The Changing Face of Arctic Snow Cover: A Synthesis of Observed and Projected Changes

Abstract

Analysis of in situ and satellite data shows evidence of different regional snow cover responses to the widespread warming and increasing winter precipitation that has characterized the Arctic climate for the past 40-50 years. The largest and most rapid decreases in snow water equivalent (SWE) and snow cover duration (SCD) are observed over maritime regions of the Arctic with the highest precipitation amounts. There is also evidence of marked differences in the response of snow cover between the North American and Eurasian sectors of the Arctic, with the North American sector exhibiting decreases in snow cover and snow depth over the entire period of available in situ observations from around 1950, while widespread decreases in snow cover are not apparent over Eurasia until after around 1980. However, snow depths are increasing in many regions of Eurasia. Warming and more frequent winter thaws are contributing to changes in snow pack structure with important implications for land use and provision of ecosystem services. Projected changes in snow cover from Global Climate Models for the 2050 period indicate increases in maximum SWE of up to 15% over much of the Arctic, with the largest increases (15-30%) over the Siberian sector. In contrast, SCD is projected to decrease by about 10-20% over much of the Arctic, with the smallest decreases over Siberia (\10%) and the largest decreases over Alaska and northern Scandinavia (30-40%) by 2050. These projected changes will have far-reaching consequences for the climate system, human activities, hydrology, and ecology.

Temperature and Snow-Mediated Moisture Controls of Summer Photosynthetic Activity in Northern Terrestrial Ecosystems between 1982 and 2011

“…Recent studies based on satellite and in-situ observations have shown that rapid winter/spring warming and changes in interdecadal climate modes since around 1991 have led to a significant decline in snowpack accumulation and snow cover duration across most of Alaska and Canada despite increasing winter precipitation [36][37][38]94,95]. In some regions of the North American Cordillera, the recent loss of snowpack is unprecedented over the past millennium [96].…”

Spatiotemporal variability of snow depth across the Eurasian continent from 1966 to 2012

“…Many studies on snow depth have focused on local and regional scales over Russia (Ye et al, 1998;Kitaev et al, 2005;Bulygina et al, 2009Bulygina et al, , 2011Brasnett, 1999) and the Tibetan Plateau (TP) (Li and Mi, 1983;Ma and Qin, 2012) and have revealed significant regional changes. It has been reported that annual mean snow depth has increased in northern Eurasia and the Arctic during the last 70 years (Ye et al, 1998;Kitaev et al, 2005;Callaghan et al, 2011;Liston and Hiemstra, 2011) with large regional differences (Bulygina et al, 2009(Bulygina et al, , 2011Ma and Qin, 2012;Stuefer et al, 2013;Terzago et al, 2014). Changes in snow depth are primarily affected by air temperature and precipitation.…”

Exchange of CO<sub>2</sub> in Arctic tundra: impacts of meteorological variations and biological disturbance

“…Further, Arctic ecosystems have experienced an intensified warming tendency, reaching almost twice the global average (ACIA, 2005;AMAP, 2011;Callaghan et al, 2012c;Serreze and Barry, 2011). The projected Arctic warming is also expected to be more pronounced in coming years (AMAP, 2011;Callaghan et al, 2012a;Christensen et al,4468 E. López-Blanco et al: Exchange of CO 2 in Arctic tundra perature, precipitation and growing season length will likely increase in the Arctic (ACIA, 2005;Christensen et al, , 2004IPCC, 2007). Given this situation, an improvement in our process-based understanding of CO 2 exchanges in the Arctic and their climate sensitivity is critical (McGuire et al, 2009).…”