Winter Precipitation, Sublimation, and Snow-Depth in the Pan-Arctic: Critical Processes and a Half Century of Change

该项目将研究冬季升华过程，以改进和开发准确可靠地估计升华率的模型和方法。本研究是一个为期5年的野外研究项目，利用涡动相关塔测量地表热通量、湿度和动量。涡旋相关观测将提供来自雪表面的总水汽通量，这可归因于寒冷条件下的升华。测量将沿着从北方森林的费尔班克斯延伸到阿拉斯加北极苔原和普拉德霍湾海底海冰的横断面进行。实地测量计划旨在覆盖整个北极地区的关键环境，并将在广泛的温度、湿度和湿度条件下进行，以及被连续和不连续的积雪覆盖的景观，包括森林、苔原、灌木、湖泊和冰。这个取样过程将决定整个北极地区适用的升华过程。这将进一步指导新的升华物理模式的制定。在北极，冬季地表水分收支是降水和升华的函数。对来自野外的升华和模拟成分的改进知识，加上雪深信息，将允许在没有报告降水或降水不准确的地区确定降水。利用过去的数据记录，将生成一个长期的泛北极降水、升华和地面雪水当量的再分析数据集。这些数据将有助于趋势分析，并将变化与气候条件联系起来。

This project will investigate winter sublimation processes in order to improve and develop models and methods, which will accurately and reliably estimate sublimation rates. This study is as a five-year field campaign using eddy correlation tower to measure surface fluxes of hat, moisture and momentum. Eddy correlation observations will provide the total moisture flux from the snow surface, which can be attributed to sublimation in cold conditions. The measurements will be made along a transect extending from Fairbanks in the boreal forest, across the tundra of the Arctic Alaska and on tom the sea-ice in Prudhoe Bay. The field measurement program is designed to cover the key environments found throughout the Arctic and will be conducted during a wide range of temperature, humidity and win conditions as well as landscapes covered by continuous and discontinuous snow covers containing forests, tundra, shrubs lakes and ice. This sampling process will determine sublimation processes applicable throughout the Arctic. This will further guide formulation of new physical models of sublimation. In the Arctic, the winter surface moisture budget is a function of precipitation and sublimation. An improved knowledge of sublimation from the field and modeling components coupled with snow-depth information will allow for the determination of precipitation in areas where precipitation is either not reported or inaccurate. Using past data records, a long-term pan-Arctic reanalysis data set of precipitation, sublimation and snow-water equivalent on the ground will be generated. These data will allow trend analysis and relate changes to climatic conditions.