ACOUSTIC—GRAVITY WAVES CAUSED BY AN IMPULSIVE POINT SOURCE IN THE MIDDLE ATMOSPHERE

In this paper the results of acoustic-gravity wave(AGW)are presented for an impulsive point source inthe middle atmosphere.By virtue of general function theory,the Fourier transformation function is expandedat high frequency and low frequency,respectively.Then Row‘s results are extended from the specialcondition to the general one.When we have cleverly introduced an integral with the parameter,the factor(1/ω_0 t_0)can be obtained,which has a great physical meaning.The conclusion of this paper is as follows:(1)Under special condition the,only has been obtained by approaching ofRow‘s.In the present paper any approaching need not be made in obtaining the results.Besides thethe corrective factor is gained.The less t—α—t_0 is,the more the corrective effect is.(2)Theof formula(12)in Row’s must be corrected to bewhereαis a retardant time(3)(1/ω_0 t_0)~n indicates that when t_0 is greater the corrective effect is less.Also indicates it when T_c islonger the corrective effect is more.(i.e.the lower the     

中层大气中脉冲点源产生的声重力波

本文从脉冲点源出发,利用广义函数的理论,将象函数作高频近似和低频近似,求得了早时响应和长时响应,从而将目前已有的结果由特殊推广到一般。再巧妙地引入含参变量的积分,可以得到(1/ω_ct_0)~n的因子,此因子有极其重要的物理意义。本文的结果是:1.Row是在特殊情况下作近似,只能得到本文不作近似而是在一般情况下就可得到结果。此结果除了包含特殊情况下的外,还得到了一个修正项,t-α-t_0越小,修正效应越大。2.Row的(12)式中的应改为α表示一向后的推迟时间。表示离源越远,t_0越大,修正效应越小。而ω_c越小周期T_c越长,修正效应越强,越低频率声重力波衰减愈慢而愈容易观察。4.从推导过程可以看到Row文章的(20)式不是长周期近似,而是高频近似。5.实验与理论一致。