Current Issue

• THE INFLUENCE OF ATMOSPHERIC DUST ON THE SURFACE RADIATIVE ENERGY BUDGET IN THE HEIFE AREA
• SHEN Zhi-Bao;WEI Li
• 1999 Vol. 18 (1): 1-8. 
• Abstract ( ) PDF (307KB) ( )
• The influences of the atmospheric dust on the surface radiative energy budget was analysed and estimated by using the data of the atmospheric turbidity and the surface radiation balance observed at Zhangye (oasis) and Desert stations in the HEIFE area during the period from the third decade of February to the secend decade of May in 1991.The downward components of both short and long wave radiations are affected obviously by the atmospheric dust. There are a good relationship between the atmospheric transmitttance and atmospheric turbidity coefficient. The atmospheric transmittance and surface global radiation decrease as the atmospheric turbidity increase. The surface global radiation at noon decrease 67.6~85.8 W/m ²(7.0%~9.2 %) in April when the atmospheric turbidity increase from 0.1~0.6, in other words, it decrease 1.3%~1.9% as the atmospheric turbidity increase 0.1. This decrease is larger in the desert than that in the oasis. The positive corelation was fund between the downward long wave radiation and the atmospheric turbidity. The downward long wave radiation at noon increase more than 21.6 W/m ² (9.0%~10.5%)at Desert station and 17.3 W/m ² (7.6%~12.8%) at Zhangye station respectively in the very turbid days (the atmospheric turbidity coefficient are larger than 0.450) as compared with that in the clear day. The same results were fund in the night. The upward long wave radiation seems to decrease in the turbid day. The influence of the atmospheric dust on the surface radiative energy budget is to decrease the surface net radiation in the day time, but not obvious in the night. The surface net radiation at noon decreases about 43~58 W/m ² (about 9%~12%) in the very turbid days at Desert station as compared with that in the clear day, but at Zhangye station the results are not the regurarity same as that at Desert station because the surface conditions in the oasss were affected by the irrigation.

• CONVECTIVE ACTIVITIES OVER THE QINGHAI-XIZANG PLATEAU AND ADJACENT REGIONS IN SUMMER OF 1995
• ZHU Guo-Fu;CHEN Shou-Jun
• 1999 Vol. 18 (1): 9-19. 
• Abstract ( ) PDF (390KB) ( )
• A statistical research based on hourly infrared cloud top black body tempera-ture (TBB) data from GMS during summer 1995 is conducted to show the synoptic climatol-ogy of convective activities over the Plateau and its adjacent regions. Some results are ob-tained as follows: There are three discrete major areas where convective activties frequently occur; they are, in the order of precedence, Bay of Bengal to India, the Qinghai-Xizang Plateau, and Laos to Leizhou Peninsula. The most frequent convective region over the Plateau is centered at 30°N, 90°E, not in the eastern Plateau. There are few convective ac-tivities at the delta exit of the Yarlung Zangbo River. The convective activities over the Plateau have a pronounced diurnal cycle and the strengtheming process in the cycle is more rapid than the weakening process. In addition, both inter-monthly variations and diurnal cycle of convective activities over Bay of Bengal to India and the Qinghai-Xizang Plateau are different.

• THE INFLUENCE OF INITIAL AND BOUNDARY CONDITIONS ON THE SIMULATED RESULTS OF REGIONAL CLIMATES OVER QINGHAI XIZANG PLATEAU
• LIU Li-Ping;QIAN Yong-Fu;WU Ai-Ming
• 1999 Vol. 18 (1): 20-27. 
• Abstract ( ) PDF (350KB) ( )
• We simulate the regional climate in the Qinghai-Xizang Plateau,utilizing the regional model (MM4) and one-way nested technique, compare the simulated results with different nesting methods and discuss the effects of initial and boundary conditions on the simulated results. The results show that main regional climate features are reproduced by the regional climate model but the simulated results nested with GFDL data are better than that with GCM simulated values, the errors simulated by the GCM could certainly affect the sim-ulated results of the nested model MM4.

• SIMULATION OF REGIONAL CLIMATE OVER EASTERN CHINA WITH DIFFERENT REGIONAL CLIMATE MODELS
• WANG Shi-Yu;ZHANG Yao-Cun
• 1999 Vol. 18 (1): 28-38. 
• Abstract ( ) PDF (416KB) ( )
• Three regional climate models (MM4,RegCM2 and P- σ incorporated coordi-nate model)have been used to simulate the regional climate over eastern China in July.It is found that these three models have different performances in simulating different climate ele-ments such as 500 hPa geopotential high field,temperature fields,sea level pressure and rainy belt location.The results are important for developing regional climate model system which is suitable for eastern China and improving the simulation and forecast results.

