Causes of declining Arctic surface albedo

A study examines the link between Arctic surface albedo and snow cover. Much of the Arctic’s significant warming since the 1980s can be attributed to surface albedo feedback, which is also important for mid-latitude climate change. To better understand the main contributors of decreasing surface albedo in the Arctic, Hailong Wang and colleagues compared global aerosol-climate models to monthly satellite observations of the Arctic captured between 1982 and 2014. The authors found an approximately 1.25–1.51% per decade absolute reduction in mean surface albedo during spring and summer. The authors also determined that reductions of terrestrial snow cover, snow cover fraction over sea ice, and sea ice extent equally contributed to the decline of Arctic surface albedo. Warming surface air temperature followed by declining snowfall were the primary drivers of decreasing snow cover fraction. Decreased snow cover fraction accounted for approximately 70% of the reduction in surface albedo, and reduced sea-ice fraction accounted for the remaining amount. Declining trend of soot in snow over the past 3 decades suggests that soot deposit is not a primary driver of decreasing snow cover and surface albedo in the Arctic, according to the authors.

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Article #19-15258: “Unraveling driving forces explaining significant reduction in satellite-inferred Arctic surface albedo since the 1980s,” by Rudong Zhang, Hailong Wang, Qiang Fu, Philip J. Rascha, and Xuanji
Wang.

MEDIA CONTACT: Hailong Wang, Pacific Northwest National Laboratory, Richland, WA; tel: 509-372-6106; email:

[email protected]