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• A STUDY OF THE MASS FLUX TERM NEAR THE POLE IN THE ARAKAWA-LAMB POTENTIAL ENSTROPHY CONSERVING SCHEME
• Yan Hong
• 1984 Vol. 3 (1): 1-12. 
• Abstract ( ) PDF (738KB) ( )
• On application of the Arakawa-Lamb Potential Enstrophy Conserving (PEC) scheme to global numerical modeling with steep topography it was found that it might be possible to make a little improvement on the original scheme for the mass flux term In the near-pole area.A 48 day comparison test was performed to show the differences between the original and modified schemes.

• THE EFFECTS OF THE QINGHAI-XIZANG PLATEAU ON THE MEAN GENERAL CIRCULATION IN EAST ASIA IN SUMMER
• Wang Qianqian;Wang Anyu;Li Xuefeng;Li Shuren
• 1984 Vol. 3 (1): 13-26. 
• Abstract ( ) PDF (1029KB) ( )
• In order to investigate the effects of large-scale topography and heating sources and sinks induced by it on the mean general circulation in East Asia in summer, we use a 5-layer primitive equation numerical model developed originally by Kuo and Qian to make four kinds of experiments. The topography used in the model is close to the real one. The heating sources and sinks of the model are the stationary ones' computed by Yiao et al. with the actual data of July, 1979. The initial geopotential heights used in this investigation are taken from mean July zonal average. We have done 4 experiments of simulation.The first one (designated by HN) has no diabatic heating but orography included and the second (by HH) has both diabatic and orographic factors included. Because in summer the two most important heat sources are located at the Qinghai-Xizang Plateau and Bangladesh region, respectively,in East Asia, therefore based on the HH experiment we designed the third and the fourth experiments. The third (by PN) has no heating in Plateau, while the fourth(by MN) has no heating in Bangladesh region. In this paper a detailed comparison of the four experiments with one another is given.

• A DYNAMIC STUDY OF THE MECHANISM ON THE CIRCUIATION ADJUSTMENT
• Wang Xingrong
• 1984 Vol. 3 (1): 27-35. 
• Abstract ( ) PDF (671KB) ( )
• In this paper, from basic equations, the equation of stratification parameter and the equation of potential vorticity are obtained and discussed. By analysing the potential vorticity process from nonconservation to conservation, which is called the adjustment process of the dynamic excitation by us, the mechanism and the condition on the circulation adjustment are studied.

• THE CLIMATOLOGICALLY SYNOPTIC CHARACTERISTICS OF THE SHEAR LINE ON THE 500mb SURFACE OVER THE QINGHAI-XIZANG PLATEAU
• Xu Guochang
• 1984 Vol. 3 (1): 36-41. 
• Abstract ( ) PDF (374KB) ( )
• Using the monthly mean upper data (1960-69) ,we calculated and analysed the thermal and dynamic characteristics of the shear line on the 500mb surface over the Plateau which is found to exist generally to the north of high temperature center and at the belt of the relative less temperature range between ground and air. The shear line generally is the northern boundary of monsoon circulation over the East Asia. It is not only a simple thermal low. We preliminarily consider that the formation of the shear line may be mainly due to the dynamic effect of orographically induced rounding flow, when the westerly increases to the north of the Plateau and decreases over the Plateau by the heating effect of the plateau ground in summer.

• THE RELATION BETWEEN THE ACTIVITY OF 100mb SOUTH ASIAN HIGH AND THE HEAVY RAIN
• Zhang Hongcai
• 1984 Vol. 3 (1): 42-49. 
• Abstract ( ) PDF (602KB) ( )
• This paper gives an analysis on the relationship between the activity of 100 mb S.A.H.on July 23-26, 1979 and the development of precipitation over China.It is found, (1)the main precipitation area is located nearby the centre and the ridge line of S.A.H., and shows a tendency of increasing its intensity as the S.A.H.is moving northward. (2) Light and moderate rain areas are almost coincident with the ascending stream areas on 300 mb isobaric surface, but the heavy rain area shows less coincidence. However, there often exhibits a significant divergence gradient zone on 100 mb level over the heavy rain area, it indicates that a prominent nongeos-trophic effect would be produced in upper troposphere and helps the small-and meso-scale systems to develop in the lower troposphere.This may be the very cause for the heavy rain to be produced over there. A general examination of this characteristics is made by the use of historical weather map in 1979, it is found that an area of prominent divergence is shown in the stream pattern near the centre or the ridge line of S.A.H.on 100 mb isobaric surface, and a heavy rain would be expected to occur in that day or the next day. Hence, this qualitative characteristics may be used as an index to forecast the location of heavy rain during a short term.

