On the basis of introducing the basic categories of atmospheric refraction and their existing conditions,the forming processes of three kinds of atmospheric ducts are expounded.Several main characteristics of atmosphe...On the basis of introducing the basic categories of atmospheric refraction and their existing conditions,the forming processes of three kinds of atmospheric ducts are expounded.Several main characteristics of atmospheric duct are summarized and analyzed,and field sounding data from the WEstern North-Pacific cloud-radiation EXperiment(WENPEX)and meteorological data around the Xisha sea area are used to validate these characteristics.Meanwhile the sensitivities of the evaporation duct height to the variations of atmospheric humidity.the air-sea temperature difference.and horizontal wind speed are examined.With the analysis of the effect of atmospheric duct on the propagation of electromagnetic wave.the maximum trapped-wavelength and the critical emitting angle of elevation for electromagnetic wave which can form duct propagation are derived. At the same time the four kinds of necessary conditions for electromagnetic wave to form duct propagation are brought forward.The effects of atmospheric duct on ultrashort wave propagation, radar observation.short wave communication etc.are also discussed.展开更多
基金This work is supported by the National Natural Science Foundation of China(49794030),the 1999 Science Foundation of China Meteorological AdministrationJilin Provincial Government Joint Laboratory for Weather Modification,and the National Key Program
文摘On the basis of introducing the basic categories of atmospheric refraction and their existing conditions,the forming processes of three kinds of atmospheric ducts are expounded.Several main characteristics of atmospheric duct are summarized and analyzed,and field sounding data from the WEstern North-Pacific cloud-radiation EXperiment(WENPEX)and meteorological data around the Xisha sea area are used to validate these characteristics.Meanwhile the sensitivities of the evaporation duct height to the variations of atmospheric humidity.the air-sea temperature difference.and horizontal wind speed are examined.With the analysis of the effect of atmospheric duct on the propagation of electromagnetic wave.the maximum trapped-wavelength and the critical emitting angle of elevation for electromagnetic wave which can form duct propagation are derived. At the same time the four kinds of necessary conditions for electromagnetic wave to form duct propagation are brought forward.The effects of atmospheric duct on ultrashort wave propagation, radar observation.short wave communication etc.are also discussed.
