Current Issue

• THE RHYTHM OF DESTRUCTIVE EARTHQUAKES AROUND THE NORTHWEST PACIFIC,EI Nino AND EARTH ROTATION
• Tang Maocang;Zhang Jian;Yang Liang
• 1993 Vol. 12 (3): 235-242. 
• Abstract ( ) PDF (561KB) ( )
• By analysing the NW Pacific destructive earthquake(Ms7) data for recent 100 years,it is found that the seismic activity may be divided into two phases:"active period" and "quiet period" alternatively.The correlation coefficient between the "active period" and the "E1 Nino event" is 0.62,which means the degree of confidence is much higher than 0.001.There are also a good synchronization between the "active period" and the deceleration of earth rotation.Finally,the possible cause of the synchronization among the "active period",E1 Nino event and the deceleration of earth rotation is simply discussed,which suggested that a positive disturbance overlapped on the Pacific mantle convection cell may be the possible cause.

• A STUDY OF CLIMATIC CHANGES IN GANSU PROVINCE DURING THE LAST 5000 YEARS
• Dong Anxiang
• 1993 Vol. 12 (3): 243-250. 
• Abstract ( ) PDF (627KB) ( )
• By using the historical records,geological data and the tree-ring chronology,we have drawn the temperature variation curve during the last 5000 years.It is concluded that four warm periods included 3000 B.C.-1000 B.C.,770 B.C-44 B.C.,582 A.D-960 A.D.and 1192 A.D.-1427 A.D.,the four cold periods included 1000 B.C.-770 B.C.,43 B.C-581 A.D.,961 A.D-1191 A.D.and 1428A.D-1870A.D..

• THE CONTRAST ANALYSIS OF KINETIC ENERGY BUDGET FOR DEVELOPING TROUGH AND SHEAR LINE OVER THE QINGHAI-XIZANG PLATEAU
• Yu Shuhua;Luo Hong
• 1993 Vol. 12 (3): 251-256. 
• Abstract ( ) PDF (399KB) ( )
• The kinetic energy budget for a developing trough and a shear line over the Qinghai-Xizang Plateau,which occurred respectively in the period from 25 to 28 July 1982 and from 4 to 6 June 1982,had been studied by the diagnostic analysis.The same features are:(1) there is a process of transformation from effective potential energy into kinetic energy,and the maximum value of kinitic energy transformed appears when the trough is developing and extending southwards and the shear line is stabilizing.(2) The kinetic energy is decreased by divergence of the flux of potential energy is most obvious when the trough is developing and the shear line is stabilizing.The different features are:(1) the value of kinetic energy in shear zone is larger than that in trough zone.(2) The kinetic energy is increased by the term of energy source when the shear line forming,and the kinetic energy is decreased by the term of energy source when the trough developing.

• THE CHARACTERISTICS OF GROUND FLASHES DETECTED BY M-LDARS IN BEIJING REGION
• Li Xi;Tao Shanchang
• 1993 Vol. 12 (3): 257-263. 
• Abstract ( ) PDF (445KB) ( )
• In the summer of 1991,we performed a lightning location experiment in Beijing by using the Monostatic Lightning Detecting and Ranging System(M-LDARS),with dipole antenna,which manufactured by ourselves.By analysing the record of return strokes,we have obtained the typical characteristics of the strokes,some parameters about the electric field radiation and its spectra.This result is reasonably comparable with other published work.

• THE STUDY OF HEAT BALANCE AND MOISTURE BUDGET OVER THE SOUTH AND CENTRAL PART OF HENGDUAN MOUNTAINS IN CHINA DURING THE SUMMER OF 1985
• Ma Yimin;Song Zhengshan;Gao Dengyi
• 1993 Vol. 12 (3): 264-273. 
• Abstract ( ) PDF (635KB) ( )
• The Hengduan mountains are located in the southeastern part of the Qinghai-Xizang Plateau.In this paper,we analysed the three dimensional dynamic and thermal structures of atmosphere and calculated the heat and moisture budget and transfer over the Hengduan mountains using the conventional meteorological data obtained in a special observation period from 5 June to 4 August,1985.The computational domain is a area occupied by six stations,among them the three stations were new setted.Our results show that the south-westerly flow connected with the Indian SW summer monsoon brings moisture into this region and produces rainfall.There is a moisture channel over this region to transfer water vapor from south-west to the inner China.There exist strong dynamical cyclonic relative vorticity in the lower layer and anticyclonic vorticity in upper troposphere.The upward motion dominates throughout the whole troposphere due to the forcing effect of the topography and the local dynamical convergence in low levels.It has been explored that there are obvious heat source and moisture sink showing importance of the latent heat released by condensation process over the Hengduan mountains which is consistent with the characters of the atmospheric structure.The formation of the heat source is favorable to the maintenance of the anticyclone in the upper layer.A climatic high frequency appearance center of the upper anticyclone has just been found in or near the area of Hengduan mountains.

