Abstract:Th is paper concerns local infl uence on regression estima te precision wit h small modelperturbation available. Four statistics are proposed for describing the influence, followed by giving the direction the maximum local effect occurs under three modes of perturbation, with thegreatest absolute component related to the point of intense influence. Finally,a numerical exam-ple is presented to illustrate the diagnosis of the point.

Abstract:Investigation is performed of the variance of intraseasonal oscillation(ISO) in theECMWF 1980～1986 averaged and 1980 gridded data of low-level zonal and meridional winds,resulting in their respective ISO vigor features and the differnece between low latitudes and extra-tropics, thus providing an approach to the interannual difference in summer winds in the frame-work of dynamic diagnosis and theoretical research.

Abstract:In the context of data from 34 winters 1957/1958 to 1990/1991,a one-point correlation scheme is adopted to examine the major features of monthly mean 30 hPa teleconnection patterns and the intensity indices in the year, with their synoptic dynamic implication and their asso-ciation with subsequent climate anomaly in China explored.

Abstract:Based on the gray scale distribution on satellite cloud pictures(SCP),the gray levelcooccurrence matrices are dealt with, followed by cloud texture features sampled for identifying their characteristic quantities. Thus,the equation of automatic SCP classification is establishedfor the purpose of microcomputer grouping.

Abstract:The P-σ five-level primitive equation model is adopted in connection with a vegetation parameterizat ion scheme to invest igate atmospheric response to Tibetan heat source with vegetation available and without. Evidence sugests that with vegetation present,latent heat flux isstreng thened into the air, thus enhancing the thermal depression over the highland,thermalwind in the north and monsoon circulation on the south side,thereby causing increased rainfall inSE China.

Abstract:Using the developed climatological calculation scheme for components of ground heatbalance and in the context of data from six heat-balance stations of China,investigation is performed of the heat source distribution features on a national basis along with analysis of the waysthe ground heats the atmosphere and the parameterization of the sources. Evidence suggests thatthe monscon-climate background, latitude,terrain and ground humidity are the major factors determining the surface heat source features On an annual basis, ground latent heating represents the main form in the moist and semi-moist regions and the sensible heating is dominant in thearid area of Nw China.

Abstract:Effects of the mixed layer depth, windspeed and stability on winter surface SO₂ con-centration distribution in the city of Yinchuan, NW China are investigated by use of the solutionof Eulerian advective diffusion equation together with the closed scheme of K-mode l.Resu ltsshow that the surface concentration would be reduced by 40%～75% under the extremely unsta-ble stratification(category A) if the depth increased by 250 m, compared to 20% reduction witha 200 m increase in the case of stable stratification(category F).The strongest diluting effect isrevealed: the SO₂ concentration will be diminished by 90%in the west part of the old city as themixed layer depth grows by 250m and the wind by 3.8m·s^-1, and when atmospheric stratifica-tion changes from category F to A and maxima of the depth and wind are confined to 650m and 4m·s^-1, respectively.

Abstract:In terms of T_BB data and associated physical quantities,diagnosis was made of thecauses of the flood causing rainstorm for July 2～6,1993, deriving several structure features ofthe weather system responsible for such torrential rain and characteristics of the T_BB field employed.

Abstract:The spatial and temporal variations of all components of heat balance in a paulownia-crop field are examined in detail using actual measurements. Results show that in such a field anda control plot the latent heat flux(LE) remains predominant,sensible heat flux(H) is less than LE but higher than Q_s(soil heat flux);all components inside such an intercropped field are smaller as compared to the control plot but LE and Q_s account for a higher proportion in net radiation(R_n);the tree belt has its effect on the components dependent on the intercropping structure andmeasuring site. Finally, water use efficiency(WUE) is computed of wheat and cotton in the intercropping and the value is found to depend on the variety and its growth duration and to belower in the control plot.

Abstract:A dynamic model of wheat dry matter accumulation is established on biological principles. The model takes into account the stand shape,light distribution in the population,its netplhotosynthesis,respiration,and distribution of assimilated preducts. Obtained by feeding simpleparameters into the model are results of net photosynthetic rate,eigenvaiues of in-colony lightdistribution and net photosynthesis, respiration,and dry matter weights in leaves stems,rootsand ears. The model is found to be of easy use.

Abstract:Based on agrometeorological and fuzzy principles in examining the climatic suitabilitydegrees of tea growth in Nanjing area, the climatic adaptability is investigated for neighboring counties and suburbs with the climatic suitability states presented and meteorological effect on theyield given for different harvesting periods.

Abstract:Based on 1980～1987 temperature, pressure and humidity soundings measured inNanjing and its surrou nd ings an expression is formulated for the vertical d istribution of atmospheric refractivity index and used to calculate the distribution parameters, fitting errors and Nunit vertical change gradients at a range of climate intervals, Results show that the annual meanvertical parameter differs slightly at these intervals but they are different considerably one fromanother on a yearly mean basis; The vertical distribution parameters differ from each other greatly on a monthly mean basis for each year, showing pronounced seasonality. The distribution ofthe monthly mean parameters in each of the years gives a clear picture of characteristics of climatic intervals, the interannual seasonal and intermonthly characters. Finallv,a muItivariant statistical prediction model is constructed with random vibration phases of a time series considered andused to make forecasts of the vertical distribution of monthly mean parameters for each of the vears.

Abstract:Using visibility theory and the principle of the binocu lar polarized-light visibility meter,the measuring principle is discussed with a new method developed for nocturnal visibilitymeasurement.Atentative field contrast test was performed with the results presented in this paper.

Abstract:Research is carried out of six rainstorm events during 1980～1983 Meiyu periods, occurring in Anhui based on the 117.5°E section, Evidence suggests that the Meiyu front is usuallyaway from ground without pronounced frontal features at low levels, and that a“precipitation-caused front”is often observed On the s outhsidewhen abeldikethunderstorm rainfall occurs inthe near-surface layer,Apreliminary study is undertaken of the genesis and evolution of the precipitation-caused front alongside detailed analysis of meridional circulation features at variousphases.