• A STUDY OF THE BEGINNING AND ENDING OF RAINY SEASON OVER QINGZANG PLATEAU
• Zhang Ningdan;Yao Hui
• 1984 Vol. 3 (1): 50-59. 
• Abstract ( ) PDF (759KB) ( )
• By utilizing the 1951-1970's precipitation data fro.m the nine provinces of Xizang (Tibet), Qinghai, Ningxia, Gansu, Shanxi, Sichuan, Yunnan, Guizhou and Guangxi, we have discussed in this paper on the determinating method of rainy seasons in plateau and its adjacent regions, the characteristics of the beginning and ending of rainy season as well as its duration, and the relations between the plateau rainy season with the circulation, plateau monsoon, burst of southwest monsoon and , the start of mei-yu in the Yangtze River basin.With these studies, some bases for long-range forecast can be provided.

• A STUDY ON THE NET LONG-WAVE RADIATION OVER THE QING ZANG PLATEAU IN SUMMER BY USE OF SATELLITE CLOUD PICTURES
• Zhou Yunhua
• 1984 Vol. 3 (1): 60-72. 
• Abstract ( ) PDF (875KB) ( )
• Net long-wave radiation was measured by the Eppley precision infrared radiometers at six stations in the period of the Qinghai-Xizang Plateau Meteorological Experiment(QXPMEX)during May to August,1979.Based on observational data measured ten times a day,the monthly and the ten-day mean net long-wave radiation were obtained.The correlatioins between the mean net long-wave radiation and the cloud coverage were analysed.It is shown that the net long-wave radiation over the Qing Zang Plateau in summer can been evaluated by the empirical formulae containing one variable only.This variable is the cloudiness or percentage of sunshine.
  Because the weather stations are sparse on the Qing Zang Plateau,an attempt was made to derive net long-wave radiation from cloudiness obtained from the satellite cloud picture.Using the TIROS-Ninfrared televisioin pictures over the Qing Zane Plateau twice a day in the period of May-August 1979,the values of the cloud cover by 2°×2°grids were estimated and then the monthly and ten-day mean cloudiness distributions during this period were made.It is found that there exists a good relationship between the mean net long-wave radiation F and the mean cloudiness n1 from the satellite cloud picture.This relation can be expressed as F=a ₁-b ₁n ₁ ^1-7,where the empirical coefficients a1 and b1 are constants over the whole Qing Zang Plateau,not depended on the variation of regions.The correlation coefficients are -0.96 and -0.90 for monthly and for ten-day mean net long-wave radiation,respectively.By means of the empirical formulae,the monthly and the ten-day mean net long-wave radiation are calculated by using the clouditiess observed from the satellite on 2°×2°grid and then every month and every ten-day mean long-wave radiation distribution charts over the Platean during May to August,1979,have been prepared.

• A DISCUSSION ON THE COMPUTATION METHOD FOR THE CLIMATE FROM THE TOTAL QUANTITY OF EFFECTIVE RADIATION AT ARBITRARY PERIODS ON QINGZANG PLATEAU
• Weng Buming;Chen Wanlong;Shen Jiaocheng;Gao Jiabiao;Ji Guoliang;Shui Dengchao;Yang Huayi
• 1984 Vol. 3 (1): 73-82. 
• Abstract ( ) PDF (638KB) ( )
• On the basis of the analysis to the merits and demerits of common empirical formulae, this paper presents a discussion result for the computation method of effective radiation.According to a simple physical consideration, we advance here some new empirical formulas for computing the total quantity of the effective radiation of Qingzang Plateau at arbitrary periods through the comparison of some other computing schemes.Our proposed formulas have the merits in definite meaning, simple computation and higher precision.It is most suitable for popularizing their use for the work on plateau.By the use. of the newly presented formulae,computation and sample diagrams are readily made for the effectrve radiation in daily total as well as in totals of three days, pentad, decade and a month.