冰云由于其自身独特的物理辐射性质，会对地-气辐射能量收支起到特殊而重要的作用，从而对气候变化产生显著影响。然而到目前为止，冰云在气候模式中的正确表征还存在很多问题，给气候预测造成了很大的不确定性。半干旱区是冰云广泛存在的区域，在这一地区开展冰云及其特性的研究，对于认清中纬度冰云的形成原因、特性分布及其对区域气候变化的影响和反馈作用有重要意义。本项目将利用高精度的毫米波雷达与激光雷达，对半干旱区冰云进行观测研究，反演冰云的宏微观物理特性，分析不同物理特性冰云与其小尺度动力特征以及大尺度气象场的关系，计算冰云的大气加热率和辐射强迫值，评估冰云对区域辐射能量收支的贡献。本项目的实施将在我国中纬度半干旱地区获取一批有价值的冰云物理与辐射特性数据，为验证模式模拟冰云特性的准确性，约束和改进模式对冰云的合理表征提供重要依据。

Ice clouds have a strong impact on the Earth’s radiative energy budget through their unique macro- and microphysical properties, and thus play an important role in the climate system. However, the representation of ice clouds in climate models continues to be a great challenge, which leads to a large uncertainty in the simulation of current and future climate. Since ice clouds are widely distributed over the semi-arid regions, a study of these clouds and their properties is critically important to understand mid-latitude ice clouds formation, and effects on climate and climate feedbacks. In this project, we propose to carry out a longterm ice cloud observation at the semi-arid region by using highly accurate microwave radar and lidar, retrieve ice cloud macro- and microphysical properties, examine the relationships between ice cloud and large-scale fields, calculate ice cloud radiative forcing, and quantify the effects of ice cloud on the radiative energy budget. Through this project, we will obtain a valuable dataset of ice cloud macro- and microphysical and their impacts on radiative energy budget to constrain climate models and improve the model representation of ice clouds.