• WAVELET TRANSFORMS' APPLICATIONS TO RESEARCHES ON MODEL OF SHORT RANGE CLIMATE FORECAST
• YOU Wei-Hong;QI Ming-Hui;DUAN Xu
• 1999 Vol. 18 (1): 39-46. 
• Abstract ( ) PDF (291KB) ( )
• By using the wavelet coefficients of wavelet transform and their inverse trans-forms, a climate forecast model of multi-time scale has been established. The forecast experiments of monthly surface air temperature anomlies for Kunming, Yuxi, Chuxiong and monthly precipitation anomlies for Central Yunnan in 1991~1996 are run at month, season and year forecast time scales. By verifying the experimental forecasts, the conclusions are that the climate forecast model established by this paper is very significant in forecasting anomaly values of monthly surface air temperature anomlies at month, season and year time scales, and the forecast accuracy of anomaly sign of the model can reach 73.1%, 73.1% and 69.4% at the 3 time scales respectively. The forecast effects of monthly precipitation are less significant than air temperature and they are significant only at month and season time scales in rainy season (May~October), but they are little effective in drought season (November~April) and at year time scale.

• CONTINUOUS WAVELET TRANSFORMS AND THEIR APPLICATIONS TO SURFACE AIR TEMPERATURE AND YEARLY PRECIPITATION VARIATIONS IN YUNNAN DURING LAST ONE HUNDRED YEARS
• YOU Wei-Hong;DUAN Xu;QI Ming-Hui
• 1999 Vol. 18 (1): 47-54. 
• Abstract ( ) PDF (354KB) ( )
• Using Marr wavelet and Morlet wavelet transforms, the variations of surface air temperature and yearly precipitation in Yunnan Province during the last hundred years are analysed. Some multi-time-scale and jump features of the variations have been discovered. These features are very important in short-range clim ate forecast for Yunnan Province. They give the multi-time-scale pattern and the background of Yunnan climate changes.

• DIAGNOSIS ANALYSIS OF SERIOUS DROUGHT EVENT OF 1997 IN GANSU
• BAI Hu-Zhi;XIE Jin-Nan;WANG Bao-Lin;LIU De-Xiang;ZHAO Hong-Yan
• 1999 Vol. 18 (1): 55-62. 
• Abstract ( ) PDF (404KB) ( )
• The serious drought event of 1997 in Gansu is analyzed. The result shows that effect of high SST in equator east Pacific and of the blocking situation in the Baikal Lake and of cold winter in SW Qinghai-Xizang Plateau lead to drought occuring in Gansu. Mean-while, it is one important reason which subtropical high pressure over the west Pacific is slightly weaker than normal.

• A STUDY ON RELATION BETWEEN THE PRECEDING CIRCULATION AND THE RAINFALL IN YUNNAN DURING EARLY SUMMER
• JU Jian-Hua;LI Xun-Li
• 1999 Vol. 18 (1): 63-70. 
• Abstract ( ) PDF (362KB) ( )
• The influences of the abnormal circulation in preceding winter and spring on the rainfall in Yunnan during early summer have been analyzed. The characteristics of west-erly circulation in mid-high latitude areas and zonal wind fields in subtropical areas have been analyzed for drought and flood years respectively by using a composite method. The results show that the amount of rainfall in Yunnan during early summer were influ-enced by abnormal characteristics of geopotential height fields on 500 hPa level over mid-high latitude areas and subtropical zonal winds on 200 hPa level in preceding winter and spring.

• SOME CLIMATIC FEATURES OF THE FIRST HEAVY RAINFALL OVER THE EASTERN SANXIA REGION IN SPRING
• YE Qian;XIE An;LIU Xia
• 1999 Vol. 18 (1): 71-78. 
• Abstract ( ) PDF (452KB) ( )
• Climatic characteristics of the first heavy rainfall over the eastern Sanxia re-gion in spring have been analyzed by using sixteen-year NMC data and OLR observations. It has been found that (1) the first rainfall is mainly caused by the cold air from west; (2) the convection systems over the Qinghai-Xizang Plateau have direct impact on the rainfall;(3) the moisture transport from the Indochina Peninsula through the south-western China provides a necessary condition for the first rainfall.

