Biomass Burning Emissions and Transport of Black Carbon (BC) to the Greenland Ice Sheet (GrIS) in 2013

International audienceThis study is the part of the SAGE project investigating the impact of light absorbing impurities (e.g., aerosols) on the Greenland Ice Sheet (GrIS). Previously ice-core snow samples collected on the GrIS indicated that black carbon (BC) concentrations were significantly enhanced, which could contribute to a decrease in albedo. Along with high levels of BC, the samples also showed significant amounts of ammonia, indicating the BC was sourced from biomass burning – likely from active forest fires in Eurasia and North America in July and August of 2013.In this study, we simulate the transport of potential smoke-filled air parcels using the NASA Langley Trajectory Model (LaTM), running in a backwards mode from selected ice-core sample sites on the GrIS from June 1st to August 31st 2013. 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. As a case study, we focus on an event in early August 2013 when episodic enhancements in black carbon deposition are found in snow pit observations. 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 from late July to early August. We ran backward and forward trajectories from the CALIOP aerosol signatures to verify coincidence with fire events and transport to the GrIS. We found large fires burning west side of the Hudson Bay in late July. CALIOP data captured thick smoke plumes on July 28th over that region and backward/forward trajectories and MODIS Terra/Aqua images support the transport of smoke from these fires to the GrIS