Abstract: An experiment on heterogeneous underlying surface was conducted by Peking University and the Institute of Atmospheric Physics, Chinese Academy of Science (CAS), in Baiyangdian in September of 2005. High-precision humidity and temperature measurements were made at two different sites with underlying surfaces of land and water, respectively. Profiles of temperature and humidity were also studied. The results indicate that the structures of the atmospheric boundary layer (ABL) over Baiyangdian Wetland are different from that in other places, such as humidity and temperature inversion appears frequent. It is found that the ABL over the land surface has a lower temperature, shallower ABL depth, but higher humidity, compared with that over the lake site. The possible factors are the prevailing winds, energy budget and land-air interaction. This experiment also provide an opportunity to test the quality of humidity sensor and temperature sensor designed by Peking University.

Key words: Baiyangdian wetland, high-precision profiles of humidity and temperature, atmospheric boundary-layer

摘要： 2005年9月北京大学与中国科学院大气物理研究所联合在白洋淀湿地地区开展非均匀下垫面的大气边界层综合野外观测实验，利用新型高精度温湿度探空系统分别在陆地和水面两种下垫面进行连续观测。实验结果显示水陆两种下垫面的大气边界层结构具有明显特征：不同时刻、不同高度出现多层逆湿、逆温现象及清晰的边界层顶位置。同时发现该地区的陆地下垫面上空湿度较水面大、温度较低；水面上空湿度较小，温度较高，且水面上空边界层厚度要大于陆地。作者从盛行风向、局地能量平衡、陆气相互作用等方面对实验结果进行分析，结果有助于研究和了解夏秋季节白洋淀湿地地区大气边界层特性和演变规律，为进一步认识白洋淀湿地的水循环及能量平衡提供了参考。观测结果也检验了北京大学自行研制的新型高精度温湿度探空系统的性能。

关键词: 白洋淀湿地, 高精度温湿度廓线, 大气边界层