Abstract:An axisymmetric,nonhydrostatic numerical model is developed to simulate the mesoscale processes inside a tropical cyclone.Sensitivity of the model to the variables in the sea temperature,laitude and initial conditions is investigated,and the results of the numerical experimentsare similar to previous studies,besides,many simulated charac teristics are consistent with radarand aircraft observation,such as the maximum of vertical and tangential wind ,the inflow concen-trated near the surface,the outward slope of the eyewall updraft'etc. Also,the results show notonly the outward propagation of the meso rainbelts but the inward movement of the convectivering as well,The rate of theinward movement agrees well with the observation,Besides,the model reveals clearly the lifecycle of the ring and the fluctuation of typhoon intensity.

Abstract:Investigated by a two-dimensional semi-geostrophic equation frontogenesis model arethe front generation near a warm bump and the interactions among a large scale baroclinic zone,a warm bump and latent heat release,Results show that,when、a isolated warm bump in the deformation field lies on the warm-air side of the baroclinic zone,a strong frontal zone will emergewithin a limited time;frontogenisis will be speeded up with latent beating available;if a largescalebaroclinic zone coexists with the warm bump,a bi-frontal structure will come into being,whichwill、be maintained if latent heat release continues;the strong frontal zone might appear forst in the bump.especially when the latter is deep and provided with released latent heat The frontogenetic forcing and potential temperature perturbation represent possible mechanisms for the formation ofthe two meso-α scale rainbands near the Meiyn front.

Abstract:Based on ECMWF/WMO data.the November 1985～March 1986 atmospheric lowfrequeney kinetic energy and its flux divergencea are computed and their horizontal distributionfeatures of the winter averages doeumented in detail,togeth,with the horizontal propagation characteristics of the energy sources/sinks revealed.Results show that the maximum kinetic ener gy centers are related to the persistent anomaly cores of action.usually adjacent to the wavetracks of the teleconnections PNA and EU;the robust low frequency kinctic energy sourees(sinks)are located largely at the exit(entrance)of westerly jet:the sources/sinks move predominantly west-and nort h ward at extratropical latitudes in winter,

Abstract:ropical cyclone motion is simulated numerically with a quasi-geostriphic baroclicmodel,The horizontal and vertical structures of large-scale beta gures and their effects on tropicalcyclone motion are analyzed.Results inicate that the quasi-uniform flow(ventilation flow)between the gyres remains related to the tropical cyclone morion.

Abstract:In view of the fact that a climatic time series usuaily contains a tendency to progressively decrease in magnitude,up and downward,in addition to periodic oscillation,ascheme is proposed for successive addition continuation of mean value generating function(MGF),which,together with the continuation sequence of the MGF's period,is screened.Onthis basis,a highly-effective prediction model is established,and examples are given for the modelling and predicting in terms of Huaihe River wetseason rainfall data and global temperature series.

Abstract:The effects of ozone upon summer circulation in the atmosphere are simulated interms of a zonal model in a pa coordinate system,Results show that the upper-level circulationfeatures are improved substantially after the ozone effects are introduced into the model.The involved effects enhance the heating rate at upper levels and for the lower atmosphere ,despite itsnegligible heating there the gas is capable of altering the distributions and values of other heatingcomponents,thereby causing the lower-level circulation to undergo corresponding change.

Abstract:With the aid of a bulky agroclimate dataset,a system of Agroclimate Resemblance Information(ACRI)is developed.This paper presents a brief introduction to its overall design,principles, functions,further development and prospects.Moreover,the system is able to displayrapidly the recent situation of the resemblance research/application and to provide climate datafrom any part of the world kept in it.Also,based on an array of indices randomly selected,agroclimate resemblance calculation and ordering can be accomplished and,on the other hand,it willbe of help to revealing the acclimation sequence and aplicable domain for animal breeds and plantvarieties to be introduced and diffused.Finally'the ACRI will furnish an agroclimatic basis for agricultural techniques pooling、and research.

Abstract:Through 3D nesting of a limited-area fine-mesh model and a T₄₂ L₉ spectral model,numerical study is undertaken of Meiyu-season torrential rainfall over the Changjiang-Huaihe rivercatchment from 0800 BST,10 to 0800,11 July,1991,with the influence of the low-latitude circulation systems and the related vapor passage on the Meiyu precipitation investigated.Results showthat the Bay of Bengal water source and the SW monsoon-formed passage contribute more greatlythan do the source of the South-China Sea and the SE wind-caused passage;both the sources,if-coexistent,produce nonlinear superimpositional effects,causing the enhancement of the rainfall;the change in the vigor of the typhoon and monsoon depression circulations is of importance tothe formation of the torrential rainfall as well.

Abstract:With three GCM's-produced change in annual mean temperature and rainfall on account of CO₂ concentration doubling in the atmosphere as the climatic background,analysis is performed of the expected change of the geographic limits of Chinese firs growing in China and of ecological climate adaptiveness of the commercial timber plantations.It is estimated that the northward shifts of both the southern and northern limits will occur to varying degree,with the area tobe reduced.Further,only a small part of the firgrowing bases now available will keep excellent conditions of the ecological climate.

