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，以改进和发展模型和方法，以准确和可靠地估计升华速率。本研究是一项为期五年的野外活动，利用涡旋相关塔测量海帽、水汽和动量的地表通量。涡旋相关观测将提供来自雪表面的总水汽通量，这可以归因于寒冷条件下的升华。测量将沿着从北部森林中的费尔班克斯延伸到北极阿拉斯加苔原和普拉德霍湾的海冰上的一条横断面进行。实地测量计划旨在覆盖整个北极的关键环境，并将在广泛的温度、湿度和冬季条件下进行，以及被连续和不连续的雪盖覆盖的景观，其中包括森林、冻土带、灌木、湖泊和冰。这一采样过程将确定适用于整个北极的升华过程。这将进一步指导新的升华物理模型的形成。在北极，冬季地表水分收支是降水和升华的函数。改进对实地升华和模拟组件的了解，并结合积雪深度信息，将能够确定未报告或不准确的地区的降水量。利用过去的数据记录，将生成一个关于地面降水、升华和雪水当量的长期泛北极再分析数据集。这些数据将允许进行趋势分析，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.