general increase in precipitation are already apparent in observational data. Changes in snow cover are complicated by the opposing effects of warming and increased precipitation. In this study, high-resolution (0.25 degrees) outputs from simulations by the Community Atmosphere Model, version 5, were analyzed for changes in snow under stabilized global warming scenarios of 1.5 degrees C, 2.0 degrees C and 3.0 degrees C. Future changes in snowfall are characterized by a north-south gradient over Alaska and an east-west gradient over Eurasia. Increased snowfall is projected for northern Alaska, northern Canada and Siberia, while milder regions such as southern Alaska and Europe receive less snow in a warmer climate. Overall, the results indicate that the majority of the land area poleward of 55 degrees N will experience a reduction in snow. The approximate threshold of global warming for a statistically significant increase in temperature over 50% of the pan-Arctic land area is 1.5 degrees C. The corresponding threshold for precipitation is approximately 2.0 degrees C. The global warming threshold for the loss of high-elevation snow in Alaska is approximately 2.0 degrees C. The results imply that limiting global warming to the Paris Agreement target is necessary to prevent significant changes in winter climates in Alaska and the Arctic.

Automated summary

Manifestations of global warming in the Arctic include temperature increases and increased precipitation. Changes in snowfall are complex due to the opposing effects of warming and increased precipitation. This study analyzed high-resolution simulation outputs to assess future changes in snow under different warming scenarios. The results indicate that regions like northern Alaska, northern Canada, and Siberia will experience increased snowfall, while milder regions like southern Alaska and Europe will receive less snow in a warmer climate. The study also highlights the importance of limiting global warming to prevent significant changes in winter climates in Alaska and the Arctic.