Daily Averages of Aerosol Properties in Summit, Greenland

The collaborative team will take advantage of the currently funded Greenland Inland Traverse (GrIT) traveling between Thule and Summit Greenland to access a spatially diverse area of the GIS in order to better understand albedo variability and the snow properties that influence albedo. The GrIT route offers a unique opportunity to study a wide range of snow accumulation zones (i.e. the ablation zone, soaked snow zone, the percolation zone and the dry snow zone) across Greenland, which are expected to have a broad range of albedo values as well as significant variability in snow physical properties and concentrations of light absorbing compounds (i.e. dust, elemental carbon, and brown carbon). The project's field component will take place over two seasons during the spring of 2013 and 2014. The approach will include stopping along the traverse to collect coincident daily measurements of snow spectral albedo, snow physical properties (i.e. specific surface area, density), surface snow light absorption properties (i.e. wavelength dependent absorption of water soluble compounds and particulates), and the concentrations of trace elements, organic, and elemental carbon. Additionally, the temporal evolution of spectral albedo will be monitored continuously during the sunlit months using autonomous stations deployed along the traverse route to track seasonal variations of snow albedo and to help attribute these variations to the physical and chemical composition of the snow. The results of this project will yield a unique data set characterizing the temporal and spatial variability of surface albedo as well as the physical and chemical properties of Greenland snow, which are broadly useful to both modeling, ice mass balance, and remote sensing communities. Conference presentations, rapid publication of results, and most importantly close collaboration with modelers, (i.e. through work with the CESM PCWG) will ensure that this knowledge is used to improve process parameterizations in predictive global climate models. The team will also build on international collaborations begun in the Dartmouth IGERT program, including a week-long ambassadorship to Nuuk by co-PI Polashenski including lectures at the college and Katuuaq cultural center. Graduate, undergraduate, and high school student training will also be included in the project.

合作团队将依托当前已获批资助的、往返于格陵兰图勒（Thule）与格陵兰冰盖之巅（Summit Greenland）的格陵兰内陆科考穿越队（Greenland Inland Traverse, GrIT），前往格陵兰冰盖（Greenland Ice Sheet, GIS）内空间分布多样的区域，以深入解析反照率变异性及其影响的积雪属性。格陵兰内陆科考穿越队的行进路线，为研究格陵兰全域广泛的积雪积累带（即消融带、湿雪带、渗滤带与干雪带）提供了独特契机；这些区域的反照率值跨度极大，同时积雪物理属性与吸光化合物（即尘埃、元素碳与棕碳）的浓度也存在显著差异。本项目的野外工作将在2013年与2014年春季的两个科考季开展。本次野外作业将沿穿越路线停靠，同步开展每日积雪光谱反照率、积雪物理属性（比表面积、密度）、表层积雪吸光特性（水溶性化合物与颗粒物的波长依赖性吸收），以及微量元素、有机碳与元素碳浓度的同步观测。此外，项目将沿穿越路线部署自动监测站，在极昼月份持续监测光谱反照率的时间演化过程，以追踪积雪反照率的季节变化，并将这些变化归因于积雪的物理与化学组成。本项目的研究成果将形成一套独特的数据集，刻画格陵兰表层反照率的时空变异性以及格陵兰积雪的物理与化学属性，该数据集对建模、冰量平衡与遥感领域均具有广泛应用价值。通过学术会议汇报、成果快速发表，以及最为关键的与模型研发者的深度合作（例如与社区地球系统模型参数化工作组（Community Earth System Model Parameterization Working Group, CESM PCWG）开展协作），本项目将确保相关研究成果用于改进全球气候预测模型中的过程参数化方案。团队还将延续达特茅斯学院IGERT项目（Dartmouth IGERT program）已启动的国际合作，包括共同首席研究员（Co-Principal Investigator, co-PI）波拉申斯基（Polashenski）赴努克（Nuuk）开展为期一周的学术交流，期间将在当地高校与卡图阿克文化中心（Katuuaq cultural center）进行讲座。本项目还将涵盖研究生、本科生与高中生的科研培训工作。