Current Issue

• PRELIMINARY RESULTS OF MEAN SOIL HEAT FLUX CALCULATED BY SOIL TEMPERATURE DATA OBSERVED AT METEOROLOGICAL STATIONS
• Dong Wenjie;Tang Maocang
• 1992 Vol. 11 (2): 115-125. 
• Abstract ( ) PDF (695KB) ( )
• According to linear heat conduction theory in half limitedless space, the soil temperature data at the depths of 0.8 m and 3.2 m observed at meteorological stations from 1954 to 1989, have been used for calculating soil heat flux. Preliminary results are that:(a) If soil temperature data observed at meteorological stations are more than 11 years, they can be used for calculating the average of soil heat flux(also can be called earth surface layer heat flux) after filter analysis.(b) Both methods given in this paper and in Wang's(Wang, 1990) are the same precise for calculating thermal conductivity.(c) The soil temperature data observed in Beijing station have been analyzed, for example, which demonstrated that there exist good corresponding relationships among the soil temperature gradient, annual precipitation and earthquake.(d) Both the directions and the orders of magnitude of the heat flow at the earth surface layer and that at the deep are the same in the most of calculated area. And in the area where there are two kinds of heat flows mentioned above, their distribution patterns are accordance to each other.(e) The heat flows at the surface layer is contrary to that at the deep in desert, this means that there is a " heat sink layer" at the adequate depth under the desert,(f) There is a great similarity between the locations of high bands of soil heat flux and the earthquake bands in China.

• A RESEARCH ABOUT TURBULENT TRANSPORT AND INTENSITY OVER COMPLEX TERRAIN OF LANZHOU
• Zhang Qiang;Hu Yinqiao
• 1992 Vol. 11 (2): 126-132. 
• Abstract ( ) PDF (446KB) ( )
• In the paper, we calculated and analysed gradient and fluctuation data of wind and temperature measured in the observation experiment of the surface layer in early winter, 1986 in Lanzhou. Characteristics of turbulent transport and intensity in the surface larger over complex terrain are studied. It is found that turbulent transport is far larger over the hilltop than the half way up the mountain and mountain valley in Lanzhou, beside, in unstable air, turbulent intensities of vertical velocity and temperature over half way up the mountain obey Monin-Obukhov similarity theory.

• THE MONTHLY IRRADIATION OF THE POSSIBLE DIRECT RADIATION AT EACH LATITUDE UNDER VARIOUS ATMOSPHERIC TRANSPARENCY OVER THE ARID REGION OF THE WEST CHINA
• Wei Zhigang;Wang Yaoqi
• 1992 Vol. 11 (2): 133-143. 
• Abstract ( ) PDF (553KB) ( )
• In this paper, based on the empirical formula of the irradiance of the solar direct radiation variation with the air mass and the atmospheric transparency over the arid region of the West China, we have computed the monthly, irradiation of the possible direct radiation over the area with 2° interval from 28° N to. 50° N and the coefficients of transparency( P ₂) with 0.05 interval from 0.55 to 0.85.

• THE RELATION BETWEEN THE CLIMATIC CHARACTERISTIC OF FO RMATION OF SOUTH-WEST VORTEX AND THE ADVECTION OF ANGULAR MOMENTUM
• Wang Saixi
• 1992 Vol. 11 (2): 144-151. 
• Abstract ( ) PDF (511KB) ( )
• In this paper, the relation between the advection of angular momentum( m=-ρ V·▽ M- M▽·ρ V) in the equations of angular momentum and formation of South-West Vortex is analysed. The result indicates that the changes of advection of angular momentum to generation of the vortex have advanced or restricted action.

