午夜欧美大片免费观看,欧美激情综合五月色丁香,亚洲日本在线视频观看,午夜精品福利在线

Urban heavy smog is a serious environmental problem. Based on the field observation in Beijing from November 1 to December 20 of 1999, differences between heavy smog and fog are analyzed, and the structures of the atmospheric boundary layer for heavy smog and fog are discussed. Some results are founded. For example, heavy smog and fog can be distinguished from visibility, relative humidity and long-wave radiation equilibrium. The differences of heavy smog and fog in physical and chemic natures induce the boundary layer profile differences in relative moisture, inversion layer, wind speed, vapor, etc.