Abstract:Distributions of monthly sea surface temperature(SST) anomaly field over the equatorial Pacific and the northern Pacific have short-term climatic oscillations in the past 40 years. Analysis shows that the tropospheric geopotential heights over the Northern Hemisphere have certain effects upon the general circulation and during the first phase period of SST climatic oscillation (before mid-1970s) ,the mean height of troposphere has a falling tendency. However,during the latter phase period, it has a rising tendency. The results suggest that this kind of correlation at the upper level is better than that at the lower level, it is more stable over the low latitudes than that over the mid- and high latitudes and distinctive in the summer than that in winter.

Abstract:Ionic compositions of water soluble aerosols observed at the seashore of the Tong-gu Bay in Taishan,Guangdong Province during Feb. 1989,namely,Cl^-,NO^_₃,SO⁼₄,Na⁺,K⁺ and Mg⁺⁺ ,are analyzed. It is found that the dominant ions are Cl^- and Na⁺ ,which are of marine salt aerosol. The same origin is with Mg⁺⁺,too. K⁺ mainly comes from the continent. And SO⁼₄ from sea salt mostly. It does reveal,however,the large scale high pollution of sulfar in the continent of East A-sia. The study points out that high concentration of SO^-₃ is of 100% non-sea-salt origin. It is obvious that this is related with local farming and household cooking.

Abstract:Orange freeze injury climatic features and the law of low temperature change in the overwinter period and climatological contermine to develop orange production in Jinhua-Quxian Basin and both in the southern Part of Hunan and Jiangxi Provinces in recent 40 years are analyzed systematically. Spectrum analysis suggests that there are principal period lengths of 9-10 years of negative accumulated temperature. The frequency and the probability of orange freeze injury occurrence are the biggest in Jinhua-Quxian basin and in the southeast part of Jiangxi Province,and smaller both in southern part of Hunan and Jiangxi provinces and the northern part of Fujian. It is expected that a medium degree of freeze injury of orange to the end of century in Jinhua county will appear,and freeze injury of orange to the end of the century will not appear both in Jianxian and Hengyang county.

Abstract:Fundamentals of stepwise regression with the couple score criterion (CSC) is described, meanwhile, computational procedure and its details are exampled. A model built by this method is capable of predicting both quantity and category of a predictand.

Abstract:Comprehensive weather forecasting expert system which centres in "Intelligent Database" is a common expert system shell and an operational process. Compiled mainly using computer languages such as Turbo-C,Turbo-prolog and Basic etc. ,this system consists of six major parts:objective analysis and system distinguish,intelligent database including real time and history,analogous process prediction based on the moving evolution of major weather system,physical element diagnosis,experience forecasting and comprehensive decision. Every part is relatively independent but all parts can be combined executing together. As an applied advanced technology, the system has a complete function and a rational structure design.

Abstract:The design method and technical feature of the Image Processing and Application Information System are presented. Besides, various ways to display remotely sensed image on the microcomputer screen with the support of the system's software will be presented in detail.

Abstract:The physical factor fields and the behavial law of mesoscale geographical convergence over the northeast of Qinghai-Xizang Plateau are analysed. The relationship between the convergence and the dry/wet periods and heavy rain over the boundary slope of the Plateau are also discussed.

Abstract:Based on the data two-times a day in 1980-1991 for the Duchang evaporation-station, the differences of water-surface evaporation and discount coefficient between day and night for small type evaporation pan are analyzed and comparisons with that for the E₆₀₁-type evaporation pan are also made. Moreover, features and existing questions of water surface. evaporation for the small-type evaporation pan are revealed,and improving suggestions are also proposed.

Abstract:The concept of helicity,defined as the inner product between streamwise vorticity and storm relative winds,has been reviewed. Six cases of severe convective storms over Beijing area are presented to acquaint the forecaster with a range of expected values. The results indicate that helicity may serve as a forecast parameter for severe convective storms.