ON THE DEVELOPMENT OF IONOSPHERIC E_s-s OVER WUCHANG,CHINA AND ITS RELATED FACTORS

In this paper,data of ionospheric E_s-s over Wuchang,China are analyzed and theoretical investigation are made.It shows that:(1) The occurrence of E_s-s is in proportion to a factor K=1/G(f⁰Ef_min (2)The occurrence of E_s-s is also clearly influenced by the power of the equipment used.(3)E_s-s seems to be a phenomenon in non-magnetically disturbed days,which is due to the fact that the observability is limited by the high f_min in disturbed days.(4)Proper related phenomena exist both as "the prelude" and "the postlude" to the occurrence of E_s-s over Wuchang.Generally,there also exists stratification due to acoustic gravity waves.Judging from these and other ionospheric features over Wuchang,the lunar effect may serve as a common source.