Abstract:In the context of NCEP/NCAR daily 500hPa geopotential height from May 1 to August 31 in 1998 and China 160 station precipitation data,investigation is conducted on the impact of 500 hPa planetary scale circulation systems on the dual plum rains over the Yangtze River.Evidence suggests that the increase(decrease)in intensity of Ehuocik blocking high in out of phase with the decrease(increase)in intensity of extra tropical western Pacific high in the western part is mostly responsible for the increase(decrease)of rainfall over the Yangtze River and most part of northeast of China during 1998 summer.

Abstract:In terms of data on staging sowing experiments with two line hybrid rice Liangyou Peijiu in Nanjing and Zhenjiang,five critical stages in which high yield could be achieved were chosen.Using regression analysis,models were established and optimal meteorological condition for each stage was obtained.Furthermore,by dint of meteorological data from Ganyu,Xuzhou,Gaoyou,Nanjing,Changzhou,Liyang and Suzhou of Jiangsu Province separately,yield built climate elements were estimated and compared with optimal ones for four crop rotations respectively and recommendations for high rice yield were presented in view of agrometeorological technique.

Abstract:Using five layer nanjing institute of meteorology land surface process model(NIMLSP)for data on meteorological scientific experiment over the Qinghai Tibet Plateau from May to August in 1979, characteristics of land surface process and energy transport were both simulated for different regions over the plateau for summer season. Simulations of either sensible heat flux or latent heat flux were compared with its calculations from observed data and with measurements of net radiation, soil temperature and soil heat flux respectively. Results show that this model can be applicable to simulation of energy exchange for summer over various underlying surfaces in the Qinghai-Tibet Plateau.

Abstract:In terms of the canonical variable regression(CVR)of principal component,an interpolation experiment is carried out based on integrated analysis of the change of Jones’ data coverage rate with time,correlation structure and stability between data missing and non data missing fields together with the reconstruction of continuous and homogeneous series of global monthly mean temperature field from 1900 to 1998.The independent sample test demonstrates that the ratio of error variance of data missing to variance of origin data is below 0.40.There are the rough agreements between the original and reconstructed series of global and zonal mean temperature.Linear warming rate of the former gives 0.11℃/(100a)higher than the latter,which may be the result of inhomogeneous distribution of Jones’ series.

Abstract:The influence of equatorial eastern Pacific SSTA on summer circulation in east Asia is studied with the aid of statistical method and model test.On account of the sustained anomaly of the equatorial eastern Pacific SST,the abnormal convection is maintained around the South China Sea to the Philippines,which leads to the continued anomaly of summer circulation in east Asia.The influence on summer circulation in east Asia of the spring and summer SSTA in the equatorial eastern Pacific is not simply a linear superposition,but a nonlinear interaction on a seasonal scale.

Abstract:Five group experiments have been undertaken to investigate the effect of modon heat source variation on drought circulation pattern in Northwest of China.Results show that heat source’s variation on the west and east sides have significant influence on the formation and maintenance of drought circulation pattern in NW China so that the heat sources on the both sides must be considered together as the indicators of prediction.

Abstract:Direct and defuse solar radiations at different heights for clear sky over China have been computed from atmospheric profiles with discrete ordinate method based on the multiple scattering theory.The computed solar radiation at ground are compared with the ground observations obtained at a few national stations of first class.Computed results at heights and the daily variations are also discussed.The purpose of this research is to show that the software,MODTRAN 3,can be directly used to estimate solar radiation parameters for the places short of direct observations.

Abstract:The 300hPa monthly mean temperatures and the 100hPa monthly mean heights derived from the NCEP/NCAR reanalysis data from 1958 to 1997 are analyzed by four data processing schemes,respectively.The results are compared with one another.It is shown that the dependability of the 300hPa temperature data is super to that of the 100hPa height data.The temporal and spatial variations of the temperature and the height fields are also analyzed and the periodic analysis of the two elements is conducted by means of the Morlet wavelet technic.It is found that the first EOF modes of the two fields both have good spatial consistence and temporal persistence,as well as evident interannual and decadal variations with main periods of about 10 years and 2~5 years respectively.

Abstract:The Kuo Anthes scheme of MM4 is not suitable for simulating meso β systems of Meiyu front heavy rain process.The improved Fritsch Chappell(1980)scheme was used to replace the K A scheme in this paper.

Abstract:This paper generalizes a method for class discrimination with the purpose of formulating dynamic random models starting from sample information.Such technique pursues,through the study of the eigenvalues,the reduction of the dimensionality in the representation space.We also describe an algorithm that allows the reconstruction and the approximation by dimensionality reduction for the original information.An illustration with a theoretical model reveals the great compression power produced by this scheme,as well as the goodness of the approximations by dimensionality reduction.Two class case is briefly discussed and an algorithm for reconstruction and classification is suggested.An application to meteorological data shows results similar to the one class case as far as dimensionality reduction goes.A reasonable classification rate is also obtained.

