Contribution of Snow Cover Decline to Projected Warming Over North America.

Given the critical role that snow plays in modulating current climate, it is vital to examine the contribution of the projected snow decline to the future warming. This is investigated over North America using regional climate modeling experiments with prescribed current and future snow conditions. Results indicate that the decline in snow contributes to future warming by up to 2°C and 4°C, respectively, to annual and spring temperature increases. Results also show that decline in snow depth and cover lead to the attenuation (amplification) of cold (warm) extremes. The rate of intensification of warm extremes is higher over the snow‐abundant regions of northern Canada—where current snow cover fraction is close to one. The largest attenuation in cold extremes, on the other hand, is over snow marginal regions of the Great Plains and Prairies. These results demonstrate the spatiotemporal differences in projected changes exclusively associated with snow cover and depth decline. Plain Language Summary: Climate models suggest a decline in snow cover and snow depth in future warmer climate. This decline in snow cover in turn warms the climate further through the snow‐albedo feedback. However, the contribution of extra warming due to snow loss is highly uncertain and needs further investigation. The aim of this study is to quantify the role of projected snow cover decline on the overall future warming of North America using regional climate model simulations prescribed with current and future snow depth/cover conditions. Our results indicate that snow loss‐related share to future warming is maximum over the present‐day snow‐atmosphere coupling hot‐spot regions and contributes up to 3–4°C to the overall warming. Our results also highlight the sensitivity of temperature extremes and their spatial distribution to the decline in snow cover and depth. The rate of intensification of warm extremes is higher over snow abundant regions of northern Canada—where snow cover fraction is close to one. The largest attenuation in cold extremes, on the other hand, is over snow marginal regions of the Great Plains and Prairies. These results demonstrate the importance of snow‐atmosphere feedbacks on future regional extremes. Key Points: A detailed investigation of the contribution of projected snow decline to the overall future warming over North America is presentedSnow depth/cover decline‐related contribution to overall warming is assessed and it reaches up to 4°C in springFuture snow depth/cover changes contribute to intensifying (attenuating) warm (cold) extremes over snow abundant (marginal) regions [ABSTRACT FROM AUTHOR]