Abstract:Based on the climatological calculating methods proposed in this paper, the net radiation, as well as the components of radiation balance, is computed for 223 stations throughout China and their distribution patterns are analyzed graphically. It is found that high-value centers of net radiation appear steadily in both the south of the Qinghai-Tibetan Plateau and the east of Inner-Mongolia while low-value centers in the Sichuan Guizhou Plateau. Annual variation patterns of net radiation in different places, especially the month when the peak value occurs, are closely associated with the coming time of the rainy season. The components of net radiation obtained from calculation have relative errors, on the average, of 2.7% for the global radiation, 4.0% for the surface albedo, 9.4% for the effective radiation, and 8.9% for the net radiation, respectively.

Abstract:The effects of three ideal types of terrain on clouds which move with ambient wind have been simulated by using a two-dimensional slab-symmetric warm cloud model. A simple technique of terrain processing is used. And the results of this modeling are fairly consistent with observations.The modeled clouds moving over isolate mountains or into mountain areas undergo some enhancement, with larger amount of rainfall, whereas those moving out of mountain areas become weakened a lot. The effect of terrains is more obvious in the early developing stage of the clouds.The downdraft of the local circulation formed because of the heating of the mountain slope has a slight negative effect on the development of the approaching clouds.

Abstract:Based on dynamical energy transport and thermodynamic energy balance in the earth’s atmosphere-ocean system a steady two-dimensional climate model with residual circulation is proposed. In the model, some important physical processes with feedbacks such as ice cap-albedo, water vapor-temperature, etc. are included. The simulated steady temperature field is very close to that of the real atmosphere. Numerical experiments show that doubling of the atmospheric carbon dioxide results in temperature increase of 1～2℃ at the low latitude surface and 6～8℃ at the high latitude surface. It is shown that a 6% decrease in the solar constant is required for the -10℃ ice edge to move from its present latitude～70°to～50°.

Abstract:From the view point of biological innate nature and chemical dynamics, rtumerieal models for unitary bio-population increase and decrease including dissipation and growth are the oretically derived. The limits to which they can be applied are also defined.

Abstract:This paper presents a diagnostic study of typhoon over the South China Sea in the early summer by using the kinetic energy budget equations in a quasi-Lagrangian coordinate frame with the major results as follows: 1) The kinetic energy due to the cumulus cloud convection is the main source of energy for typhoon, which intensifies when the kinetic energy from the internal source is greater than the dissipation energy from the external source, and vice versa. 2) The effect of the baratropic energy conversion is very small, whereas the energy due to the baraclinic energy conversion is quite important. 3) The interaction between the typhoon over the South China Sea and the environment is considerable. The typhoon transports enormous quantities of kinetic energy to the environment. This process is accomplished main in the mid—upper troposphere. 4) So far as the energy budget is concerned, the CISK mechanism plays an important part in the development of typhoon over the South China Sea.

Abstract:Low frequency components with a period of about two weeks were obtained in the 500 hPa geopotential height perturbation field along 90°N-70°S during the period of July-September, 1980-1983 by using the band-passfilter. On this basis, an analysis was accomplished on the geographical distribution, activity system and teleconnection of the quasi-biweekly oscillation.

Abstract:A new method and its application to the tracking of radar echoes are presented. As it contains factors of both correlation coefficient and echo brightness reflecting the characteristics of echo structure and brightness, the method can be used to track radar echoes with great accuracy.Numerical simulation indicates that the precision of this method is very elose to that using only the correlation coefficient in the uniform wind field, and higher than that in the nonuniform wind field.

Abstract:Radiosonde data at great heights and parameters of enhanced infrared images over the Changjiang-Huaihe reaches during the Meiyu (plum rain) season are fed into an improved time-dependent one-and-one-half-dimensional cumulus numerical model. Simulation shows that rainstorm clouds associated with the Meiyu front are formed and precipitation falls in several "up-down cycling processes". It is probable that self-organization—oscillation is an important mechanism in the process of steady rainfall. A simple method using the output rainfall of the cloud model to estimate the total areal rainfall amount over different periods within 24 hours is suggested. Results show that this cloud model is of much help in the study of the macroscopic development of the rainstorm clouds associated with the Meiyu front and the estimation of the rainfall amount.

Abstract:The split explicit integration scheme for the barotropic primitive equation model is investigated for the stability and accuracy. The governing equations are divided into two sets:advective equations and adjustment equations. The integration cycle is split into two main steps. First, the advective equations are integrated explicitly, and then the adjustment equations are integrated explicitly. It is proved that the split explicit integration scheme is in more stability than the explicit integration scheme. For the limited-area barotropic primitive equation model the computing time required for this scheme to produce 24-hour forecasts is only half of that for the explicit scheme.

Abstract:Continuous soundings were made near the mountainous area in the vicinity of Beijing for the lower-atmosphere temperature structure by using a monostatic acoustic sounder. The relationship between the facsimile records and the surface wind speeds has been analyzed. It is found that the inversion uaually assumes a multi-leveled structure under the influence of the geography. Based on the facsimile records a discussion is made of the relationship between the occurrence of the convectively mixing layer and the evolution of the inversion above it. A survey is finally made for further research on the atmospheric boundary layer using the monostatic sounder in China.

Abstract:A meso-scale analysis is made of the satellite pictures showing the process of a severe hailstorm over Jiangsu on May 19, 1983. The occurrence, development and motion of the hail clusters as welt as the envitoning cloud field responsible for the hailfall are examined and characteristics of this hailstorm are discussed in detail.

Abstract:In this paper, a spectral analysis of winds by using data from the ECMF during the period of May-August 1982 has been performed. It is found that the perturbations in the ITCZ over Northwest pacific show no relation in quasi-biweekly oscillation with the activities of the cold air over Australia. The variance of the cross-equatorial currents is caused by the perturbations in the ITCZ. The oscillation of the cross-equatorial currents spread from east to west. Synthetic analysis shows that the intensification of the cross-equatorial currents is caused by the typhoon occurring in the northern hemisphere but has little relation with the cold surge in Australia.

Abstract:Multiple and stepwise equations are established with weather radar data in Jiangsu province. Comparison is made between the equations used for the accuracy of distinguishing hail clouds from others. Test of these equations with newly-collected data (1985) at other locations in Jiangsu and data (1979-198t) in cities of its adjacent provinces shows that the seequations can be used at radar stations in Jiangsu with rather good results. However, care should be taken when they are used for hail cloud discrimination in the adjacent provinces.