• THE SCHEME OF GRAVITY WAVE DRAG PARAMETERIZATION AND FORECAST TEST
• Jiang Ye;Chen Jiabin
• 1992 Vol. 11 (2): 152-160. 
• Abstract ( ) PDF (512KB) ( )
• In this paper, ECMWF scheme of topographic gravity wave drag parameterization is entered into nine levels spectral model that it was designed by Institute of Atmospheric Physics, Chinese Academy Sciences. Two cases of summer and winter with resolution T21 are computed, some effects of gravity wave drag on the cross sections of zonal mean west wind and temperature, the change of kinetic energy and forecast score are analysed and discussed. The results show that the scheme of gravity wave drag parameterization entering into the spectral model is successful.

• A PRELIMINARY INVESTIGATION OF THE DYNAMIC AND THERMODYNAMIC IMPACT OF THE TOPOGRAPHY ON THE MEDIUM RANGE WEATHER PROCESSES
• Huang Boyin;Wu Wanli;Ji Liren
• 1992 Vol. 11 (2): 161-169. 
• Abstract ( ) PDF (610KB) ( )
• This paper uses a spectral model for medium range weather forecast. It is discussed that the dynamic and thermodynamic impact of the topography acts on the medium range weather processes. In the discussion, two typical cases of the summer mei-yu weather and the winter cold-wave weather in China are used. The tendency correlation coefficient of predicted height field with observed one is tested. The variation of 500 hPa height field and sea-level pressure field is analysed. It is found that the pure dynamic impact of the topography on the winter medium range weather processes is very clear. But for the summer case, this impact is weaker. It is also found that the thermodynamic impact is significant on both the winter and summer cases.

• SEASONAL VARIATION OF GLOBAL ATMOSPHERIC CIRCULATION DURING JANUARY TO JULY IN STRATOSPHERE IN 1979
• Tian Rongxiang;Gao Youxi;Qu Zhang
• 1992 Vol. 11 (2): 170-177. 
• Abstract ( ) PDF (537KB) ( )
• Using FGGEⅢ _b data in 1979, the seasonal variation of global atmospheric circulation in stratosphere and their relationship during January to July has been studied in the paper. The results show that the seasonal variation in the Southern and Northern Hemispheres associates with each other. In stratosphere, while the strong easterly wind appears in the low latitudes over the Northern Hemisphere, it disappears in low latitudes over the Southern Hemisphere; while the polar night jet appears in the Southern Hemisphere, it disappears in the Northern Hemisphere. Whichever seasonal variation over the Southern Hemisphere will be related to the variation over the Northern Hemisphere. If we defined that the earliest and the latest areas of seasonal variation are the starting and the ending area of seasonal variation, respectively. Then starting area of seasonal variation is in high latitudes of both hemispheres, the ending area is in middle latitude of the Northern Hemisphere. In the Northern Hemisphere, the Europe is another starting area, but the western part of the Pacific and the eastern part of the Asia and the Atlantic Ocean are the ending areas.

• THE CONDITIONS OF ARTIFICIALLY TRIGGERED LIGHTNING AND PROBABLE EFFECT ON THE CHARACTERISTICS OF THUNDERSTORM
• Zhang Yijun;Yan Muhong;Wang Caiwei;Liu Xinsheng
• 1992 Vol. 11 (2): 178-185. 
• Abstract ( ) PDF (552KB) ( )
• We analyze preliminarily 40 experiments of artificially triggered lightning in 1989-1991 and explore theoretically the results in this paper. The results indicate when we choose the condition of artificially triggered lightning, we can not only depend on the ground electric field. The variation rate of ground electric field △ E/△ t and the distance of lightning activity center to observation station are also very important parameter. The chance of artificially triggered lightning should be chosen in the later stage of natural lightning restoration process which the time of arrival of the thunder is about less than 10 -15s. Meanwhile, △ E/△ t<50V/m·s and E>4 kV/m. The artificially triggered lightning has influence on the characteristics of thunderstorm. After a artificially triggered lightning, the lightning of thunderstorm and change of electric field caused by lightning decrease within short time, the amount of precipitation increase near the lightning channel.

