Abstract:For the purpose of investigating the physical mechanism of theformation and evolution of the jet stream and the effect of cumulus con-vection on the jet. an occurrence over the southern part of China in thesummer of 1983 is simulated by using a limited-area five-layer primitiveequation model. A preliminary analysis is made of its characteristics, themass adjustment in the area and the contribution of cumulus convection.

Abstract:A two-dimensional stationary model is used to examine the dynamiceffects produced by air flow over the surface which experiences a suddenchange in roughness. Results from the finite element numerical solutionshow that the mean velocity and turbulence structure are quite differentfrom those over homogeneous surface.

Abstract:This paper presents a coupling computation method for winter wheatdry matter and leaf area index during the stage from three leaves to head-ing in the southern part of China based on observational data. Examinationsshow that the method has satisfactory results.Besides, initial sensitivitytest indicates that seedling growth exerts no great influence on the drymatter and leaf area index in the later growing period.

Abstract:Through natural orthoginal expansion and typical correlation anal-ysis, a statistical model for restoring the Eurasia general circulationfield is established. For this purpose, the weight coefficient field isalso restored.By using the real-time observational data from 1951 to 1980,examination is made on the effects of the restored 500hPa monthlyaverage height anomaly field in January, April, July and October of thesame years so that a certain reference information is provided for restor-ing the Eurasian general circulation field in the historic periods.

Abstract:By using the similarity theory and turbulence semi-empirical theory,a one-dimensional stationary atmospheric model over sea is presented,in which the wave effects are introduced in terms of Charnock’s empiricalformula.It has been shown that the model results resemble basically theAMTEX’75 observed results.The characteristic parameters of the atmos-pheric boundary layer over sea in neutral and unstable conditions arecalculated.

Abstract:Presented in this paper is the gray classification which is applied tothe atmospheric environment quality assessment. It is shown throughcase calculation and in comparison with other methods that this is aneffective one for assessing the quality of the atmospheric environment.

Abstract:A digital model, which can be used to predict the path of severeconvective weather events in three hours, has been established by em-ploying the digitized radar data. The model can be run on the IBM-PCcomputer and the compatible computer as well, with the advantages offast speed, fine flexibility and good universality. Significance tests inthe prediction of three typical weather events show that the model isquite effective.

Abstract:A software design of the digital data for the conventional radarnetwork is described in this paper, including the data format of a singleradar, the transformation of radar local Cartesian coordinate to map pro-jection coordinate, and the principle and flow chart of the quasi-real-time software.A model of the East-China raoar network based on theIBM PC/XT microprocessor is also introduced.

Abstract:An observational system for five-level wind speed, temperature,humidity and three-level wind direction is introduced in this paperThe data sampling and processing are conducted on an Apple-Ⅱ micro-computer and the sampling time is 10 seconds.The work consists of theprogram design and the measurement of humidity with the psychrom-eter.For ensuring accuracy the psychrometer coefficient A is remeas-ured and the errors in humidity measurements are analyzed in muchdetail.

Abstract:Based on the real-time observational data from 61 solar radiationstations, a method for climatological calculation of scattering radiationis discussed herein. Through detailed analysis of the effects of cloud-iness on scattering radiation, a semi-theoretical and semi-empiricalclimatological-statistical equation of scattering radiation is proposed,and using cloudiness data from 206 weather stations the scatteringradiation distribution over China is calculated and analyzed.

Abstract:In this paper, the structure of mesoscale precipitation in frontalrainstorm is studied over the Jaing-Huai area is studied by using themethod of time-space change and automatic rainfall records. A conceptmodel is thus established based on the relative position of the frontalsurface and mesoscale precipitation system.The relationship between themesoscale weather system and mesoscale precipitation system is revealedthrough the analysis of the hourly ground flow field, providing thecriterion for nowcasting torrential rain.