• STATISTIC CHARACTERISTICS OF THE EARTH SURFACE DEFORMATION FIELD AND ITS CORRELATION WITH THE GROUND TEMPERATURE FIELD
• GUO Wei-Dong;TANG Mao-Cang
• 1999 Vol. 18 (1): 79-87. 
• Abstract ( ) PDF (426KB) ( )
• Interpolating the ground tilt data in mainland (south to 45°N, east to 97°E, totally 41stations)during 1986 to 1990 into grid points of 1°×1°, the monthly earth surface deformation field was calculated. Some characteristics of deformation field can be identified from it including convex area、concave area and saddle area, etc. The results show that there are usually 4~5 convex and concave areas respectively on monthly or seasonal deformation field with an average horizontal scale of 400 km or so and a life span of 3.5 seasons approxi-mately. The concentration region of centers of convex/concave areas consists with the earthquake belts. Moreover, the convex area is well corresponding to the Underground hot vortex "while the concave area is in good agreement with Underground cold vortex", which strongly supports the conceptual model indicating the couple between the earth and the atmo-sphere proposed in Reference 8.

• MEASUREMENTS AND ANALYSES OF THE VARIATION OF THE ATMOSPHERIC ENVIRONMENTAL PROPERTIES IN XIAOZHANGZHUANG ECO VILLAGE AREA
• ZHANG Hong;YAO Ke-Ya;CHEN Yue-Juan;CAO Wen-Bo
• 1999 Vol. 18 (1): 88-96. 
• Abstract ( ) PDF (394KB) ( )
• The concentrations of pollutant gases (including SO ₂,O ₃ and NO _X) and aerosol at the ground surface were measured in Xiaozhangzhuang eco-village area during Oc-tober 1997,May 1995 and April 1997. The results obtained from measurements and analyses display some average characteristics, time-variation and season-variation of pollutant gases. It shows that the atmospheric environment over Xiaozhangzhuang area is clear during the measurements. The results show that the photochemical reaction controlled by overall solar radiation is the determining factors affecting the variation of the surface O ₃. Fine aerosol is over 99% of the total amount. Its daily variation is strongly influenced by convection and turbulent diffusive transfer and its concentration spectrum displays single-peak and single-val-ley. There are obvious correlation between aerosol concentration and air humidity.

• PRECIPITATION ESTIMATE USING DUAL LINEAR POLARIZATION RADAR Ⅰ. ASP METHOD
• CHU Rong-Zhong;JIA Wei
• 1999 Vol. 18 (1): 97-108. 
• Abstract ( ) PDF (491KB) ( )
• Parameter of Z-R relation for precipitation estimate using dual linear polar-ization radar getted though ASP(approximate along sort and pair) method have been repre-sentativenese then linear fit. ASP method can give expression to the objective of raising the precision of estimate area precipitation. It can use other error to measure the parameter in concrete conditions,too. High error of observed intensity of rain is dominant factor that using ASP method to get the parameter. Parameter A ₀, A _H and A _DR of Z-R relation of exponent function is 0.016 84,0.096 and -0.416 5,respectively. The method can be applied to complicated function of many variance and factor.

• PRECIPITATION ESTIMATE USING DUAL LINEAR POLARIZATION RADAR Ⅱ. CLASSIFIED ANALYSIS OF ERROR
• CHU Rong-Zhong;LI Xiao-Ping
• 1999 Vol. 18 (1): 109-117. 
• Abstract ( ) PDF (378KB) ( )
• The Z-R relation for precipitation estimating and all error were researched. The results are as following:There are not obvious difference between exponent and power function for Z-R relation;Parameter A _H about can't too big;Estimate error of rainfall was the smaller in the all error using dual linear polarization radar;Standard error of no fit error for Z-R relation can't be neglected because it was about 0.215;Estimate error of rainfall appeared a normal distribution that deviation near 0 and standard error is about 0.265,the re-sult is very important for raising the precision of estimate area precipitation.

• THE SYNTHETICAL INCREASE PRODUCTION POTENTIALITIES OF THE MAIN CROPS IN GUIZHOU
• GU Xiao-Ping;LIU Xue-Mei;WU Wen-Hui;HUANG Ju-Mei;LI Wei
• 1999 Vol. 18 (1): 118-126. 
• Abstract ( ) PDF (398KB) ( )
• On the basis of the atmosphere-crop-soil systems, the synthetical production potentiality model of the grain crops is established in Guizhou, the concept of crop increase production potentiality index is posed, the prospects of the synthetical increase production potentialities of crop uder the present and future circumstances are analysed.