Current Issue

• A SUCCINCT NUMERICAL METHOD TO SOLVE THE SCATTERING PROBLEM OF LARGE NOSPHERICAL PARTICLES
• Yang Ping;Cai Qiming;Xu Baoxiang
• 1989 Vol. 8 (4): 291-300. 
• Abstract ( ) PDF (1169KB) ( )
• For the scattering of unpolarized natural light transfering in real atmosphere, the scattering parameters about which we are concerned are usually the intensity of scattered light and degree of linear polarization. In this paper, based upon the statistics about the scattering probability of photons along randomly sampled incident routes, a succinct numerical method has been developed to compute the phase function and degree of polarization for the single scattering of light by polydispersive large particles. The difficulty related to divergence, when the surface of scattering particle is curved, has been avoided by this numerical method. Meanwhile, because the shapes of water droplet in atmosphere are often spheroids approximatively, the scattering characteristics of spheroidal water droplets have also been discussed.

• THE PRELIMINARY STUDY OF EFFECT OF ENVIRONMENT FLOW FIELDS ON MOVEMENT OF SOUTHWEST VORTEX
• Chen Zhongming
• 1989 Vol. 8 (4): 301-312. 
• Abstract ( ) PDF (729KB) ( )
• In this paper, Southwest Vortex is regarded as a sub-synoptical scale disturbance in environment flow fields. The equations describing sub-synoptical scale disturbance are applied to a simple two layer model. According to some feature of the Southwest Vortex, the equations are simplified by making some approximations. The vector C indicating movement feature of the Southwest Vortex in lower troposphere is obtained by solving the equations. Using the diagnostic equation (35), the main factors which influence the movement of Southwest Vortex are discussed and some qualitative results are obtained. Finally, a case study of process of movement of Southwest Vortex is made by using these results.

• KINETIC ENERGY BUDGET OF THE MOVING EASTWARDS AND DEVELOPING LOWS ON THE QINGHAI-XIZANG PLATEAU IN HIGH SUMMER
• Sun Guowu;Chen Baode;Wu Jicheng;Liu Donghan
• 1989 Vol. 8 (4): 313-320. 
• Abstract ( ) PDF (508KB) ( )
• Some analyses show that the Plateau vortexes either move eastwards and develop or disappear localy depending upon the effects of different environments on the vortexs. So in this paper, the kinetic energy budget of Plateau lows of both moving eastwards for three cases and local disappearnce for two cases were calculated. This kind of analyses is useful for both synoptic and numerical forecating.

• NUMERICAL EXPERIMENT ON THE FORMATION MECHANISM OF A SW VORTEX IN SUMMER
• Fu Meijuan;Liu Fuming;Shen Rujin
• 1989 Vol. 8 (4): 321-330. 
• Abstract ( ) PDF (693KB) ( )
• The formation mechanisms of a SW vortex were investigated with numerical experiments using a simplified hydrodynamic meso-scale model suitable to Qinghai-Xizang Plateau in this paper. The results of control experiment show that the vortex forms over the eastern flank of the Plateau near 3000 m contour, and is consistent with the observed. The distribution of rainfall zone is also reasonable. Based on different model experiments, it is found that the dynamic process is essential for formation of the SW vortex and that the latent heating plays an important role in its maintenance and development. Without the releasing of latent heating the vortex would tend to degenerate. Sensible heating has just a little function in the vortex formation. The Qinghai-Xizang Plateau exerts significant effect on formation of the SW vortex. When the model orography height is reduced by half, the simulated SW vortex is located to the southwest of that in the control experiment. The experiment without orography reproduces a heat low at 700 hPa in the east part of the Plateau only.

• THE RADIATION STATE OVER THE EQUATORIAL AND ITS SURROUNDING SEA REGION IN THE WEST PACIFIC IN AUTUMN 1986 AND 1987
• Yao Lanchang;Yuan Fumao;Chen Youyu;Liu Junyi
• 1989 Vol. 8 (4): 331-344. 
• Abstract ( ) PDF (853KB) ( )
• In this paper the state of the solar radiation is analysed by the short-range radiation data observed in autumn 1986 and 1987 over the equatorial and its surrounding sea region in the West Pacific. Some characteristics of solar radiation over the equatorial and its surrounding sea region in the West Pacific are then revealed.There is no doubt that it will be very helpful for us to understand the heating state above the surface between sea and atmosphere as will as the influences of weather and climatic upon the equatorial and its surrounding sea region in the West Pacific.

