Abstract:In terms of 38 Year′s(1959—1996) monthly runoff data of Changmabao,Yingluoxia and Jiutiaoling Hydrological station which represent three main inland rivers in Hexi area respectively,the anomalous percentage of runoff and its degree of high/low flow were analysed.The runoff drought index was specified by processing runoff normally and its grades of dryness/wetness was divided.Considering of the drought index grades and the situation of agriculture irrigating,some reasonable suggestions about irrigating were given.

Abstract:The tropical cyclone motion is affected by many factors,such as the internal structure,the atmospheric temperature and the land conditions.However,the pressure gradient force of the environmental field and the internal force of the tropical cyclone are most important.The general solution of governing equation of the tropical cyclone motion is derived assuming the variation of these forces is linear with the time.Also the three basic rules of the tropical cyclone motion are derived from the general solution of governing equation.Some achievements in scientific research of tropical cyclones can be verified through the calculation and analysis the general solution.

Abstract:By using the satellite cloud pictures,Doppler radar and lightning information,two cases of lightning strokes were analysed in Beijing area during the summer of 1998. The result shows that local convection cloud growing cause strong storm activity. There are closer relations between electrification and convection process of thunderstorms. The lightning data is a useful tool in short range forecast. It can monitor development and evolution of convective system.

Abstract:Based on weather charts,satellite data,surface precipitation data,GPS,specially the Particle Measuring System(PMS) data,etc,obtained in the cold vortex system in North China,in May 17—18,1999,some features for this type of system were concluded as the fowlloing.①The precipitation process was due to the meeting of the Huabei cold vortex and the shear line system along the Changjiang River.②The precipitation clouds can be divided into two layers,and there is a dry layer among them.In the cloud body,the supercooled water content is low(0.035g/m³),and its distribution is not even.Due to the existence of the dry layer,the rain droplets evaporate after leaving the clouds.③The maximum cloud particle concentration is 250/cm³.The cloud particle diameter and concentration are not uniform in the cloud.

Abstract:A new era in operational numerical weather prediction(NWP) began in recent years when the ensemble predictions were performed in some meteorological centers in the world.Since the actual state of the atmosphere at any time is known only approximately,a complete description of the weather-prediction problem should be formulated in terms of the time evolution of an appropriate probability density function in the atmosphere′s phase space.Ensemble forecasting appears to be the only feasible method to predict the evolution of the atmospheric probability density function beyond the range in which error growth can be described by linearized dynamics.The generation of effective perturbation is one of the major problems in ensemble forecasting.Perturbing the initial conditions along the most unstable directions of the phase space of the system is a technique which may be most effective for determining the principal weather types consistent with given initial data.The singular vectors and Chinese ensemble prediction systems were described briefly.

Abstract:The ensemble prediction products,its present situation of operational use,and the future were summarized.

Abstract:The parameters of the heavy rain intensity were calculated by using the numerical step by step method and the least square method as well.Based on this and according to the structure and module programming principle,the mathematical mode was designed and the calculating system of heavy rain intensity was consquently developed.

Abstract:For the prediction′s requirement,the forecast of 2-m temperature and 10-m wind in Beijing area were developed with a nonhydrostatic mesoscale numerical forecasting system,which is developed by the National Meteorological Center and Beijing Meteorological Bureau.Quantitative forecast validation results show that the system runs successfully not only in general forecast but also in special weather.It predicts daily variation of wind direction in Beijing area successfully.Compared with eta model of NCEP,system′s prediction errors of temperature are similar and errors of wind speed are better.

Abstract:A dynamic similarity method based on the dynamic development of the atmospheric circulation was applied to the quantitative precipitation forecast.Three-dimensional and pluralism features were collected.By two grades of similarity standard,the most similarity case by mapping the ECMWF products with the history data was found and applied to the quantitative precipitation forecast in the upper reaches of the Changjiang River.The method was proved effective.

Abstract:The Chinese and Foreign language core journal of meteorology(atmospheric science) was evaluated by the method of citations,abstracts,and impact factors et al.and different evaluation methods were compared while the selection of database was discussed.

Abstract:By using of satellite water vapor imagery,the IR picture and conventional observation,the convective system on the edge of subtropical high in the east of Shandong Peninsula in 10 August 1998 was diagnosed.The results show that these factors,such as the upper week cold air intrusion,weaking and moving to the east of the northwest edge of subtropical high,the 850hPa wind convergence on the edge of subtropical high and the convective instable atmosphere structure over Shandong Peninsula,were beneficial to development of the convective system.The convective systems occurred both in the brightest area of the satellite water vapor imagery and in the wester end of the convective clouds of the IR picture.

Abstract:By using of an hourly precipitation of 162 heavy rain days at 11 stations of sanming city,Fujian province in May and June from 1980 to 1998,the spatial and temporal distribution,moving features,precipitation process and influential system of rain cluster and severe rain cluster in heavy rain days of flood season,as well as topographic effect were analysed.Some features and active regularity of the medium scale precipitation in sanming city were described.

Abstract:According to the experience and test of snake farm.The artificial culture index of temperature and humidity in different stages of snakes breeding are found.These technical parameters can further raise the economic efficiency of snake breeding.