Abstract:By use of regular data and methods,meteorological and hydrological features of 2003,1991 and 1954 are analyzed.Results show that the precipitation in the Huaihe river basin during the summer of 2003 much more than the normal,more than 1991,but less than 1954,and therefore was the second biggest rainy year only next to 1954 since 1949;the flood in 1954 was the biggest,one in 2003 the next and one in 1991 was the smallest among the three years.Higher flood peaks,larger fluxes,longer durations and severe disastrous losses are the common features of them,while differences exist in aspects of the intensity and time of precipitation and floods with the eariest in 1991 and the later in 1954 and 2003.As far as the general circulation situation be concerned,the common features for the three years are:the southward shifted subtropical high,and frequent activities of blocking high in the Asian westerlies;the weaker cross equatorial flow/equatorial west wind,thus the weaker ITCZ(east of 120°E);and the stronger low-level jet.The different features are that the east blocking high dominated in 1954 and 1991,while the middle blocking high was active in 2003;the subtropical high in 1991 was similar with one in 2003 but with a smaller area and weaker intensity,and among the three the subtropical high in 1954 was the weakest,smallest,and southest.

Abstract:In this paper,a tornado case,which occurred in Wuwei,Anhui Province in Jul. 8 2003,is analyzed by using the WSR-98D Doppler Radar data and the Lightning Location data.The tornado took place on the left-hand side of a low-level jet,and the large scale background environment dynamically and thermally are favorable to the genese of tornado.From the analysis of the Doppler radar echoes,we found that the tornado was born in a mesoscale(γ-scale) cyclone,which developed from the middle level to low level.The analysis of the lightning location data shows that about 10 minutes before the tornado took place,the lightning rate increased distinctly,and after the occurance of the tornado it fell down and the negative ground flashes were obviously increased.Furthermore,tornado lightning existed in the most lifetime of the thunderstorm.In this paper,some observation facts of the tornado are different from some classical theories.Firstly,radar reflectivity factor is not as strong as the classical result.Secondly,the height of the radar echo of the tornadic thunderstorm is only about 6-9km as high as the common thunderstorm.Thirdly,in the tornado case,the negative ground flashes are more than the positive ground flashes,which is different from the classical theory that the fraction of tornadic storm is dominated by frequent positive ground flashes.

Abstract:Diagnostic analyses are carried out for the Meiyu rainstorm in the Meiyu period from 0000UTC 20th July to 1200UTC 1st August in 1998 and the MM5V3 meso-scale model is used to simulate the Meiyu rainstorm.The results show that (1)this precipitation process can be divided into three periods and the nonlinear subcritical symmetric instability is the main mechanism;(2)the increase of rainfall has a close relation with the increase of the disturbance wind which can often be found before the increase of rainfall,so the increase of the nonlinear subcritical symmetric instability can make the rainfall increase;(3) the nonlinear subcritical symmetric instability mainly occurs at 200hPa and 500hPa which can make the atmosphere from linear symmetric stability to instability.Heavy precipitation mainly occurs at the place between the south side of the maximum disturbance wind field at high or middle levels(200hPa or 500hPa)and the north side of the maximum disturbance wind field at the low level(850hPa);(4) The e-folding temporal and spatial scales of the nonlinear subcritical symmetric instability disturbance are respectively 5-8h and 200-300km.

Abstract:As for the 1km-resolution spatial interpolation of temperature in the area with complex topography,two methods for the interpolation of temperature are presented by the author based on Gaussian weighted method,each of which is appended with a topographic-factor and an error-modifying scheme correspondingly.The method,which can make the resultant temperature distribution match with the topography in the area better was selected.Using this method,and in the area including the mid-upper reaches of the Yangtze River in 2001,the daily temperature's mean absolute error(MAE) of the obtained 1km-resolution graphs of temperature distribution is improved by about 1.2℃ and reduced to 0.43℃ for the mean temperature,and it's root mean squared interpolation error(RMSIE) is improved by about 1.5℃,and reduced to 0.56℃.Apart from above,the daily mean temperature's mean absolute errors of the obtained 1km-resolution graphs of temperature distribution are within 0.77℃through the year.