• ANALYSES AND DIAGNOSES OF THE DEVELOP-MENT OF A WINTER MEDITERRANEAN CYCLONE
• Peng Xindong;Chou Jifan;Cheng Linsheng
• 1993 Vol. 12 (3): 274-282. 
• Abstract ( ) PDF (634KB) ( )
• Analysis and diagnosis results of a intensely developed Mediterranean cyclone(MC) of 7-10 January 1981 were given in this paper.They showed that the stable winter meridianal flow following the circulation trough in this area,the Alps mountain and the Mediterranean Sea play important effects in the processes of cyclone generation and development.The key of cyclone generation is the cooperation of the Alps and the meridianal flow which perpendicular to the Alps.The Mediterranean acts as a heat source in winter and provides an advantage condition to the MC evolution.

• THE NUMERICAL EXPERIMENTS OF OROGRAPHIC INFLUENCE ON TWO COLD-OUTBURSTS
• Hui Xiaoying;Luo Siwei
• 1993 Vol. 12 (3): 283-293. 
• Abstract ( ) PDF (783KB) ( )
• In this paper we have investigated two cold-outbursts through numerical simulations with FGGEⅢb data and the model of primitive equation over the complex topography.It shows that the mountain dynamic effect plays important role in four weather-systems over the East-Asia:(1) forming and developing of the Mongolian High;(2) forming of topographic trough over north-east side of the Qinghai-Xizang Plateau;(3) forming and developing of the Lanzhou High;(4) the moving southward path of the cold air.

• THE STUDY ON THE VARIATION OF THE SURFACE ALBEDO OVER THE QINGHAI-XIZANG PLATEAU
• Shen Zhibao;Zuo Hongchao
• 1993 Vol. 12 (3): 294-301. 
• Abstract ( ) PDF (576KB) ( )
• Based on the physical cases of the surface albedo variation it could be divided into 3 types,i.e.self-,random variations and the variation with the sun's altitude.By the analysis of the observational data from 4 stations over the Qinghai-Xizang Plateau,a formula for representing the relationship between the surface albedo and sun's altitude,and some useful results about the self-variation have been obtained.

• STUDY OF THE CORRELATION BETWEEN SOLAR ACTIVITY,OZONE AND TEMPERATURE IN THE STRATOSPHERE
• Yan Muhong;An Xuemin;Zhang Yijun;Hua Guiyi
• 1993 Vol. 12 (3): 302-311. 
• Abstract ( ) PDF (737KB) ( )
• The correlations between the 10.7 cm solar radio flux,the solar flare burst and the temperature in the lower stratosphere,the column ozone in the atmosphere has been analysed,respectively,in this paper.The results show that there are certain correlations between them on two time scales:11 years and a few days.The correlations usually occur in the higher latitude,and are very obvious for the west phase of the quasi-biennial-oscillation(QBO) and in the winter.The correlations between the solar activity and the temperature in the lower stratosphere,or the column ozone are synchronization for two time scales.The possible physical mechanism above mentioned correlations are also discussed in the paper.The results indicate that the solar ultraviolet radiation and high-energy corpuscular stream are main carriers of solar variability to influence on the lower atmosphere.It is a possible mechanism that the variation of temperature in the stratosphere is modulated by the variation of the column ozone.