Abstract:By using the NCEP/NCAR reanalysis data averaged over 40 years from 1958 to 1997,the climatic characteristics of the tropical circulation in the two Hemispheres are analyzed.The relations between the onset of the South China Sea(SCS)monsoon and the large-scale circulation are discussed.It is indicated that the updrafts of the Arabian Sea meridional cell tube and the south zonal cell tube arrive in the SCS at the same time in May,which brings strong convective precipitation.Meanwhile,the westerly of the meridional cell tube and the southerly of the south zonal cell tube combine together to form the southwesterly at the low levels,resulting in the onset of the SCS monsoon.The influences of the Tibetan Plateau and the land sea distribution at different longitudes cause the heating differences of solar radiation,which is the direct cause of the summer monsoon onset,as well as,the cause of the earlier onset in the SCS than in the Indian region.

Abstract:The activity of cold air during the torrential rain at 18~26th June,1998 in South China(SC)is analyzed by using the potential vorticity(PV)theory.Results show that under the situation of persistent East Asian(EA)blocking pattern,the southward air from midand high- latitude rushed into the area between South of the Yangtze River and SC three times,corresponding to three times of heavy rain.The air was cut by the Southwest and Southeast warm-moist air flow from low latitude in the vicinity of South of the Yangtze River,and formed a high PV center of cold air.As the result of the interaction of cold and warm airs,the EA temperature field displayed a particular pattern,i.e.,a low center accompanied by two high areas in South and North respectively.

Abstract:Cultivated land classification and dynamic survey were made respectively for five small towns of Changshu,Jiangsu Province in terms of the method of judging between man and computer for the SPOT data of 1994 and 1999.Precision was analyzed by comparing investigation results with aerial photo survey for 1994.Through a comparison between the area from SPOT image of 1999 with that from aerial photo survey of 1994,we have got dynamic changes in land area for class A type with decreasing rate of 18.3‰ during five years for the five towns.Results show that SPOT image is applicable to survey of county level land use,especially when good phase is chosen and effect of small object on land is redressed.

Abstract:This study,taking Jiangxi Province as a test area,was to investigate how to comprehensively use RS,GIS and GPS(3S)technique in monitoring crop growth. Due to the complex hilly terrain in southern China,land use/cover information and GPS measurements were both applied for interpretation of NOAA/AVHRR,extraction of vegetation index and then observation of seedling’s growing status for late rice of double harvest. Finally in terms of iterative auto organized analysis,monitoring of rice growth vigour could be realized from corresponding phase specific NOAA/AVHRR when there are no GPS measurements.Results show that combination of the data on geographical information including digital elevation and land use type with GPS measurements may be appropriate and feasible to better utilization of NOAA/AVHHR data.

Abstract:Based on Shuman Shapiro mesoscale filter,mesoscale analysis under the background of large-scale circulation is undertaken of the heavy torrential rain in Shandong Peninsula during August 11 to 12,1999.Results show that the rain can be attributed to the northward movement and development of a tropical mesoscale cyclone.The invasion of surface cold air to the westward mesoscale depression leads to the development of convective activities and to the development of the tropical mesoscale cyclone.The transportation of lots of water vapor in large-scale circulation provides the energy to the development and maintenance of the strong convection.The surface mesoscale depression center and the wave spot on the shear line is indicative to the rainfall area.

Abstract:With Arctic and Antarctic 1°×1°(longitude×latitude)sea ice area index data and SLP data,it is investigated,by statistical methods,that the variation of sea ice both in Arctic and Antarctic and its relation to atmospheric circulation.It is found that,in the past years,sea ice in Antarctic declines in winter,spring and autumn,while it increases in summer.Sea ice in Arctic decreases in a certain degree in spring,summer and autumn,but its linear trend is not obvious in winter.Sea ices in Arctic and Antarctic have some abrupt changes in spring,summer,autumn and winter.The atmospheric circulation has remarkable differences before and after the abrupt changes of sea ices.

Abstract:Based on 1958~1996 rainfall over 38 stations in Heilongjiang province and 2.5°×2.5° geopotential height at 500 hPa data,the flow patterns in July,August are revealed for flood and drought years with the close relation discovered between the formation of summer flood/drought in Heilongjiang and the seasonal conversion of circulation in east Asia from winter to summer.Four group experiments with the integration of 10 days are carried out by using a barotropic model,which simulate successfully the formation and maintenance of the flow patterns of flood/drought in July,August.The features are also investigated of the heat source forcing relative to the flow patterns of flood/drought.

Abstract:Based on energy balance equation and water-thermal coupled equation for cotton,a multi-layer model of soil-plant-atmosphere system(SPAS)was presented,taking into account not only water and thermal changes both in crop canopy and soil but transfer of water and heat between the crop and soil surface.Simulation was made in the context of the field observations.

Abstract:Aiming at the report problem in development of MIS,according to the DataWindow method in PowerBuilder and database management mode,the authors design and develop a user defined Report Management System. The system can query data in multi-table and multi column,can manage the classification of report,the access of report and the time-limit of report.This paper introduces the principle of designing,and the method of developing the software.

Abstract:Performance management(PM)is one of the important parts in network management(NM).This paper introduces the general process to implement a performance management tool in three aspects such as performance watch,performance management and fault statistics.Espacially,a method to reduce computing error is presented.Finally,some comments to this tool and future plan are given.