• THE SEASONAL VARIATION OF THE SECULAR MONTHLY MEAN MERIDIONAL CROSS-SECTION AT 50 hPa LEVEL OVER THE NORTHERN HEMISPHERE
• Qu Zhang;Chen Fang;Zhang Haijun;Zheng Guang
• 1989 Vol. 8 (4): 345-350. 
• Abstract ( ) PDF (403KB) ( )
• In this paper, according to both the charts of averaged latitude-time of height at every 10°longitudes and the tables of averaged longitudinal height gradient taken over 20 years (from January 1965 through December 1984) on 50 hPa the following conclusions were drawn: ① For the seasonal variations of the circulations from winter to summer on the 50 hPa level over Northern Hemisphere, the earliest ones occur on about 90°E and 170 °E longitudes over both the northern belt (60-90°N) and southern belt (10-30°N) and in March-April. It is one month earlier over above areas than all longitudes of the middle belt (30-60°N) and the rest of both northern and south belts. ② For the seasonal variations of the circulations from summer to winter, the earliest ones occur over northern belt and in July-August; the next ones, over middle belt and in August-September; the southern belt is much more late than northern and middle belts. ⒔The seasonal variations from winter to summer at 50 hPa level start with both the Pole and Equator sides simutaneously; but the ones from summer to winter start with only the Pole side.

• ANALYSES OF THE DEPTH OF PLANETARY BOUNDARY LAYER AND ITS CHARACTERISTICS OVER TIBETAN PLATEAU UNDER NEAR-NEUTRAL CONDITIONS
• Wu Jingzhi;Li Dinghua;Hao Suming
• 1989 Vol. 8 (4): 351-356. 
• Abstract ( ) PDF (342KB) ( )
• In this paper, utilizing the conventional meteorological data during the period of May-August of 1979 and three kinds of definition methods of planetary boundary layer ( PBL), the depth of the PBL over the Tibetan Plateau in summer was calculated. The result shows under near-neutral conditions the averaged depth of the PBL over the Plateau in summer is about 600 m.

• AN EXPERIENCE IN FORECASTING HAILSTONE SIZE BY USING MORNING'S SOUNDING DATA
• Zhang Xixuan
• 1989 Vol. 8 (4): 357-359. 
• Abstract ( ) PDF (188KB) ( )

• DISCUSSION ABOUT SEVERAL CONCEPTS IN ATMOSPHERIC DYNAMICS
• Zhu Xun
• 1989 Vol. 8 (4): 360-364. 
• Abstract ( ) PDF (321KB) ( )

• THE ATMOSPHERIC PREDICTABILITY AND THE DESIGNING OF ATMOSPHERIC MODELS
• Yang Chengbing
• 1989 Vol. 8 (4): 365-369. 
• Abstract ( ) PDF (395KB) ( )
• In the paper a basic principle for designing numerical forecasting-the predictability of model's atmosphere must be consistent with the predictability of actually atmosphere——is, at first, proposed. Then, according to the principle some of the questions existed in the designing numerical forecasting models at present are discussed.

• STUDY OF THE INTERNAL BOUNDARY LAYER
• Zhou Dingwen
• 1989 Vol. 8 (4): 370-377. 
• Abstract ( ) PDF (592KB) ( )
• In this paper, the process about the formation of the internal boundary layer (IBL) over a step change of surface roughness is introduced. The importance of IBL researches is set forth and the achievements in theoretical studies, experiments and field observations, as well as numerical simulations on IBL are summarized and analysed.

• A MICROCOMPUTER SYSTEM FOR REAL-TIME OBJECTIVE ANALYSIS AND DIAGNOSIS
• Lu Shihua;Zhou Mingchun;Zou Yaoren;Wu Shijie
• 1989 Vol. 8 (4): 378-380. 
• Abstract ( ) PDF (552KB) ( )