• NUMERICAL SIMULATIONS OF DYNAMICAL IMPACT OF QINGHAI-XIZANG PLATEAU ON LOWER-LEVEL JET ON ITS EAST SIDE IN SUMMER
• Chen Yuchun;Qian Zhengan
• 1993 Vol. 12 (3): 312-321. 
• Abstract ( ) PDF (735KB) ( )
• In order to study the dynamical impact of Qinghai-Xizang Plateau(QXP) topography on the lower-level jet(LLJ) on its east side,in this paper a series of six experiments have been designed and simulated and forcasted for both '81.7' and '79.7' LLJ cases chosen for 48-h,utilizing a limited-area model favoured for the complex terrain region and the FGGE Ⅲ b-level and ECMWF's gridded data.The experiments designed are the ones having quite real QXP elevation,half and removing the QXP terrain,removing the southeast corner of the QXP orography only,and pure flowing around and crossing over the QXP airflow respectively.The results show:(1) The model can forecast the LLJ and precipitation quite well;(2) Under the favourable condition of circulation pattern of westward extending and northward advancing of Subtropical High over West Pacific(SHWP) in Summer,when the stronger southeast flow on the southwest flank of the SHWP meets the east boundary obstacle of the QXP,the flow will flow around its east edge and change into southerly wind,the wind tunneling effect makes the flow speed further up,so the southerly LLJ on the east side of the QXP forms.Namely the QXP has the important influence on the LLJ,but the influence of the QXP terrain on the southeasterly or southwesterly LLJ over South China and mid-and lower-reaches of Yangtze River is not obvious;(3) There is quite closed relationship between the precipitation on the northeast side of the QXP and the southerly LLJ on the east side of the QXP.

• A PRELIMINARY ANALYSIS OF RELATIONSHIP BETWEEN TORRENTIAL RAIN AND UNDERLYING HEAT FIELD IN MID-AND LOWER-REACHES OF YANGTZE RIVER
• Fan Xingang
• 1993 Vol. 12 (3): 322-327. 
• Abstract ( ) PDF (402KB) ( )
• The relationship between torrential rain and underlying heat field was studied by using the soil temperature data of shallow layer of meteorological stations.It shows that there is a forerunner of torrential rain on the underlying heat field,that is the upward geothermal heat flux from deep layer to earth surface.The torrential rain locates near the positive heat flux area,in the mean while,it's also influenced by the synoptic background.

• ANALYSIS AND PREDICTION ON THE COLD AND WARM CIRCULATION FEATURES IN EARLY SPRING IN CHINA
• Yang Shangong;Guo Jun
• 1993 Vol. 12 (3): 328-332. 
• Abstract ( ) PDF (338KB) ( )
• The cold and warm circulation features in early spring in China are anaiysed.The cold and warm circulation features in early spring over larger areas in China are concluded.It is found that the cold and warm circulation features are relative with some anomaly of general circulation during earlier stage in Northern Hemisphere.Prediction equation on the cold and warm circulation features in early spring in China is builded up by selecting earlier stage general circulation features having a close relation.There is an obvious correlation between the theoretic values and values observed at representative stations in Chian.These provide a new clue for prediction of early spring temperature at weather stations in China.

• PRELIMINARY RESEARCH FOR METHOD OF HAIL DETECTION WITH C BAND DUAL LINEAR POLARIZATION RADAR
• Liu Liping;Zhang Hongfa;Wang Zhijun;Song Xinming
• 1993 Vol. 12 (3): 333-337. 
• Abstract ( ) PDF (356KB) ( )
• The hail signal H _DR for dual linear polarization radar has been introduced depending on the rain drop size distributions data and scattering functions for rain drops.Based on the radar data and hail reports on the ground,we have analysed the Z _DR distribution rule in the CAPPI radar data,and the relations between H _DR and the hail informations on the ground.The preliminary results have showed that hail detection with H _DR is satisfactory.This work is applied valuable to cloud physics study and hail modification.

• THE SOFTWARE DESIGN OF SYNTHETICAL ANALYSIS ON LIGHTNING DATA AND RADAR ECHO DATA
• Meng Qing
• 1993 Vol. 12 (3): 338-346. 
• Abstract ( ) PDF (524KB) ( )
• The software is designed for the synthetical analysis works in large amounts of lightning data and radar echo data obtained from the field expriments.It is provided for six functions which include the analysis of statistic characteristics of lightning data,lightning data distribution overlay radar echo data,etc..The software is improved in the accuracy,reliability and speed for the analysis work,and makes the statistic analysis in large amounts of data possible.This paper illustrates the principle and method of design,and functions are provided.