Abstract:This paper investigates the interannual variation features of April to June precipitationand main difference in 500hPa height anomaly between drought and flood years in South China。Results show that the rainfall has a quasi periodic (2.5 to 3 year) oscillation and a 10 year or sopersistent variation as an interval feature;in the dry and wet years,the January to March 500 hPaanomaly patterns are basically in anti-phase and the April to June patterns differ widely.Comprehensive analysis indicates that the evolution of 500 hPa height anomaly from winter to the following June follows a roughly opposite direction along the 50°N parallel in the two types of years。

Abstract:Through experiments by multiple schemes with the aid of data from 8 ground-hased radiation-sounding stations in India taken from the May-August 1979 MONEX,an expression is formulated for climatological calculation of atmospheric effective radiation at various isobric surfaces for a range of cloudness.Such radiation regime at 500 hPa level in 104 stations throughout the cotintry is investigated with the expression.

Abstract:In the context of May to September 1980～1986 ECMWF dailr 850 hPa data,analysis is mad e of the seasonal mean and low-frequency structures for water transportation in the Asian stimmer monsoon region.Results show that the monsoon system is a complete feature asviewed on a seasonal mean basis,and two relatively independent subsystems(the Indian and East-Asian monsoons)can be identified in the Asian summer monsoon system from the perspective ofthe low-frequency structure.

Abstract:Given in this article is a matrix form of the Box-Jenkins, algorithm for the sum of unconditional squares of the ARMA series with the sufficient conditions for the convergence of thealgorithm and its error estimate derived.Besides,a method for error reduction is presented.

Abstract:The Kolmogorov entropy is calculated in the context of 1 908～1980 monthly meantemperature series from Guangzhou in an n-dimensional phase space after continuation,resultingin the K entropy of 0.1819 and mean predictably time scale for monthly meantemperature being T=1/K,equivalent to some six months.

Abstract:The low-frequency oscillation(LFO)features of East Asian winter monscon circulation are investigated in terms of ECMWF/WMO daily gridded data subjected to objective analysisand with a bandpass filter,Results show that both the horizontal and vertical circulations of themonscon have marked quasi-40-day LFO features. The low-frequency variations of the upper-and lower-level horizontal circulations are influenced largely by the low-frequency vortex systems nearAustralia and in the western tropical Pacific,The low-frequency variation in the zonal circulationis the manifestation of the strengthening and weakening of Walker circulation,with the meridional circulation shown by the localized LFO charac teristics,which links the LFO's of bihemispheric circulations and those of the monsoon circulations at tipper and lower levels。

Abstract:A zonal 5-layer primitive equation model in a p-σ incorporated system is used tosimulate the July flowfield at mid and low latitudes。Focus is on analysis of the simulations ofnear-surface flowfield,meridional and zonal circulations,zonal wind changing with height andcross-equatorial current.Restilts show that there is evident difference between the meridionalcirculations and vertical distributions of the zonal winds in the monsoon and nonmonsoon regions.The influence of land-sea thermal contrast on the atmospheric circulations is clearly revealed by the simulations.

Abstract:Defined in this paper are the conditional and partinl correlation coefficients R(x₁,…,x_k|x_{k-1).R(x1,…,xk∶xk-1)and R(x1,…,xk·xk-1)of K groups of random vectors with comparisons of these coefficients made in a number of situation as well.}

Abstract:The general law of layer's predtictivity is investigated in an agrometeorological con text,whereupon is constrticted a statistical model for the variation in the physiological tendericyversus time and meteorological production as a function of temperature-humidity index(THI)。Moreover,addressed is the change of the productivity in relation to the hot stress index expressed in the form of THI.

Abstract:Comparison is made among three climatological calculation techniques for watertransfer in the atmosphere。They include the instantaneous,averaging and layer-to-layer mean methods.Results show that all these methods are able to display roughly the same direction for water transfer but with remarkable difference in the amount,Comparison indicatesthat the instantaneous method is most accurate and layer-to-layer mean method next to it butwith rather a big interannual fluctuiation in errors.And the averaging technique,though simple,is prone to produce large errors。

Abstract:By using power spectum and bandpass filter,the quasi-periodic oscillation of Northern Hemisphere summer monsoon and Meiyu rainfall over the Changjiang-Huaihe river catchment in 1991 is investigated,with the monsoon's effect on the abnormal preeipitationexamined,baced on the exceptionally torrential rain data from May to August 1991.Resultsshow that there exists a noticeable quasi-24 day oscillation in the monsoon,humidity and precipitation fields。The oscillation found of the summer monsoon occurred chiefly in SW monsoon with its phase 2～4 days ahead of that of rainfall,and its amplitude indicating quite wellthe magnitude of the rainfall event.Hence,the quasiperiodic oscillation of the monsoon canbe utilized in Meiyu rainfall prediction for the river reaches。

Abstract:A mathematic model is constructed to simulate the dry deposition of gases andaerosoas under different conditions,and there with the sensitive factors controlling the deposi tion are examined,thus revealing the features and laws.Results show that the properties ofthe underlying surface,gases the mselves,miscibility and humidity of the particles surfacerepresent the main factors affecting the dry deposition of gases,and the aerosol's diameter,its surface roughness,mean windspeed and atmospheric stability are of significance to theparticle's dry deposition。

Abstract:Investigated are the early atitumn features of six 500hPa teleconnection patterns(with the difference from the winter teleconnections disctissed)and their relation to China temperature field of the season. Results show that the element field of China is marked by the features closely related to the intensity of four of the teleconnections.