The Field Experiment of Atmospheric Boundary Layer over Heterogeneous Surface in Baiyangdian Area-Introduction and Preliminary Data Analysis
白洋淀地区非均匀大气边界层的综合观测研究——实验介绍及近地层微气象特征分析

A comprehensive field experiment of atmospheric boundary layer over heterogeneous surface is introduced.The experiments were held in Baiyangdian area of North China during 1622 November 2004 and 827 September 2005.Some micrometerological characteristics from preliminary data analysis shows that(1) the diurnal variation of air temperature over the land is more obvious than that over the water area and the wind speed over the land is less than that over the water area.In September,the air temperature over the land is higher than that over the water area in the daytime,but lower at nighttime.In November,the air temperature over the land is almost the same as that over the water area in the daytime,but is lower obviously at nighttime.Either in November or in September,the vertical speed over the water area is always negative,but over the land,there is sometimes a positive vertical speed at noon;(2) in September,the incident shortwave radiations over the land and the water area are almost the same,but the reflected shortwave radiation over the water area is much more than that over the land.The incident long wave radiation over the land is much more than that over the water area,but the reflected long wave radiation over the land is less than that over the water area.The net radiations over the land and water area are almost the same in the daytime,but there is a difference at night;(3) the albedo over the land is smaller than that over the water area;(4) in September,the sensible heat fluxes over two sites are about 150-200 W/m~(2),and the latent heat fluxes are near 300 W/m~(2) in shiny days.In November,the sensible heat flux is larger than the latent heat flux over the land,and the sensible heat flux is smaller than the latent heat flux over the water area.There are always minus latent heat fluxes over the water area;(5) in September,the water body temperature is much higher and changes more slightly than the water surface temperature.