• DISTRIBUTION OF THE ATMOSPHERIC HEAT SOURCE AND ITS CHARACTERISTICS OF EVOLUTION OVER THE ASIAN MONSOON AREA BEFORE, IN AND AFTER MEIYU SEASON IN 1983
• Zou Li;Qiao Quanming
• 1992 Vol. 11 (2): 186-191. 
• Abstract ( ) PDF (411KB) ( )
• In this paper, by using the ECMWF data in summer of 1983, we calculated and diagnostically analysed the atmospheric heat source over the Asian monsoon area. The results show that there are two heating belts over the Asia in summer. The heating belt corresponding to the tropical monsoon trough gradually moved northward and closed to the continental heating belt with the Meiyu season coming in(or going out). The regular movement to north and the east-west oscillation of the heating belts are identical with the evolution of the East Asian monsoon meridional and zonal circulations. The results also show that the characteristics of the atmospheric heat sources relative to monsoon rain belts over the East China obviously have difference before, in and after Meiyu season.

• THE USE OF MONTHLY MEAN INDICES OF ZONAL WIND AT 100 hPa ON CIRCULATION ANALYSIS AND RAIN FORECASTING
• Wang Caiyun
• 1992 Vol. 11 (2): 192-196. 
• Abstract ( ) PDF (288KB) ( )
• By using monthly mean data of 100 hPa in Northern Hemisphere for years of 1956 -1985, the intensity indices of zonal wind could be defined as different value between southern and northern geopotential height from grid points. It is shown that the intensity indices of zonal wind over Qinghai-Xizang Plateau are closely related to that over Northern America Plateau and also closely related to the rainfall in Southern China. Finally, the rainfall forecasting equation in May in Yunnan Province is set up here.

• THE PARAMETERIZED EXPERIMENTS OF MODELING SURFACE WINDS FOR MOUNTAINOUS AREAS
• Li Guojie;Wang Dongyong
• 1992 Vol. 11 (2): 197-202. 
• Abstract ( ) PDF (408KB) ( )
• In this paper, the reasonable determination of the height( H) of topographic influence layer and the atmospheric nonuniform heating are provided, in order to improve the results of mesoscale numerical weather simulation, based on the experiments of one level numerical diagnostic model. It is noted that the height( H) is a very sensitive parameter in this model. A optimum value of H is got through a comparison of simulated value with observation of Dabie Mountain, for the reference of theoretic research and numerical simulation.

• CHARACTERISTICS OF TEMPERATURE DISTRIBUTION IN SUMMER IN QINGHAIKE KEXILI EMPTY QUARTER
• Zhang Lin
• 1992 Vol. 11 (2): 203-207. 
• Abstract ( ) PDF (334KB) ( )
• In this paper, temperature data in Kekexili area of Qinghai Province are analysed. A lot of variation rules and distribution characteristics are found.

• THE RELATIONSHIP BETWEEN THE ATMOSPHERIC OZONE AND THE TEMPERATURE OVER THE NORTHERN HEMISPHERE
• Wu Tongwen;Zheng Guang;Qu Zhang;Hui Xiaoyin
• 1992 Vol. 11 (2): 208-212. 
• Abstract ( ) PDF (338KB) ( )
• In this paper, Using the observed daily mean data of total ozone and temperatures over the northern hemisphere(21 stations) during the period from July 1 to 31,1979, the relationship between them and the influence of one on another have been analysed. The variation of total ozone lags the variation of the temperature at each level of 50-200hPa, and precedes the variation of temperature at each level of 5-50hPa.

• A REVIEW ON THE PROBLEMS OF CUMULUS PARAMETERIZATION
• Chen Bomin;QianZhengan
• 1992 Vol. 11 (2): 213-222. 
• Abstract ( ) PDF (755KB) ( )
• In this review, firstly, the closure assumptions in cumulus convection parameterization have been presented. Then, four schemes typical of cumulus parameterization were classified and their comparisons were made. Again then, the recent progress and the state of the art in the cumulus parameterization have been obriefly reviewed. Finally, some discussions and remarks on the parameterization were given, ,but with a emphasis on the numerical weather prediction.