Abstract:Based on the mesoanalgses of severe convective processes, the effects of largescale weather pattern on evolution of mesoscale convective storms are summed up. The characteristics of activities of severe convective storms over Beijing area,East China and Southern Fujian are found.

Abstract:The advances in researches on increasing trend of CO2 concentration in atmosphere and its impacts on plant growth and agricultural production in recent years is briefly reviewed. It is noticed that either so-called "direct effect"or "indirect impact",all have two implications, both positive and negative. Although, at present, there is a more or less general understanding of"negative larger positive", however, because of a lot of uncertainties in scientific theory and knowledges, how to synthetically estimate the impact of CO2 increase in atmosphere on plant growth and agricultural production is still a very important theme to be studied further in the future.

Abstract:The general circulation characteristics of fifty regional heavy rainstorms which are divided into four patterns in the north of China during 1954-1983 period are analysed based on the behavior of the Northwest Pacific subtropical high.

Abstract:The growing process of winter wheat is simulated by CERES-wheat model assuming the daily temperature variation to be-1℃, 0℃, 1℃, 2℃and daily precipitation change to be - 20% ,-10%,-5%,0,5%,10%,20% respectively. The case study site is of zhenjiang,Jiang-su Province, which locates in the middle east of China. The simulation results show that the impact of temperature variation on winter wheat is stronger than that of precipitation change. Warming climate can speed up the development rate and shorten the phenological period. In ge-neral,the adverse effect of climatic change on grain yield is greater than that of its beneficial effect, especially when the climatic cooling and drying. Both the temperture increase and precipitation decrease can reduce the plant extractable soil water content.

Abstract:The touch experiment of long time measurement with different CO2 concentration on soybean was made by using open top chamber OTC-1. The result shows that the influences of different CO2 concentration on soybean growth and development, mass and grain yield and photosys-thesis rate are remarkably positive effect.

Abstract:A preliminary study was conducted about the cause of split for its centre of the tropical storm 9216 at 02Z Sep. 1. A new centre was formed because of the strength of cyclonic circulation in the tropical storm trough area due to the southeasterly jet at the lower layer and the attraction and merging of a vortex. The conditions of heavy rain at Qingdao City are of abundant moisture,severe ascending air,and of the influence of the eastward motion of a longwave trough.

Abstract:Moderate rain and heavy rain elimination equations y₁, y₂ and discriminant equation y₃ of heavy rain are established with normalized sample rejection method T₄₂ model output in May-June,1990-1991. The y₁,y₂ equations decreases the forecast "Occurrence" while the weather is no occurrence,y₃ equation decreases the forecast "No"while the weather is occurrence. Conveyance using these three equations is more effective than using single one equation. "CSI"score increases obviously. Experimental forecast made in 1992 is better.

Abstract:The influence of sea-surface temperature on the path of tropical cyclone has been studied based on the sea-surface temperature field calculated from the data of 3 AVHRR IR channels of NOAA satellite. Among the selected 127 path segments,out of which, 100 tended to warm sea-water areas.

Abstract:Based on the HRC data over the global tropics from 1971 to 1983,the monthly and seasonal variation of the HRC position and frequency are studied. It is shown that zonal HRC distribution with longitudenal shift occurred over the Atlantic Ocean,while two HRC occurred over the western Pacific. The abnormal HRC is also, analysed during El Nino event.

Abstract:Based on the data obtained from 1951 to 1992,climatological features and circulation background of extremely hot are statistically analysed. The results show that the South Asia high lies northly and eastly,and a block high is built and maintained over the Siberia. Consequently,there is an important circulation background to the extremely hot weather.

Abstract:Bsaed on the recent 20-years data of urban fires and meteorological elements in Shijiazhuang City, the variation of fires and its relationship with meteorological elements is obtained. This method is used in operational forecast, which provided scientific basis for fire forecast and good results have been achieved in economic and social benefit. The relationship between fire and fohn is also discussed. A new idea in application of "effective moisture" is therefore brought forth.

Abstract:The route appraising, one of very important part in the system of meteorological route, is summerized with introduction of the specific examples, the content, method and importance of this new operational system are introduced.