Abstract:The widely used techniques for estimation of precipitation with satellite data are comprehensively presented. Some data in the published papers are used to analyse and compare these techniques. The problems in solving precipitation estimation are discussion.

Abstract:Based on the ECMWF data in summers of 1983,1986 and 1991,authors diagnostically analyze the features and physical causes of drought events over North China and flood events over the mid-low reaches of the Changjiang River. The results show that two patterns of the potential verticity field exist. One can be called "the blocking pattern"(1986),the other is "cold vortex pattern "(1983 and 1991). In addition,it is obvious that the features of water vapor transport and apparent heat sources of atmosphere vary during the different drought/flood periods.

Abstract:In order to understand the effect of the twice artificial precipitations by air-craft in 1990,the non-parameter techniques by W-M-W(Wilcoxon-Marn-Whitney)and Wilcoxon are used. The results show that the rainfalls vary in great amount between the plume area and non-plume area in 3 hours since operating. And the significant variations are also found in the plume area between 3 hours after and 3 hours before operating. Therefore,it is easy to understand that artificial seeding brings out the significant increment of rainfall. The rainfall inhencement are estimated quantitatively.

Abstract:The number of ice crystals generated from lg liquid Nitrogen was determined in a cloud chamber. The average is 1012. g-1. It is nothing with air temperature that liquid Nitrogen can generate ice crystals.

Abstract:The physical performance of OTC-1 open top chamber is evaluated. The results show that the control of the input CO2 is stable and the horizontal and vertical distribution of CO2 density in the chamber is homogeneous when CO2 density is different. With the conditions of ventilation and nonventilation, the distributions of temperature and humidity in the chamber are basically similar. And the C-filter is working efficiently.

Abstract:In order to understand the performance of T₄₂ NWP and the efficiency of its products,the comprehensive analysis is made on the parameters obtained case studies of T₄₂ prediction products in 1992. Meanwhile, the investigations on the evolution of the large-scale circulation and its adjustment are taken and the significant weather processes are taken into account. The results show that the 96-hour and 120-hour forecasts by T₄₂ model are reasonably reliable for the motions of the atmospheric long wave and extra-long waves. They are considered to be valuable for the medium-range forecasting of the tendency and trend related to the evolution of the large-scale circulation. The model is better working in forecasting of the westerly belt circulation than in prediction of the subtropical circulation. However,the significant distortion appears when the model is used for forecasting of the southern frontal area and its formation and extinction. This is the key point when the model is improved.

Abstract:Based on the analysis of the Features with the physical quantities of the relative parameters 5 days before the explosive development of the cyclones over the Northwest Pacific in winters during 1975-1988,it is found out that the locations of the explosive cyclones are related with the disposal of the ultra-long wave,long wave and the location of the westerly jet center in the middle-up troposphere. The studies lay a solid foundation to improve the medium-range forecasting. The forecasting rangs can be extented longer with NWP products.

Abstract:The temporal and spatial characteristics of the onset of the summer monsoon rainfall and the shift of the rain belt over East China is analysed based on the dekad rainfall data at 41 stations from April to September in 1991. The distribution patterns of the summer monsoon rainfall arediscussed using empirical orthogonal function (EOF) and its 20 to 30 day'low-frequency variability is also discussed. The difference between the rainfall distribution patterns in flood years and that in drought years in the Jianghuai area is considered tentatively.

Abstract:The meteorological satellite data of sea surface temperatrue are handled with computer. The three-dimensional distribution of the sea temperature is plotted. The law of the movements of cold and warm water masses which affect the aquatic products industry in Changhai County are found out. The masses are classified, which is considered as the important scientific reference to the aquatic products industry.

Abstract:The meteorological data are accumulated and compounded to "heat index, drought index and water-logging index ", which can represent the calastrophic meteorology in Heilongjiang Province. In this case,the effects of the chilly injury,drought and water-logging damage are considered for the crop yield forecast. The indices can be used to eliminate the average error calculated from the multi-point meteorological data and increase the efficiency of the meteorological data. The test in 1990 (a pumper year)and 1991 (a heavy water-logging year)show 2. 62%. In July and August 1991,an error at a rate of the crop yield was predicted two and three morths ahead respectively, the average accuracy was above 95%.