古尔班通古特沙漠非均匀下垫面陆气相互作用观测与模拟研究

Gurbantünggüt Desert came as the only largest fixed and semi-fixed desert in China, has special underlying surface characteristics such as long snow cover in winter, exuberant growth of ephemeral plants in spring, stable growth of shrubs in summer and autumn, etc. It has special regularity in energy and water cycle, and has important influence on regional climate. There have been few systematic observations and simulations of Land atmosphere interaction on the Inhomogeneous underlying surface of the desert, and problems such as lack of understanding of Land atmosphere interaction under complicated conditions.Based on these points of view, In this project，We will carry out the experiments of intensive observation of land surface process and three-dimensional observation of atmospheric boundary layer based on GPS radiosonde, tethered balloons and wind profile radar In the hinterland of Gurbantünggüt Desert. This study will also investigate the structure of the atmospheric boundary layer and the evolution of the land surface process on the inhomogeneous underlying surface,as well as the influence mechanism of the inhomogeneous change of the underlying surface on the regional land-atmosphere exchange of the Gurbantünggüt Desert. This project will also give the parameters and schemes of land surface process suitable for complicated conditions in this region and improve the application and simulation ability of Noah land surface model in this area, which may provide a basis for improving the regional numerical model's ability to predict desert weather.

古尔班通古特沙漠是我国最大的固定、半固定沙漠，具有冬季积雪持续时间长、春季短命植物生长旺盛、夏秋季灌木生长稳定等独特的下垫面特征，在物质、能量以及水分循环方面有着特殊的规律，也对区域气候有着十分重要的影响。对该沙漠非均匀下垫面特性的陆气相互作用系统性观测和模拟研究一直较少，且存在着复杂条件下的边界层结构和陆—气相互作用认识不足。因此，本项目拟在古尔班通古特沙漠腹地开展陆面过程加密观测试验和基于GPS探空、系留气球和风廓线雷达的大气边界层立体观测试验，研究古尔班通古特沙漠非均匀下垫面大气边界层结构和陆面过程演变规律，揭示下垫面非均匀变化对该区域地气交换的影响机制，给出适合于该区域复杂条件的陆面过程参数及参数化方案，改进Noah陆面模式在该区域的应用模拟能力，从而为提高区域数值模式对沙漠天气预报能力提供基础支撑。

本项目在北疆古尔班通古特沙漠腹地陆气相互作用观测站持续进行陆面过程观测试验基础上，基于大孔径闪烁仪和涡动相关系统、地表辐射收支观测系统的矩阵试验，基于风廓线雷达、微波辐射计、GPS探空的立体观测试验，生成了中国最大固定/半固定沙漠的陆气相互作用观测数据集，系统分析了该沙漠区域的近地边界层、对流边界层演变规律，沙漠陆面过程演变特征和特征参数，探究了下垫面覆被变化对陆面过程和边界层的影响。具体为：①给出了古尔班通古特沙漠非均匀下垫面的边界层风速、温度、比湿、大气稳定度、湍流强度等大气边界层要素的演变规律，发现了该沙漠夜间湍流遵从曲棍球理论；探究了地表辐射收支、日照时数、紫外辐射、能量平衡、地表热源等陆面过程演变规律，发现该沙漠有效能量主要以感热通量的形式分配；②定量评估了下垫面覆被变化（冬季稳定积雪、春季短命植物生长旺盛、夏秋季灌木稳定生长）对边界层结构、陆面过程和陆面过程参数的影响；③给出古尔班通古特沙漠地表反照率、空气动力学粗糙度、地表热力学粗糙度、总体输送系数、土壤导热率等陆面过程特征参数；④给出了该区域复杂下垫面的陆面过程模式的各种参数化方案，开展了Noah陆面模式离线模拟工作和WRF模式在沙漠区的适用性评价研究。此外，对该区域的碳循环规律进行研究，解释了该沙漠在生长季属于碳汇的实事。.目前已发表标注本项目资助论文15篇，其中第一资助和第二资助文章12篇，其中SCI 9篇，授权实用新型专利1项，培养毕业研究生3人，团队7人职称晋升。项目完成任务书计划的任务。