RAPID: Impacts of Deposition from Smoke-derived Black Carbon on the Greenland Ice Sheet and the Greater Arctic Cryosphere due to Transport from Record Setting Canadian Wildfires

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High latitude wildfires are increasing in frequency and intensity. Smoke and black carbon from Canadian wildfires is often transported to and deposited on the Greenland Ice Sheet, which then forces these ice-covered areas to absorb more solar energy, making them melt faster. Historically, wildfire intensity peaks later in summer, however 2023 has been marked by unprecedented early-season fires across Canada, although these events are projected to become more likely in future climate warming scenarios. Capturing data on black carbon deposition, as well as quantifying the impacts of this deposition on snow reflectance and melt, will lead to a better understanding of localized impacts of the early season smoke deposition on seasonal snowmelt. These valuable data will also help reduce uncertainty in future climate model projections of the effects a warming climate has on the Greenland Ice Sheet. This research will explore the impacts of the early onset, record-setting wildfires across Canada and quantify the wildfire-derived black carbon deposition on the Greenland Ice Sheet and the greater Arctic cryosphere. The radiative forcing attributable to the presence of black carbon on the cryosphere is one of the least constrained variables of global climate models, so a high level of uncertainty exists among modelled smoke deposition, concentrations of black carbon in snow, and the weathering crust on the surface of the ice sheet. This unique wildfire season provides an opportunity for model verification. The study will provide the first verification of the 1/3rd degree smoke deposition output from the Navy Aerosol Analysis Prediction System (NAAPS) global aerosol model, which provides high-resolution black carbon deposition as an output. The output has yet to be verified with ground observations of snow, so the project team will collect and analyze snow and water samples for refractory black carbon. The modelled black carbon deposition on the Greenland Ice Sheet from this year will also be compared to the previous 23-years of the model record. Darkening of snow and ice surfaces will also be explored with satellite remote sensing, as well as the role of the increased deposition of black carbon on snow albedo reduction, radiative forcing, the timing of seasonal snowmelt, as well as overall seasonal meltwater yield.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.