Abstract:By using the average height field data at 500 hPa from April to August of 1972-1980, studies have been made on the characteristics of the circulation variation during the seasonal northward advance of the rainbelt in Eastern China. Analysis shows that the seasonal variation of thecirculation is very remarkable both during the jump and the stagnationof the northward advance of the rain belt. Although the seasonal north-ward advance of the rain belt is closely related to the seasonal northwardadvance of the circulation system, the jump and stagnation of the beltdepend chiefly upon the westward shift of the trough of Asian wave 1.

Abstract:Based on the grid point data from the ECMWF for May-September,1982 and by using spectral analysis combined with the band-filtering method, a study was made on the spatial structure and propagating characteristics of the quasi-40 day oscillations with their relation to the summermonsoon over the northern hemisphere.The possible mechanism for thelow-frequency oscillations which propagated northward was also discussed.

Abstract:Using evaporation data from ten large open waters in China, Penman’sformula for calculating evaporation from water surfaces is modified. Thenew formula can be used to estimate not only the evapotative power ofopen waters but also natural evaporative power and field evaporative ca-pacity in China if a suitable proportion coefficient is multiplied.

Abstract:Close relationships are found existing among seven strong autoteleconnections of the January SST over the globe. Of them the most significant is the ‘Indian-western Pacific-eastern Pacific-Atlantic’ zonal teleconnection at equatorial latitudes marked by the mode sign of + - -.A meridional and zonal positive correlation exists between the mid-latitude and western equatorial Pacific and between the latter and mid-latitude Atlantic, respectively. Temporal analysis indicates that the occurence of the equatorial zonal teleconnection type agrees with that of the EI Nino event and the anomalous SIO to the extent that it can be used to describe their appearance objectively and quantitatively, and to interpret the relationships among the annual anomalies in the strengthof the tropical Walker and Hadley cells, and the western Pacific sub-tropical high.Results can be an aid to understanding the low-latitude large-scale air-sea interaction.

Abstract:In this paper, 2-dimensional Walsh transform is used in the expansion and analysis of precipitation fields over the middle and lower reaches of the Changjiang River. Synoptic implications of the typical fields and their corresponding coefficients are given and formulas for the rela-tive target R² and the fitting root mean square error are derived form easuring the expansion quality.The convergence and independence ontime of Walsh transform are discussed and compared with those of expan-sion of Chebyshev Polynominals.Then the precipitation fields are ana-lysed in terms of several main Walsh coefficients. Finally, sixteen Walsh coefficients are selected to fit the precipitation fields.

Abstract:The solution to electromagnetic scattering by inhomogeneous oblate spheroidal particles is obtained for any polarized incident wave on the theories of spheroidal wave functions and average electric fields. And calculations are made for redar backscattering cross-section of a two-layered spongy ice hailstone with an arbitrary size and condition. The nucleus of the hailstone is considered as an ice oblate spheroid and the shell is filled with a mixture of ice and liquid water.

Abstract:By use of china’s drought/flood grade atlas for the past 500 years (covering 100 stations) and the WK sinking fuzzy clustering method,areas of drought/flood in China are classified into eight main types.On this basis, studies are carried out on the drought/flood cycle and trend, the classification of dry/wet Periods, and some statistical features.

Abstract:This paper is concerned with global existence and regularity properties for(E1). The main results are: if α<p-2 and u_n∈L^p(Ω), (E1)admits a global solution, which satisfies: essup|u|≤c (T, ‖u₀‖_p) for any ε>0, where Q_T,ε Q_T,ε=Ω_ε×(ε,T), Ω_ε={x∈Ω|dist{x,∂Ω}>ε}.

Abstract:Taking the process of winter wheat tillering and earing as a dynamic self-adjusting system, the cybernetic literal description of models and their corresponding mathematic models are proposed. And according tothe basic idea of dynamie programming, a preliminary study is made of the optimum control rules for the process of tillering and earing.

Abstract:Studies of the response of stomatal behavior to environmental factors were conducted. It is shown that light intensity and atmospheric vapor deficit (△e) are major factors having influence on the stomatal behavor.The diurnal trend diagram of the stomatal resistance is shaped as "W"regardless of weather types, while the maximum of the resistance atnoon its greater on sunny days than on overcast day. The whole diurnalprogram is divided into three portions: OPENING-RESPONDINGperiod, MIDNOON-REST period,and CLOSING-RESPONDING period.The diurnal shape of the resistance curve is determined by circadianrhythms and environmental factors. The resistance is higher in thelower layer than in the upper layer in the general functional formГ_s=Г₀ f(I) g(△e)…. The special forms of the individual periods are as follows: 1) OPENING-RESPONDING period and CLOSING-RESPONDINGperiod Г_s=Г₀ exp(-a₁I) (1+b₁△e) 2) MIDNOON-REST periodГ_s=1/2{ [(Г_max-Г_min)/2] cos (2π(t-t₀)/T)+(Г_max+Г_min)} exp(-a₂I) exp (b₂△e)

Abstract:In this paper the turbulent diffusivities K are established by dimension analysis in terms of turbulent spectrum, and the radiation euqation with greater precision is cited. The time-dependent relationships between thermal factors are investigated with the PBL numerical model.

Abstract:The characteristics of the general circulation at 500 hPa over the middle and lower latitudes of Asia during June were discussed with relation to the wet/dry Meiyu season in the northern part of Zhejiang province, thus leading to the long-range forecasting of the wet/dry Meiyu season by using the characteristic values of the general circulation in March. It is found that the wet Meiyu season is characterized by "X" and"V" patterns of the is allohypse field at 500 hPa during June, while thedry Meiyu season by "M" pattern, showing a sharp contrast. Good resultshave been proved by using the characteristic values of the March circulation to forecast the wet/dry Meiyu season.

Abstract:In order to apply the professional knowledge and practical experience of forecasting experts to daily operational weather forecasting and to solve the problem of the knowledge accumulation, an advisory weather forecasting expert system has been designed and its current frame developed by use of the new TURBO-PROLOG Language on the IBMPC/XT micro-computer. It has been run satisfactorily after importing the expert experiences about cold wave, hailstorm and sea breeze. Re-sults show that it has reached the subjective forecasting level of experts.