Abstract:In terms of a few experimental schemes,an expression for downward atmospheric radiation form various isobaric levels under a range of cloudiness is developed in the formG_p=σT⁴[0.536+0.128ln(1+e)]The effects of cloudiness are represented mainly by the corresponding change of temperature and vapor pressure at the related levels. Verification shows that the expression has a 6.3% relative fitting error,and thereby the spatial and temporal pattern of the downward radiation is investigated at 500hPa and in the lower troposphere (500hPa to the ground) by use of the data from 104 radiosonde stations throughout the country.

Abstract:The statistical analysis of precipitation anomalies at 160 Chinese stations in May-August shows that the large-scale distribution of precipitation anomalies in China is significantly correlated with the SOI in the previous year and the correlation is as close as the correlation between the precipitation and SOI in the same year. In the following year of ENSO,significant negative preciptation anomalies are observed in China’s east coastal areas and positive anomalies in most of the other parts of the country.

Abstract:The effect of a prescribed Antarctic spring ozone hole(based on the observed ozone decrease from 1979 to 1985) on the temperature and circulation fields of a two-dimensional stratosphere-troposphere model is discussed. The temperature fell by a maximum of 6 degrees in November at about 17 km at the south pole. The mean meridional circulation induced by this temperature change acted to fill in the hole,though the effect was small,producing a change of 14 DU one year. Since observations suggest a fall in the southern hemisphere wave activity in October in recent years,a version of the model in which the southern hemisphere wave driving is reduced by 50% throughout the year,and in which the ozone hole is also present,is run. The ozone column falls by up to 44 DU at 76°S in November but rises by 12 DU near the equator.

Abstract:In this paper a simplified coupled ocean-atmosphere model is used to simulate the interaction in the earth-ocean-atmosphere system on a seasonal to annual time scale. On the basis of the simulation, an experiment is done to explore the relation between the summer monsoon and SST anomaly.

Abstract:Based on the quasi-geostrophic theory,dynamical diagnosis is made on a dipole Ural block during its persisting period and then some conclusions are drawn.

Abstract:In this paper,a double direction forecasting technique for monthly rainfall is presented by means of the iterative algorithm based on Chebyshev Polynomials. The double sirection consists of both inter - monthly rainfall and interannual rainfall. The optimum values of the prediction method are a forecast ensemble based on the two-direction prediction values. Choice of the parameters and their forecasting effects are discussed for Chebyshev Polynomial forecasts. Particularly,in order to select ideal initial values a detailed list is made, and by numerical tests the double direction forecasting technique based on Chebyshev Polynomials proves to have higher precision than the single direction forecasting technique under certain conditions.

Abstract:Variation of SST and its time-space distribution in the tropical western Pacific and the Indian Ocean are studied by using the comprehensive ocean-atmosphere data set (COADS). The average distributions of SST in the winter and summer seasons over the ocean domain are given and the relationships between the few areas in which SST anomalies are relatively active and the other areas in the domain are discussed. Based on the analysis of the time-space distribution features of SST anomaly,some space distribution patterns and their evolution with time are obtained.

Abstract:In this study, some important characteristics of the winter fog and boundary layer in Chongqing are revealed by analysis of the great number of observational data. It is found that besides the radiation conditions ,the mountain wind ,the two rivers running through the city,the urban heat island and airborne pollutants are all the factors responsible for the formation and development of the fog.

Abstract:The low frequency oscillation(LFO)of the East Asian summer monsoon vertical circulation and its relationship with monsoom activities are analyzed in this paper using the ECMWF data from June 1 to September30,1984,indicating that significant local LFO exists in both the vertical meridional circulation and equatorial zonal circulation and that the LFO of the East Asian monsoon meridional circulation originated from the LFO vertically moving in the middle and upper troposphere at 30°S. The LFO in the southern and northern hemispheres are linked by the LFO of the meridional circulation. Besides,the possible relationship between the LFO of the tropical monsoon and Meiyu occurrence is discussed.

