地形云降水过程对大气水循环和能量平衡起着十分重要的作用，而风吹雪过程会影响地形降水，并导致积雪再分布，这对地面水资源有重要影响。目前关于风吹雪对地形降水的影响还不清楚，仅靠观测无法区分云内冰晶和风吹雪粒子，因此需要通过高精度模拟来进行研究，但是，目前还没有研究将风吹雪方案加入大气模式。. 本项目基于在中天山和中落基山的粒子谱观测资料，建立风吹雪粒子谱函数，将其代入风吹雪参数化方案中，并将该化方案加入WRF模式，对在中天山和怀俄明观测到的四次冬季地形云降水个例进行高精度模拟。针对每个个例分别进行两组模拟，一组包含风吹雪方案，另一组不包含。通过观测期间获取的飞机、雷达等观测资料对模拟结果进行验证，并结合模拟结果与观测资料来深入分析风吹雪对冬季地形云微物理及其降水结构的作用，揭示风吹雪对地形云降水的影响。研究成果有助于加强对地形云降水过程的认识，提高我国在高海拔和高纬度地区的天气预报能力。

Orographic clouds and precipitation play important roles in the water cycle and energy balance. Blowing snow, as a common land surface process over high mountains and at high latitudes, have strong impacts on the orographic precipitation, and can result in redistribution of snowpack, which is important to the surface water resources. However, the impacts of blowing snow on orographic precipitation are poorly understood. Since the ice initiated in clouds and blowing snow particles cannot be partitioned using observation only, it is necessary to use high-resolution simulations to improve our understanding on the impact of blowing snow on orographic clouds. However, few studies have implemented a blowing snow scheme in atmospheric models.. This proposal aims to develop the size spectrum of of blowing snow using the ground-based particle measurements over Central Tianshan Mountain and Central Rockies. The size spectrum will be used in a previously developed blowing snow parametrization, which will be implemented in the Weather Research and Forecast model. High-resolution simulations will be conducted for four wintertime orographic precipitation cases observed over Tianshan and in Wyoming. For each case, two simulations will be made, one includes the blowing snow scheme, and the other not. The modeled results will be evaluated using airborne measurements and ground-based radar measurements. Using high-resolution simulations and observations, the microphysics and precipitation properties of orographic clouds will be analyzed in detail. The results will be helpful to improve our understandings on orographic precipitation, and the capability of weather forecasting over high mountains and at high latitudes.