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

高纬度野火的频率和强度正在增加。加拿大野火产生的烟雾和黑碳经常被运送到格陵兰冰盖并沉积在上面，然后迫使这些冰盖区域吸收更多的太阳能，使它们融化得更快。从历史上看，野火强度在夏季晚些时候达到峰值，但2023年加拿大各地发生了前所未有的早期火灾，尽管预计这些事件在未来气候变暖的情况下更有可能发生。捕获黑碳沉积的数据，以及量化这种沉积对雪反射率和融化的影响，将导致更好地了解季节性融雪的早期烟雾沉积的局部影响。这些有价值的数据还将有助于减少未来气候模型预测气候变暖对格陵兰冰盖影响的不确定性。这项研究将探讨加拿大各地早期发生的创纪录野火的影响，并量化格陵兰冰盖和更大的北极冰冻圈上野火产生的黑碳沉积。由于黑碳在冰冻圈中的存在而产生的辐射强迫是全球气候模式中受约束最少的变量之一，因此在模拟的烟雾沉积、雪中黑碳的浓度和冰盖表面的风化壳之间存在很高的不确定性。这个独特的野火季节为模型验证提供了机会。该研究将首次验证海军气溶胶分析预测系统（NAAPS）全球气溶胶模型的1/3度烟雾沉积输出，该模型提供高分辨率的黑碳沉积作为输出。这一结果还有待于地面观测雪的验证，因此项目团队将收集和分析雪和水样本中的耐火黑碳。今年格陵兰冰盖上的模拟黑碳沉积也将与之前23年的模型记录进行比较。还将利用卫星遥感探索冰雪表面的变暗，以及黑碳沉积的增加对减少积雪的作用、辐射强迫、季节性融雪的时间以及整体季节性融水产量。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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.