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• A METHOD FOR DETERMING SURFACE ALBEDO OVER THE TIBETAN PLATEAU FROM AVHRR DATA
• Zhong Qiang;Wn Shijie
• 1985 Vol. 4 (3): 193-203. 
• Abstract ( ) PDF (778KB) ( )
• This paper presents a method for determing the surface albedo from narrow-band(NB), narrow-field of view(NFOV) measurements of AV-HRR(advanced very high resolution radiometer). The first step of this method is calculating the total planetary albedo from filtered albedos of visible channel and near-infrared channel based on the multiple regression equations. The second step is identifing the cloudfree area with a simple threshold method and deriving the surface albedo from planetary albedo. A two-stream radiative transfer model was used to investigate the effect of the intermediate atmosphere on. the planetary albedo for different seasons over the Tibetan Plateau's area. The solar zenith angle-and surface elevation-depandent parameters characterizing the atmospheric tr-ansmittance and backward scattering cofficients were derived. Based on the analysis of two measurement cases during the summers of 1983 and 1984, the results show that:1) The surface albedo over the Tibetan Plateau area undergoes strong spatial variation. 2) There is an overestimation of the surface albedo over most part of the Tibetan Plateau area in some previous related literatures and climatic atlases.

• A DIAGNOSTIC ANALYTICAL WAY FOR FLOW FIELDS IN THE TIBETAN PLATEAU
• Wang Qianqian;Qian Yongfu;Deng Liping
• 1985 Vol. 4 (3): 204-213. 
• Abstract ( ) PDF (735KB) ( )
• The Winter mean circulation in East Asia is investigated by using a seven-layer primitive equation diagnostic model with a horizontal grid size of 2.5°×2.5°.The calculated results show that the calculated diagnostic wind fields are more similar to climatology than the geostrophic wind fields, especially, in the jet stream area. The effects of the Plateau on flows can be classified into three cases:1.The layer under 850mb is a fric-tional layer; 2.The layer from 700mb to 300mb is a flow-around layer. In this layer the winds tend to flow around rather than to cross over the Plateau, above 400mb the components of the crossing over apparently increase; 3.At 125mb the barrier effect of the Plateau on flow decreases. The calculated vertical motion is found to be consistent with precipitation. A local direct Hadley cell is Present in the Plateau area.

• CONCENTRATION DISTRIBUTION OF ATMOSPHERIC POLLUTANTS UNDER CHEMICAL CONVERSION ACTION
• Shi Jiekuan
• 1985 Vol. 4 (3): 214-220. 
• Abstract ( ) PDF (438KB) ( )
• In this paper, for both the steady and the unsteady stratifications, a set of analytical solutions of secondary Pollutant is obtained under the joint effects of transport, diffusion and chemical conversion and decay in the atmospheric boundary layer.The concentration distribution of the primary pollutant is improved, too. As a result of chemical conversion and decay,the primary pollutant decreases with the downwind distance more rapidly,especially as the mesoscale distance further than 10 km.Appropriately,a higher concentration of the secondary pollutant is stably held for a longer downwind distance.

• ENTROPIC ENERGY FUNCTION AND THE MEAN GLOBAL CLIMATE——A MEAN ZONAL THERMODYNAMIC MODEL CONSTRAINED BY THE MINIMUM ENTROPY EXCHANGE PRINCIPLE
• Li Tianshi
• 1985 Vol. 4 (3): 221-229. 
• Abstract ( ) PDF (1241KB) ( )
• On the basis of Paltridge's 'minimum entropy exchange' principle, a new concept-entropic energy function-is presented in this paper. Most of the parameters used in Paltridge's model are induced, but some of them are revised in order to make their physical meanings much clearer. With a constraint of minimizing the 'entropic energy function', we have obtained a zonal average distribution of surface temperature T, cloudness θ and meridional flux of energy, which is coincided with the observations. Sen-sitivity experiment shows that if the content of CO ₂ in the atmosphere is doubled,the surface temperature would be 0.8°K higher.It is in agreement with some of the energy balance models.

• THE RELATIONSHIP BETWEEN TOPOGRAPHY AND PRECIPITATION IN YA'AN DISTRICT
• Peng Guikang;Li Zhiyou;Chai Fuxin
• 1985 Vol. 4 (3): 230-240. 
• Abstract ( ) PDF (2213KB) ( )
• In this paper, the relationship between toporraphy and precipitation in the West Sichuan is studied.The main results are as follws:(1) The influences of Ya'an's topographies combined by windward-side, glen, trumpet, valley and mountain on the precipitation are distinct.(2) The main causes of the heavy rain in Ya'an are the moist air canverging and upward sloping forced by topographies and orographic vortex.(3) The rates of orographic rain to the rainfall amount in a year, in the winter and spring and in the summer and autumn are 30%,29%, 39% respectively, among which, the heavy rain rate is alout 50%.(4) The mean height of maximum precipitation in a year is about 1500 meters, being near the mountain in Northern Ya'an district.

• THE ENERGY TRANSPORT AND TELECONNECTION EFFECT IN A GLOBAL BAROTROPIC ATMOSPHERE
• Yan Hong;Liu Mei
• 1985 Vol. 4 (3): 241-251. 
• Abstract ( ) PDF (713KB) ( )
• The wave propagation and energy transport caused by topography and forcing sources in barotropic atmosphere are investigated based on the numerical simulation using a global shallow water equation model with energy and potential enstrophy conservations and harmonic analysis.The possible teleconnections between the forcing sources and the adjustments of global circulation in summer and winter season are addressed. The results show that the displacement of forcing sources might be one of the most important reasons to cause the east-west oscillation of Tibetan High,and furthermore, this type of oscillation of Tibetan High might be connected with the global adjustment of circulations by the forcing sources.The facts shown in this paper may be helpful for further understanding the wave propagation and energy transport on global scales.

• THE PRELIMINARY ANALYSIS OF THE EFFECT OF THE LAND-SEA DISTRIBUTION AND VAST PLATEAU ON THE MEAN WESTERN AND EASTERN WIND IN SUMMER AND WINTER AND THEIR CHANGES
• Luo Siwei;Lu Shihua;Pan Jingdong
• 1985 Vol. 4 (3): 252-261. 
• Abstract ( ) PDF (710KB) ( )
• In this paper, by using the monthly mean grid-point data for ten years of U.S.A.GFDL, we analyse the distribution and evolution of eastern and western wind belts in 13 cross sections along longitude over the world and compare them with the climatic atlas and some numerical simulations. The results point out that the effect of the land-sea distribution and the vast Plateau on them is very distinct.

• SOME CLIMATICAL FEATURES OF HAILFALL IN WEST CHINA
• Chen Qian
• 1985 Vol. 4 (3): 262-273. 
• Abstract ( ) PDF (832KB) ( )
• In this paper the most recent data for 30 years from meteorological stations at the west of 110°E are used to analyse the regular pattern of time-space distribution of hailfall in the western part of China. At the same time a vast amount of data concerning hailfall in the eastern part of our north-west district are also collected in order to discuss the detailed distribution of hailfall through more densely scattered stations and also the relationship between the duration of hailfall, the size of hailstone etc.with the local topography.