青藏高原不同下垫面地气交换参数的观测研究.doc

青藏高原不同下垫面地气交换参数的观测研究 摘要：青藏高原对大气的各种热力和动力效应是通过高原近地层和边界层逐渐影响到自由大气的，对青藏高原不同下垫面地气交换参数作观测分析意义十分重大。本文利用中国科学院青藏高原研究所在高原上建立的三个观测研究站（珠穆朗玛大气与环境综合观测研究站、纳木错多圈层综合观测研究站和藏东南高山环境综合观测研究站）2007年的气象观测资料分析了这些地区的气象要素特征和地气交换参数：动量总体输送系数CD、热量总体输送系数CH、动力学粗糙度z0m、热力学粗糙度z0h和热输送附加阻尼kB-1。得到了一些关于青藏高原大气边界层能量输送及微气象特征的新认识。 本论文得到的一些主要成果如下： 1. 得到了青藏高原上三个观测站一年的动量总体输送系数CD、热量总体输送系数CH、动力学粗糙度z0m、热输送附加阻尼kB-1以及地表发射率的值。 2．珠峰站的动力学粗糙度随季节变化不大；纳木错站和藏东南站的动力学粗糙度随季节变化比较明显。不同的计算方法可能会得到差异较大的动力学粗糙度的值。 3.热量总体输送系数总的看来要大于动量总体输送系数。动量总体输送系数在白天比较活跃，夜间值比较小；而热量总体输送系数在白天趋于稳定，夜间变化较大。动量总体输送系数与动力学粗糙度有着较好对应关系，较大的地表粗糙度很可能会导致较大的动量总体输送系数。 4. 热输送附加阻尼存在明显日变化，在白天，特别是下午较大，夜间比较平稳，相对为小值。热力学粗糙度日变化明显，很不稳定，热输送附加阻尼是表示热力学粗糙度一种较好的方法。 Abstract：An observational analysis of land- atmosphere interaction parameters in different landscapes of the Tibetan Plateau is of great significance. In this thesis, the meteorological exploration data collected from three research stations Qomolangma station, Namco station and Southeast Tibet station on the Tibetan Plateau are used to analyze the variation of momentum transfer coefficient CD , heat transfer coefficient CH , aerodynamic roughness length z0m , thermal roughness length z0h and excess resistance to heat transfer kB-1 . Some new concepts about the characteristics of the flux densities and micrometeorology in the atmospheric boundary layer on the Tibetan Plateau are obtained. The main results of this study are as follows: 1. The monthly surface roughness, bulk transfer coefficient, excess resistance to heat transfer and emissivity in all the three stations are obtained. 2. The inter-monthly variations of aerodynamic roughness length at Namco station and Southeast Tibet station are more evident than the Qomolangma station’s. Different methods to calculate roughness may lead to divergent results. 3. In general, heat transfer coefficient is larger than momentum transfer coefficient. Momentum transfer coefficient CD is quite changeable during the day but relatively stable and lower in the night. Heat