Abstract:By using the direct solar radiation data measured by a CE-318 automatic sun tracking spectrophotometer,the optical depth of atmospheric aerosols is calculated by using the Bouguer theorem and its variational characteristics in four seasons in Yinchuan area are analyzed.The results show that the optical depth of atmospheric aerosols shows apparently daily and seasonally variations.There are four patterns of daily evolution(0900-1600) BST,and they are:1)the diurnal evolution of the optical depth of atmospheric aerosols are relatively steady;2)the diurnal evolution of the optical depth of atmospheric aerosols shows a general trend of increase;3)the optical depth of atmospheric aerosols exhibits a peak value at noon;4)the optical depth of atmospheric aerosols shows a peak value in the morning but its variation is small at other time.The seasonal variation of the optical depth is larger in winter and spring,smaller in autumn and the smallest in summer.The main component of atmospheric aerosols is dust in spring,and the particles emitted by human beings in winter.As far as in summer, the optical depth and number concentration of atmospheric aerosols are relatively small because of the abundance of precipitation and the plenty of water vapor.

Abstract:By employing the CCM3(R15L9) long-rang spectral model developed on the basis of CCM3 climate model,study is undertaken of the effects of the persistent positive sea surface temperature anomaly(SSTA) in the Northern Pacific ocean on East Asian atmospheric circulation in the early summer.The results indicate that the persistent positive SSTA in the North Pacific indues the warming in the middle and upper troposphere in the Asia-Pacific region between 20-40°N,thus favorable to the weakening and north Jump of the East Asian subtropical westerly jet in the early summer,the strongthening and northward advance of the tropical upper-level easterlies and the northwest Pacific subtropical high;and also favorable to the development of the Asian summer monsoon and the surface mean temperature rising overEast Asian land.All those circulation characters are beneficial to accelerating the season transition in East Asia in the early summer.

Abstract:Making use of the data of June,July and August 2001 and the mesoscale model-MM5V3.5,the capability experiments of summer climate simulation aiming at the eologically vulnerable areas in the west of Liaoning are performed in this paper,and this changes of summer mean tempreture due to the degeneration and resuming of vegetation are simulated.Results show that after the degeneration of vegetation in some areas in the west of Liaoning,the summer average temperature obviously increases while the summer average temperature drops due to the local resuming of vegetation.In the areas around the vegetation change regions,the summer average temperature also alters to some degree.At the same time,the vegetation change affects the temperature and pressure fields aloft.

Abstract:The feasibility for the retrieval of precipitable water(P_W) by using the GMS-5 and surface observation data is discussed.An empirical formula of P_W retrieval using the three channels of brightness temperatures and surface water vapor pressure is presented.And then the parameters in the formula for different seasons are calculated.Test results based on 990 sets of data show that the performance of the formula is higher and its average absolute error,R_MSE and correlation coefficient are 0.1903g/cm²,0.2758g/cm² and 0.97,respectively.

Abstract:This paper presents a means for dividing the agricultural climate districts and harvest risk districts of potato based on GIS technique and climate resource information.The indicators of climate and risk which includes the fail and lost risks for potato growing in the county WulanCabu in the middle of Inner-Mongolia Autonomous Area are given according to the spatial statistic results of multi-natural resources in the county.Meanwhile a prediction method of natural resources distribution on small grids is applied to all cases chosen here.Using CITYSTAR 3.0,the agricultural climate districts and the harvest risk districts are drawn and shown in geographical maps.The district maps can be provided to the Department of agricultural planting and planning and the Department of agricultural insurance for helping them in district choosing.

