Abstract:Diagnostic analyses of the enstrophy and the nonlinear cascade ofenstrophy are made in the wave-number domain, using data at the 500-hPa level for the summer of 1980. By comparing the results in our study with those shown by Steinberg, H. L. et al. for February-April, 1963,we find that the main characteristics of spectra distribution for summer and winter are much alike but the nonlinear exchanges of enstrophyamong waves for the two seasons are quite dissimilar. Steinberg emphasizes that enstrophy is transferred from the large to the smallerscale. Our study shows that, in summer, super-long waves (with num-ber of major waves equal to 3) supply enstrophy simultaneously to long(wave number=4-8) and short (wave number≥9) but meanwhile theshort waves transfer a great amount of enstrophy to the long waves,Ultimately, there is a net loss of enstrophy in the nonlinear exchangefor both the super-long and the short waves, with the former losingmore. And the long waves have a large net gain of enstrophy. Thus the sign of net gain or loss in enstrophy for long and short waves iscontrary to the winter case.

Abstract:Based on data from the 1979 TIPMEX with the aid of an empiricalformula. detailed study is done on the role of the plateau as a surface heatsource and the distribution of the various components of heat balanceover the plateau and its adjacent areas. Emphasis is placed on theeffect of the march of seasons on surface heating including both sensibleand latent. The principal way through which the surface heats theatmosphere and the variation of intensity of heating are revealed. Itis shown that sensible heat predominates in the dry season withmaximum intensity appearing in the west and latent heat plays amore important role during the wet months, especially in the east. Inaddition, a discussion of the magnitude and distribution of drag coeffi-cient C_D is presented and the mean value is found to range from 4·10^-3to 5·10^-3. The values are higher in the east than in the west andgreater in the valleys than on the plains.

Abstract:With an aim to obtain a continuous and homogeneous series oftemperature fields requisite for the study of large-scale atmospheric behaviour, a method for interpolation and extrapolation of temperature field series is presented on the basis of the correlation between characteristic features of temperature distributions of adjacent geographic areas along with the EOF decomposition of the field series.continuous and homogeneous series of monthly mean temperatures forthe period from 1881 through 1981 for 42 stations dispersed over China are constructed. Independent sample tests show that these interpolated series depict the main characteristics of anomalies in spatial distribution of temperature quite well.

Abstract:Whether the tetroon can be kept at the predetermined level directly affects the success of the flight. A way to determine the free lift of tetroons made in China and of releasing two tetroons at thesame time to the predetermined level is introduced.

Abstract:Analysis is made of the characteristic features of horizontal wind pulsation inside and outside wheat field with the aid of the statistical theoryof turbulence. The observational data are obtained at four different levelsat two spots, one located inside the wheat field and the other outside.The results suggest that the properties of the horizontal wind pulsationunder the canopy of the crop agree approximately with locally-isotropic turbulence theory. The time structure function obeys the "2/3 law"when τ is small(τ<20sec.). Non-dimensional spectrum at high frequencyis in accordance with the "-5/3 power law". Greater turbulivity, weakerpulsation intensity and shorter space scale are observed within thewheat stand than in the clearing. In addition, the response characte-ristics of the horizontal wind pulsation are discussed by applying asingle input linear model to the wheat stand.

Abstract:When a typhoon approaches or lands at the southeast China coast. a heavy rainfall area usually occurs over mid-latitude China far away from the typhoon center. Especially when the typhoon is accompanied by a reverse trough extending northward, heavy rain fallarea is readily found in this inverted V-shaped trough. Energy-fronto-genesis is of ten observed with this trough. An attempt is made to explain the cause of the heavy rainfall through the kinematics ofenergy-frontogenesis. ω equation for saturated air and potential tendency equation are developed, incorporating the release of latentheat. Dynamic effect for energy-frontogenesis is analyzed by meansof the moist ω equation. Finally, as an example, the energy-frontogensis function for heavy precipitation process in the reverse trough accom-panying Typhoon 7504 is computed.

Abstract:Based on data of hybrid rice sown at different times, discussionis made of the increase in the weight of dry substance in conjunction with the behaviour of the Logistic curve, and of the b-value as anindication of the length of the growth period. The notions growthspeed (GS) and relative growth speed (RGS) are introduced and it isshown that when t=-a/b, GS attains its maximum and the RGS curveshown an inflection point, suggesting that substantial change take splace around the boot stage in the growth of the rice. In addition,the variation of optimum temperature for the growth of hybrid rice andthe effect of sunlight-temperature condition on the RGS are investi-gated and corresponding relationship is expressed. Finally a sunlight-temperature model is established and results of tests by historical dataare found to be quite satisfactory.