Albedo Dynamics of High Northern Latitudes: Phenology and Fire Recovery from a Circumpolar Albedo Product
Crystal Schaaf, University of Massachusetts Boston, crystal.schaaf@umb.edu
Angela Erb, University of Massachusetts Boston, angela.erb@umb.edu
Arthur Elmes, University of Massachusetts Boston, arthur.elmes@gmail.com
Charlotte R Levy, UMass Boston, charlotte.levy@umb.edu (Presenter)
Zhuosen Wang, NASA GSFC/University of Maryland, zhuosen.wang@nasa.gov
Qingsong Sun, NASA GSFC, qingsong.sun@nasa.gov
Albedo is a measurement of the solar irradiance reflected by a surface, and is a key driver of the global energy budget and effective radiative forcing on the landscape scale. In northern regions, albedo may show changes in land cover, snow and ice extent, fire scar and recovery, and seasonal phenology. We generated circumpolar (> N 40?) albedo by combining Landsat-8 and Sentinel-2 30 m albedo products and Landsat near-nadir observations with appropriate surface anisotropy information from the MODIS or VIIRS BRDF products. We validated this albedo product against taiga and tundra ABOVE network sites with in-situ albedo measurements. Our results showed generally good agreement between satellite and ground albedo; poorer agreement at the Swiss Camp site were shown to result from detection of meltwater by the satellite that was not visible at the scale of the tower. Finally, we demonstrate how fine-scale albedo measurements over the Saskatchawan can be used to track albedo seasonality and phenology pre and post fire, and over long-term climatic change. The 2015 Rock Fire was shown to lower albedo in the spring and summer season and to shift spring melt and green-up to earlier in the season. Retrievals over the entire region show an overall, gradual decrease in albedo, and an earlier onset of albedo darkening during the spring and summer season. Our results demonstrate how fine-scale circumpolar albedo can track long-term changes in the phenology of snow melt and greening, demonstrate impacts of and recovery from wildfire, and open opportunities for high latitude researchers.
Presentation: iPoster
Associated Project(s):
Presentation Type: Poster
Science Theme: Crosscutting