Abstract:Based on the daily wind data of June, 1979 is calculated by an in-direct method the mean thermal field at 90°E meridional cross-section and then the mean meridional circulation (MMC) driven by hetero-geneous non-adiabatic heating with the diagnostic equation for the MMC.The numerical results are compared with those of rotating dishpan experiments and numerical experiments in general circulation as well as with analytical results of empirical orthogonal function. Both the MMC and the second eigenvector field obtained using the empirical orthogonal analysis from daily meridional circulations in June, 1979over the central Plateau are due to heterogeneous non-adiabatic heating, which shows the significant influence of thermodynamic effect of Qinghai-Tibet Plateau on early summer meridional circulation. Finally,the evolution of the MMC during the seasons of the general circulation transition in the northern hemisphere is made clear.

Abstract:The Mixed polynomial method is used to represent the meteorological field in a given latitudinal zone with a series of products of the Tchebysheff (Чебышев) polynomials and the trigometrical functions.This method manifests many of the advantages that could be obtained the Fourier series, the Tchebysheff polynomials and the spherical harmonics. In this paper the contour field is represented by this method and then the accuracy of the representation as well as the application of this method to the researches of the atmospheric circulation is discussed in some detail.

Abstract:Two problems are discussed in two-group discriminant analysis.One is the application of Mahalanobis distance in discriminant analysis along with its necessary conditions. The other is an illustration of calculating the quadratic discriminant function.

Abstract:With the help of a two-level model the effect of releasing condensation latent heat on the flow field in the geostrophic adaptation process is discussed in this paper. It is shown by theoretical analyses that the release of latent heat makes a contribution to the formation and development of the low-level jet stream and cyclone.

Abstract:With the data taken from five experiments in a 2-year period it has been found that a Model 711-storm-detecting-radar could determine rain intensity more accurately at a single location at a short distance if data of acumulative amount of water during the longest possible period of time were used. A comparison is made between the values of the radar constant C obtained by two methods. It is suggested that a storm-detecting station is able to find out the value of C by means of data from a self-recording rain gauge.

Abstract:The echo features of the torrential rain occurring in the JiangHuai area, Anhui province, during the Plum rain season of 1980 are analyzed. It is found that the echoes are of a combined type of convective cloud belt or crowd mosaicked in the stratiform clouds and the precipitation mechanism of this torrential rain is very similar to that of the tropical convective precipitation. Most probably it is substantially a kind of severe rainstorm resulting under the action of the low-level convergence when the tropical air masses move north-ward. Thus a physical model for the torrential rain in the Plum rain season is presented.

Abstract:A study is made of Z-I relationships in various types of rain based on 437 raindrop spectra from Hunan and Anhui. It has been found that (1) the statistical results of the Z-I relationships according to rain types appear to be more reasonable than those of any obtained through reflecting factors Z and rain intensities I: (2) Z-I relationships differ in the significance for different kinds of rain and can not be replaced by each other; and (3) Z-I’s in convective precipitation over the provinces show no differences in significance.Finally, discussion is made as to the properties of Z-I’s in various cases of precipitation, the effect of various time intervals (they vary from 5 min. to 30 min. space. ) between sampling raindrop distributions on statistics of the relationships together with the corresponding measurement errors.

Abstract:Based on the experimental data of several seedings in two consecutive years an expression is proposed for autumn cooling index for hybrid rice. An analysis in made of the cause and trend showing the variation of the index, according to which is presented the demarcation of the index for rice-growing regions in South China, and this of value for agricultural purpose.

Abstract:Climatic condition is an important factor that may greatly affect the delineation of hybrid rice growing areas and its yield. Based on the data from nation-wide coordinated experiments, analyses are made of time and space variations of hybrid rice growth periods and the difference in the structural elements of yield for various rice growingareas. And climatic indices of structural elements of yield in different areas are computed in order to provide an agroclimatic basis for the delineation of hybrid rice growing areas.

Abstract:It is proved directly from the definition that μ_A μ_B has a convex fuzzy grade on the assumption that each of them is of such grade. By examining them in various cases and giving a proof for each case an expression is proposed for the convexity of μ_A μ_B, which is appropria te to the general case.