Abstract:With hourly special persisting rainstorm data from digital weather radar evaluations and gauge observations in the east of Hubei on the 20-22nd,July i n 1998, the characteristics of radar-detecting precipitation calibrated by vari ational method is studied Results prove that the radar estimations calibrated d oes not only keep the distribution condition of the rainfall before calibration, but also the errors from the comparison with gauge observations are improved re markably.

Abstract:By using 114-year typhoon data in the north west Pacific adopted Poiss ion function,the Poission distribution characteristics of the disastrous typhoon events for a century along China′s coastline from the Bay of Bohai through the South China Sea area are discussed It is indicated that the possibility for se rious typhoon hitting could be described by Poissin distribution It is also fou nd that the results are very useful for program design of city development for i ndustry and agriculture It also points out that typhoon disaster indexes obtain ed with 50 year data in the north west Pacific is coincide with Saffir-simpson indexes by 70 year data in Caribbean Sea area.

Abstract:Based on the data obtained by the Partical Measuring System (PMS) with aircraft,microphysical characteristics stage and microphysical distribution of pr ecipitable stratiform clouds of Huang-Huai cyclone are analyzed.It improved a b ases to choose the potential area.

Abstract:Summer, winter or annual temperature change of Zhejiang Province are ana lyzed with a hundred years′ temperature series data. It is found that the total tendency of the annual temperature change of Zhejiang Province is identical wit h that of Northern or nationwide. But, the time of the annual temperature ascent or descent of Zhejiang Province delays that of Northern or nationwide. It is th e main feature of warm winter that the minimum temperature in winter ascents. It is the main feature of cool summer that the summer extreme maximum temperature days obviously decrease.

Abstract:Based on the long-term observation data (1959-2000) of a meteorological station, which was set up inside the nature reserves in Xishuangbanna, Yunnan Province, the characteristics of local climate change is studied. The results in dicate that the annual mean air temperature has been gradually increasing since 1985, and with a more obvious trend in dry-hot season from March to April; meanw hile, there are some difference on increasing rate between the mean maximum and minimum temperatures; the annual precipitation attenuates remarkably with an ave rage rate of 53.0 mm/10yr from 1950 to 1990; the air relative humidity presents an obvious decreasing trend, especially in dry-hot season. The main cause of the climate change in this area is the change of tropical forest cover, combining i ts effects with global climate change.

Abstract:By forecasting and diagnosis of extraordinary rainstorm in the lower-middle reaches of Changjiang River on July 22 ,1998 and July 4, 1983, it is shown that the upper cold-air piling up left of lower jet is the main structure fe ature, diagnosis of physical parameters and its tendency shows that there are re lations between heavy precipitation or severe convection area and strong conver gence area at 850hPa to 500hPa level and strong convergence area of vapor flux in future. The rain area can be better estimated by computing the tendency than the physical parameters.

Abstract:The main influential systems,various physical features and satellite im ages were synthetically contrastively analysed.Topographic features are also co nsulted.It is shown that the two torrential rain are all caused by plentiful m iosture and instability energy conveyed by the southwest airflow outside subtrop ical high,assorted with upper trough,shear line and low-level jet.The cold fron t (″7.9 torrential rain″) or development of convection at night (″7.13 to rrent ial rain″) triggered off convective instability energy and a stronger convectio n produced.Torrential rain located in the area with convective instability,high energy tongue at the middle-low level,warm advection convergence at the low lev el and divergence at the high level and ascending motion.Topographic lift and be ll-mouthed topographic effect also affected the torrential rain.

Abstract:Based on the data of thunderstorm cloud echo obtained by 713 radar from June to July,2000,the characteristic of thunderstorm,weather situation and the a tmospheric stability are analysed.Results show that the echo top reaches 17-18km,the maximum reflectivity is 55dBz and the maximum reflectivity for most of the thunderstorm is 40-45dBz,which mainly form on the thunderstorm cloud cluster-thunderstorm short zone of level scale>30km.Like the severe weather such as hea vy precipitation,the strong wind with thunder rain and hail,the strong thunderst orm is related on the topography and from the inside of strongly developed thund erstorm.

Abstract:By using the methods of statistical analysis the data at eight observato ries of Guangdong Province is studied,and it is found that there is an approxima tely linear relationship between the daily maximum 10-minute average wind spee d and the daily maximum instantaneous wind speed.Based on the development of reg ression equation,the objective method of discriminating the two data′ accuracy and of estimating the two wind speed values are obtained.

Abstract:Kalman filter method based on the PRESS criterion and optimal subset reg ression is applied to predict the monthly average temperature in the east of Hex i area.Results show that the prediction modeling of Kalman filter method is bett er and steadier.It provides a new method for the short-range climatic prediction.

Abstract:An intelligent and automatic decision system of weather Modification at Zibo, Shandong Province, which is advancing to objectivity and automation,are built up.