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，以改进和开发模型和方法，从而准确可靠地估计升华率。本研究是一项为期五年的野外观测活动，利用涡动相关塔测量了海帽、水汽和动量的地面通量。涡动相关观测将提供来自雪表面的总水分通量，这可以归因于在寒冷条件下的升华。 测量将沿着一条从北方森林的费尔班克斯延伸的横断面进行，穿过阿拉斯加北极的苔原，然后是普鲁德霍湾的海冰。 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，湿度和冬季条件以及连续和不连续积雪覆盖的景观中进行，包括森林，苔原，灌木湖和冰。这一取样过程将确定适用于整个北极的升华过程。这将进一步指导升华的新物理模型的制定。在北极，冬季地表水分收支是降水和升华的函数。一个改进的知识升华从外地和建模组件加上雪深信息将允许确定降水的地区，降水要么没有报告或不准确。利用过去的数据记录，将生成一套关于地面降水、升华和雪水当量的长期泛北极再分析数据。这些数据将有助于进行趋势分析，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.