black carbon
; fossil fuel
; snow
; Arctic
; article
; biomass
; climate change
; combustion
; fire
; forest fire
; Greenland
; high temperature
; ice sheet
; melting point
; Northern Hemisphere
; priority journal
; remote sensing
; sediment
; summer
; temperature
; warm temperature
; Arctic Regions
; Carbon
; Climate Change
; Fires
; Freezing
; Global Warming
; Greenland
; Ice Cover
; Snow
; Trees
英文摘要:
In July 2012, over 97% of the Greenland Ice Sheet experienced surface melt, the first widespread melt during the era of satellite remote sensing. Analysis of six Greenland shallow firn cores from the dry snow region confirms that the most recent prior widespread melt occurred in 1889. A firn core from the center of the ice sheet demonstrated that exceptionally warm temperatures combined with black carbon sediments from Northern Hemisphere forest fires reduced albedo below a critical threshold in the dry snow region, and caused the melting events in both 1889 and 2012. We use these data to project the frequency of widespread melt into the year 2100. Since Arctic temperatures and the frequency of forest fires are both expected to rise with climate change, our results suggest that widespread melt events on the Greenland Ice Sheet may begin to occur almost annually by the end of century. These events are likely to alter the surface mass balance of the ice sheet, leaving the surface susceptible to further melting.
Keegan, K.M., Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, United States; Albert, M.R., Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, United States; McConnell, J.R., Desert Research Institute, Nevada System of Higher Education, Reno, NV 89512, United States; Baker, I., Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, United States
Recommended Citation:
Keegan K.M.,Albert M.R.,McConnell J.R.,et al. Climate change and forest fires synergistically drive widespread melt events of the Greenland Ice Sheet[J]. Proceedings of the National Academy of Sciences of the United States of America,2014-01-01,111(22)