Experimental studies on the long period changes of air-surface energy exchanges

地-气能量交换是全球大气过程的重要环节之一。以往对大气-地面相互作用的研究主要是在晴天条件下进行的，目的是检验大气湍流理论的结果。然而，为了与气候变化相协调，应评估一般条件下（如阴天或雨天）的相互作用过程。本研究的目的是在一般条件下测量空气与地面的相互作用，并探测能量交换的长周期变化。一种是简单方法的远距离观测，另一种是检验方法的详细观测，前者采用了斜杆剖面观测技术和地面辐射温度、地面湿度的连续测量，以及降水、蒸发和土壤温度、湿度的测量。为了检验这种简单方法，我们从1986年起在京都大学宇治实验场的南端进行了用激光束偏转测量空气密度梯度，并使用了用音速风速计-温度计和红外线湿度计的涡动相关方法的详细观测。详细的数据分析仍在进行中，包括详细的水分交换分析。部分结果已在报告中公布。

Energy exchanges between ground surface and atmosphere is one of the important links of global atmospheric processes. Most of the past studies on air-surface interactions were mainly made in fair weather condition to check the results of the theories of atmospheric turbulence. However, to incooperate with climatic changes the interaction processes in general condition such as coludy or rainy days should be evaluated. The purpose of the present study is, on that point, to measure air-surface interactions in general condition and detect long period changes of energy exchanges.For thie purpose, the measurement was devided into two part. One is long range observation in simple method and the other is the detailed observation to check it. For the former purpose profile techniques with lobing mast and continuous measurements of the ground surface radiation temperature and the surface wetness were made together with rainfall, evaporation and soil temperature and humidity measurements. For the detailed observations to check the simple method, the eddy correlation method with the use of the sonic anemoneter-thermometer and the infrared hygrometer together with air density gradient measurement by laser beam deflection is employed.These observations were made on the southern end of the Uji Ground of Kyoto University from 1986. The detailed analysis of the data are still under going including detailed analysis moisture exchanges. Some of the results were published in the report.