Biological and Environmental Research - Earth and Environmental System Sciences
Earth and Environmental System Modeling

Unraveling Driving Forces Explaining Significant Reduction in Satellite-Inferred Arctic Surface Albedo Since the 1980s

TitleUnraveling Driving Forces Explaining Significant Reduction in Satellite-Inferred Arctic Surface Albedo Since the 1980s
Publication TypeJournal Article
Year of Publication2019
JournalProceedings of the National Academy of Sciences
Volume116
Number48
Pages23947-23953
Abstract / Summary

The Arctic has warmed significantly since the early 1980s and much of this warming can be attributed to the surface albedo feedback. In this study, satellite observations reveal a 1.25 to 1.51% per decade absolute reduction in the Arctic mean surface albedo in spring and summer during 1982 to 2014. Results from a global model and reanalysis data are used to unravel the causes of this albedo reduction. We find that reductions of terrestrial snow cover, snow cover fraction over sea ice, and sea ice extent appear to contribute equally to the Arctic albedo decline. We show that the decrease in snow cover fraction is primarily driven by the increase in surface air temperature, followed by declining snowfall. Although the total precipitation has increased as the Arctic warms, Arctic snowfall is reduced substantially in all analyzed data sets. Light-absorbing soot in snow has been decreasing in past decades over the Arctic, indicating that soot heating has not been the driver of changes in the Arctic snow cover, ice cover, and surface albedo since the 1980s.

URLhttp://dx.doi.org/10.1073/pnas.1915258116
DOI10.1073/pnas.1915258116
Journal: Proceedings of the National Academy of Sciences
Year of Publication: 2019
Volume: 116
Number: 48
Pages: 23947-23953
Publication Date: 11/2019

The Arctic has warmed significantly since the early 1980s and much of this warming can be attributed to the surface albedo feedback. In this study, satellite observations reveal a 1.25 to 1.51% per decade absolute reduction in the Arctic mean surface albedo in spring and summer during 1982 to 2014. Results from a global model and reanalysis data are used to unravel the causes of this albedo reduction. We find that reductions of terrestrial snow cover, snow cover fraction over sea ice, and sea ice extent appear to contribute equally to the Arctic albedo decline. We show that the decrease in snow cover fraction is primarily driven by the increase in surface air temperature, followed by declining snowfall. Although the total precipitation has increased as the Arctic warms, Arctic snowfall is reduced substantially in all analyzed data sets. Light-absorbing soot in snow has been decreasing in past decades over the Arctic, indicating that soot heating has not been the driver of changes in the Arctic snow cover, ice cover, and surface albedo since the 1980s.

DOI: 10.1073/pnas.1915258116
Citation:
Zhang, R, H Wang, Q Fu, P Rasch, and H Wang.  2019.  "Unraveling Driving Forces Explaining Significant Reduction in Satellite-Inferred Arctic Surface Albedo Since the 1980s."  Proceedings of the National Academy of Sciences 116(48): 23947-23953.  https://doi.org/10.1073/pnas.1915258116.