Location: Hydrology and Remote Sensing LaboratoryTitle: Greenland surface albedo changes 1981-2012 from satellite observations) Author
Submitted to: Geophysical Research Letters
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/7/2013
Publication Date: 8/14/2014
Publication URL: handle.nal.usda.gov/10113/59886
Citation: He, T., Liang, S., Yu, Y., Gao, F.N., Liu, Q. 2014. Greenland surface albedo changes 1981-2012 from satellite observations. Geophysical Research Letters. DOI:10.1088/1748-9326/8/4/044043. Interpretive Summary: The Greenland ice sheet contains a massive amount of fresh water, which if all were melted would cause a 6-7 m increase in mean sea level. A warming trend since the early 1980s in the Arctic, identified from satellite observations, has caused significant melt events in Greenland over the last three decades. The melt of snow and ice has caused a change in the surface albedo (the fraction of incoming solar radiation reflected back into the atmosphere) which plays a key role in determining the Earth’s radiation balance. Assessments of Greenland albedo variability have been conducted by using different datasets over different time periods. However, due to the limited data availability and data inconsistencies, there is a lack of a reliable assessment of satellite albedo products over the last three decades. This paper analyzes the change of surface albedo over Greenland using a 32-year consistent satellite albedo product from the Global Land Surface Satellite (GLASS) project together with ground-truth measurements. Results show the albedo changes before 2000 are not statistically significant. The most significant change (decrease) after 2000 occurred at elevations 1000-1500 m above mean sea level. Discrepancies were found between the satellite-based albedo products and the albedo values predicted from General Circulation Models (GCMs) documented in the Intergovernmental Panel on Climate Change 5th Assessment Report (IPCC AR5). Understanding the impacts of global climate change on water resources is critical for the USDA in order to develop mitigation strategies for sustainable agricultural production.
Technical Abstract: Significant melt over Greenland has been observed during the last several decades associated with extreme warming events over the northern Atlantic Ocean. An analysis of surface albedo change over Greenland is presented, using a 32-year consistent satellite albedo product from the Global Land Surface Satellite (GLASS) project and ground measurements. Results show a large decrease in surface albedo after 2000 (-0.0024 yr-1) while the albedo change before 2000 is not statistically significant. The most significant decrease after 2000 happened at the elevations 1000-1500 m above sea level (-0.0059 yr-1) associated with surface temperature increase. Change in surface albedo offsets the dimming over Greenland mostly caused by the increased cloudiness. Discrepancy was found between satellite albedo products and the Intergovernmental Panel on Climate Change 5th Assessment Report (IPCC AR5) General Circulation Models (GCMs) outputs on the changes not only in the magnitude but also in the trend.