Biomass Burning and the 2012 Greenland Ice Sheet (GrIS) melt

This study is the part of the Sunlight Absorption on the Greenland ice sheet Experiment (SAGE) project investigating the impact of light absorbing impurities (e.g., aerosols) on the Greenland Ice Sheet (GrIS). Satellite observations, [e.g. Oceansat-2 (OS2) and the Moderate-resolution Imaging Spectroradionmeter (MODIS)] discovered an unusually large melt event in July 2012. NASA sensors showed that nearly 98.6% of the GrIS experienced melting at or near surface [Nghiem et al., 2012]. In this study, we question the extent to which biomass burning derived aerosols enhanced melting across the GrIS. Random points [59 total, 13 coincident with snow pit sites and 46 gridded] are selected across the entire extent of the GrIS from April 1st to August 31st 2012, and then the NASA Langley Trajectory Model (LaTM) is used to simulate the transport of potentially smoke-filled air parcels backwards for 5 days form these points, evaluation the back trajectory for coincidence with active fire detections. The trajectory model is initialized for 24-hour sustained injection from each site, and air parcels are released from the surface to 2 km at 200m intervals. With the trajectory model outputs, we are able to identify trajectories that have coincidences with fires. We focus on events in April through July when the GrIS albedo was dramatically decreased. We also utilize Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) data to verify smoke-aerosol signatures in boreal regions based on the NASA LaTM results. The results of this study will help us better understand the transport of biomass burning plumes and black carbon deposition that could lead to enhanced GrIS melting.