Abstract:Complete and reliable monthly mean temperature series at 500hPa for 50 stations of the Tibetan Plateau which locate at a more than 3000m height for 1950-2000 are presented by making use of the bilinear interpolation for NCEP/NCAR data.According to the close relation between surface and 500hPa temperatures over the Tibetan Plateau,we design the regression scheme for each month of every station,and make the new regressions supply the lack,and reconstruct the whole surface monthly average temperature of the Tibetan Plateau during the period from 1950 to 2000.The contrast experiment of the regressive effect shows that the regression schemes are complete feasible.The characters of the new reconstructed monthly average air temperature represent the actual ones of temperature over the Tibetan Plateau fairly well.

Abstract:Aiming at the problems of the traditional lightning protection technology,through analyzing lightning theory and triggering mechanism,and by utilizing electric field theory,this paper designs a set of initiative lightning protection system(ILPS),which makes the atmosphere around protected objects being in a passive-excitation discharge state and employs lightning current to induce the atmosphere into a self-excitation discharge state.The paper introduces the theory of ILPS,also elaborates the kernel theory of leading and retaining,then with this understanding puts forward the model of ILPS.And the paper illuminates in detail the structures,features and the relationship of pushing system,leading system and power system in ILPS.The calculated electric field intensity required for ILPS is E=0.69kV/m.Finally its problems and developing directions are also given,and the characteristics and key of ILPS are summarized in the conclusion.

Abstract:In this paper,the relationship between surface net radiation and satellite data is statistically discussed by use of the surface radiation observations and the Visible.Infrared data set from GMS4 at the same time over Shanghai and Beijing area in June and July 1994,and the regression prediction equations are developed for estimating 0800-1700 hourly surface net radiation and 0800-1700 total surface net radiation.And the two models are tested for 1400 1st July 1994 and Jinan area respectively.The result shows that it is feasible to estimate the surface net radiation by use of the satellite cloud picture.

Abstract:In the context of the daily precipitation data of 60 stations in Jiangsu from 1961 to 1999 and the daily reanalysis wind field data from NCEP/NCAR,the spatial-temporal variation characters of precipitation in Jiangsu and the background of atmosphere general circulation during 1st-7th May are analyzed.Results indicate that the temporal variation characters of precipitation are related to the course of summer monsoon onset in the South China Sea;and Jiangsu can be divided into the southern and northern areas of precipitation variation.The distributive characters of precipitation and 850hPa wind field are also analyzed in the year when the extreme precipitation occurred in Jiangsu during 1st-7th May,and it is found that the precipitation lay obviously north of the climatological normal and the subtropical high of the west percific appeared obviously abnormal in the extreme year.

Abstract:Based on the spatial analysis and database technology of the MapObjects and ArcInfo geography information system,the geographical positioning technology for satellite remote sensing information of forest fire-points is studied.By use of 1:250000 geographic data,the technical process and calculations are developed for obtaining quickly geographical information near fire-points in a automatic operational system.Compared with manual geographical positioning,it improves the position accuracy and efficiency for more than ten times in the case of multi-fire points.After running in operation,it has played an important role in forest-fire prevention because it earns time in monitoring forest fire-points and thus gains obvious social and economical benefits.

Abstract:Deriving the quenching phenomena to an initial-boundary value problem in a bounded domain in the Rⁿ for the mean curvature equation with a nonlinear convection term:u_t-div[σ(¨u²)¨u]+b(u)·¨u=0.If u₀∈L^q,q≥n,the solution will quench in limit time.We also give the L^∞-estimate.

Abstract:In this paper,the relevant concepts and sources of uncertainty,and the method to evaluate the uncertainty of measurement are introduced.The difference between measurement error and uncertainty is also defined.In the end,the whole evaluation of uncertainty in measurement is given.

Abstract:According to the characteristics of scientific and technical papers,especially of atmospheric science papers,we analyze the requirement of writing,and mainly explore how to express based on national standards of China,which include quantity and unit,mathematical symbol,figure and table,and references.Finally,some suggestions about the submitting and modification of sci-tech papers are given.