Abstract:In recent years, some experiences of forecasting torrential rain and severe convective weather are acquired by comprehensive analysis of observational data from satellite,radar and ground surface. Yao Zuqing,XiaoWenan et al. predicted torrential rain and severe convective weather over the middle and lower reaches of the Changjiang River by tracking cloud cluster activities in terms of the satellite cloud pictures and summing up the features of five types of environmental cloud fields affecting the torrential rain and severe convective weather there and the evolution processes of these cloud clusters. Du Bingyu et al. designed a nowcasting system for predicting the torrential rain over the Three Gorges of the Changjiang River and the Jingjiang area by using mainly the radar data. In this paper, the signs of the weather element fields and the physical quantity fields affecting the three torrential rain and tornado weather processes occurring in Shanghai on September 3,1983,July 11,1985 and July 26,1983 are examined based on the data from the densely spaced ground observing stations in Shanghai,with a prospect of providing a sound criterion for the prediction of torrential rain and severe convective weather by analyzing the variational features of the surface observational data.

Abstract:The econometric model can be used to estimate and forecast the economic losses in meteorological disasters if they are regarded as endogenous variables and various meteorological influenential factors as exogenous variables. The parameters in the identifiable econometric model can be estimated by the 2SLS method. For estimating the economic losses in disasters we have given a numerical example.

Abstract:In this paper,the effect of the nonstationary,nonuniform perturbation of the wind speed at the top of the two-dimensional stratified PBL on the inner parameters υ. /α and α angle are studied by the numerical method with the effects of the baroclinity process on the results examined. In is demonstrated that the contributions of baroclinity, stratification,nonstationary and nonuniform perturbation to the inner parameters are considerable. The results in the paper improve to a certain degree our knowledge of the parameter method in the PBL.

Abstract:The paper makes an attempt to take ’the mean square of inversion errors=minimum’ as a rule to find out an optimum subset of channels with a few different regression methods in order to set up an optimum least square inversion equation for atmospheric remote sensing,thus avoiding the generation of unstable regression coefficients due to ill-conditioned computations. The effects of regression equations resulting from such regression methods as the optimum subset method,forward method,backward method,stepwise regression (double-F-tested), single-F-tested regression,and fixed-M method,are compared with each other based on actual examples. It is shown that the last two methods suggested in the paper are not only simple in computation and distinct in meaning,but also give satisfying results.

Abstract:Based on the observations for 1991 and the historic data for the years when severe drought-flood damages happened,a comparative analysis is made in this paper. The influences of the onset of the Indian south-west monsoon and the East Asian monsoon, the interplay between the upper-level and low-level monsoon flows, the changes in air temperature over the Qinghai-Xizang plateau and in sea surface temperature,and the anomalous variations of the general circulation and the East Asian monsoon circulation on the drought/flood in the Changjiang-Huaihe valley are discussed. Analysis indicates that the summer monsoon anomaly is an important factor causing the severe drought/flood in the Changjiang-Huaihe valley and its main features are the early onset of the strong southwest monsoon and the late prevalence of the southeast monsoon in the flooding years and the opposite situation in the drought years. It is also found that the characteristics of the confluence of the three monsoon flows,i, e., the position of their confluent point and the orientation of the confluent flows are related with the site of heavy rainfall.

Abstract:There exists a close relation between the effects of urbanization on the urban climatic factors and the processes of the urban climatic disasters. In this paper, the major urban climatic disasters and their damages are examined based on the variations of such meteorological elements as heavy rain,megatherm, fog,etc, in Nanjing.

Abstract:In this paper,the interaction of the systems of different sizes in the course of rain gust in the flood season are studied by applying vorticity equation,thermodynamics equation and moisture equation of different size distributions with the emphasis laid on the discussion of occurrence,development and movement of the subsynoptie scale disturbance vortex related to rain gust and on the diagnosis of rain gust regions.

Abstract:Knowledge of China’s meteorological conditions,which is essential for the further development of the meteorological work, is based upon the understanding of the local situation and history of meteorology in each province, municipality and autonomous region. Thus, weather services at the provincial level are now taking the responsibility of compiling the record books of regional meteorological affairs(QIXIANG ZHI).For lack of experiences in the work initiated just recently, it is necessary to establish both general and specific principles for the compilation. In order to meet this need,some general principles have been presented successively,but no specific principles have been suggested so far.In this paper, four general principles and five specific principles are advanced. The four general principles, such as, progressiveness, truthfulness, subordination and layout, are discussed in some detail. The five specific principles will be dealt with in a separate paper.