Abstract:Jn this paper,some achievements in the research on large-scale atmospheric dynamics are reviewed.

Abstract:In this paper,the selfrecording data over denser surface are used to analyse strong surface wind and its fluctuation in the process of typhoon-caused severe rain corresponding with the genesis and movement of the rain clusters in downstream as well as oscillation of rain intensity.The values of nonlinear terms in the divergence and vorticity equation are computed.Local variation of the divergence caused by the inhomogene-ous distribution of the surface wind velocity and the effects of interaction between vorticity field and divergence field on trigger process of mesoscale system of severe rain are discussed.Finally, it is also pointed out that it is helpful to be knowledyed of the feature and variation of surface wind field in order to catch of mesoscale system of severe rain and to make the short-time forecast of it.

Abstract:In this paper,the loss of AgI aerosols in the operative clouds has been calculated,it shows that the wash-out by rain is not neglectful. Therefore it is most important to increase the throwing height of the anticraft gun shells and to locate the AgI aerosols into the upwind regions of the clouds in sense of precipitation enhancement or hail suppression.

Abstract:In this paper,the effectiveness of accumulated temperatures in the western mountain areas and eastern areas of China over the sub-tropical regions is intercompared. The results show that the ineffective accumulated temperature appeas less in the western mountain areas but effective accumulated temperature occurs more frequently than or equal to those in the eastern areas.The period of day temperature in the western area is more suitable for growing of sub-tropical flora.The equiva-lantly accumulated temperature is 500--1000℃ higher than the actualone in the western mountain areas.Finally, the index of demarcating line of sub-tropical northwest areas is given.