Abstract:A new Lyapunov function is presented,whereby the sufficient and necessary con-dition of barotropic and baroclinic instability is obtained and thereby the well-known Rayleigh-Kuo’s theorem and Fjortoft theorem are considerably improved,leading to the solu-tion of the barotropic stability problem of inviscid shearing basic flows proposed by Rayleigh(1880).

Abstract:A three-dimensional climate model is used to investigate the climatic effects of aerosols in the boundary layer. Results show that these aerosols could lead to noticeablechange in the climate conditions both of the atmosphere and at the ground. The temperature of the air column rises below 300hPa in contrast to that of the surface and soil. Over the desert areas where the aerosol optical thickness is big,there occur cyclonic differential circu-lations in the horizontal windfields, with change observed in vertical motion. A very goodpositive correlation is found between the changes of precipitation and 300hPa rising. Finally,the physical mechanism of the climatic effects of aerosols is examined.

Abstract:Using ECMWF/WMO daily data of the summer of 1982,the relation of South China rainfall to large-scale water transporting flows and the atmospheric heating environ-ment is investigated.Results show that the intraseasonal(30～60day) oscillation of the flows from the Bay of Bengal and the western Pacific can modulate the South China precipitation and that the rainfall is well correlated with the atmospheric heating field. After the estabil-ishment of summer monsoon the intense rainfall over South Chnia is highly associated with the heating condition of the region,the intensification (weakening) of the apparent heatsource and the moisture sink corresponding to the abundant(deficient) precipitation in thispart of China.

Abstract:In terms of 500 hPa pentad height departures of 14 northern winters and pentad departures of temperature and rainfall of 14 summers for NE China,analysis is carried out ofthe effects of the anomaly of the winter circtilations on that of temperature and rainfall in thefollowing summer for NE China,indicating that the stronganomaly areas of the winter circulations are linked to the centers of atmospheric action or ultralongwave trough/ridge at thesame season. Moreover,correlation analysis shows that the strong-anomaly areas are intimately associated with the abnormality of temperature and precipitation in the followingsummer over NE China,This teleconnedtion of large scale circulation on a 6-month scale isrealized with the aid of PNA and EU wavetrains that cause the anomalies of low-latitude andextratropical atmospheric circulations to be related to and influenced by each other, particu-larlv in El Niño and anti-El Niño years.

Abstract:The CTTRC technique with its realization is proposed based on GMS-4 IR clouddata for quantitatively measuring wet-period precipitation over the Huaihe basins,followedby acase study.

Abstract:In terms of bandpass filtered 500 hPa daily geopotential height data,the monthly mean strength and position of the storm tracks are defined,followed by analysis of the time-varying evolution of the tracks and the jet at the same level along with their relation. Resultsshow that the Pacific and Atlantic storm tracks have significant intermonthly variation intheir strength and northand southward location. They are weakest(strongest)in summer(winter),lying northward(southward)of normal position. In most cases,they are positionedbowartream and poleward of the cores of the jets. Also,breakdown is found both in the jetsand storm tracks, Interestingly,the storm track is sometimes bicored over the Pacific.

Abstract:Part or GMS infrared,visible digital cloud maps and synchronous measurements of rainfall during the 1991 Meiyu wet period are used to investigate the relations of tainfallintensity to the brightness on the IR and visible maps by examining the 2D frequency ofclouds producing precitation of different categories, and based on these relations obtainedthe precipitating clouds(for heavy raingush,rainstorm,hard rain and moderate-light rainfall)are identified in terms of the bi-spectral(IR and visible)thresholds, with total accuracyreaching 73.4% and the acctiracy higher in the case of weak precipitation clouds than ofstrong ones.

Abstract:Included in dealing with the climatological calculation of total radiation in western China lower latitude mountain area are the effects of sunshine,moisture distribution and to-pographic altitude,wherefor an expression Q=Q₀(a + bs₁+cs₁²)is developed,by which the space and time patterns of total radiation are explored.

Abstract:Based on Sawyer-Eliassen secondary circulation equations, the secondary circulations induced by geostrophic/ageostrophic forcings, diabatic heating and total forcing in awinter snowstorm event are investigated. Results show that a proper collocation of these circulations in the north and south and at upper and low levels are favorable for the formation of a snowstorm.

Abstract:This paper presents a 2D nonhydrostatic allelastic meso-γ-scale numerical modelto simulate the planetary boundary layer (PBL)with a moving heat island over the surface.In the experiments we took temperaure △θ_g=60K and 30K,separately,for the island movingat the same speed of 4m·s,leading to strong rising behind the island and a local circulation 3～5km wide for the case of 60K.The maximum rising of order of 80～100 cm·s was mea-sured at the height of 300～400m, In the case of 30K,however.the effects of the moving island on the PBL became greatly weakened as compared to the first case,with no closed localcirculation observed.

Abstract:An one-dimensional unsteady model is developed for the effects of aerosols uponurban nighttime boundary layer temperature. Results show that these particles are responsible for near-surface layer temperature increase,as opposed to the condition at 150m aboveground.

Abstract:A scheme is proposed for calculating the stream function of the mass in meanmeridional circulation in the GCM of low resolution vertically. Results show that for the model Hadley circulation,its seasonal change is identical to that of the real atmosphere.It isfound that,separated from the mean meridional circulation of the model atmosphere in the El Niño year can be an anomalous circulation in close relation to the El Niño-type SST anomaly,which gives rise to the lagging transition of the average Hadley circulation into the northernmid summer type.

Abstract:The spacetime spectral analysis is adopted to explore the variation in the 1980～1983 daily atmospheric refractive index N at 32.5°N. Results show that the index variation isdependent largely upon the eastward-moving weather system and displayed on a medium-andlong-range basis.Further,geographic influence is great,responsible for the distribution of cli-matic regions.

Abstract:With variational principles,a scheme is proposed for preprocessing the Dopplerradar-obtained radial velocity data. Numerical results show that this method can remove the radial component of a small motion and noise from the radar velocity datasets.

Abstract:Following Kuo’s cumulus convection scheme,the contribution of cumulus convection to heating and humidifying a mesoscale convective complex(MCC)is investigated for itsrainfall efficiency,thereby estimating MCC precipitation, Results show that MCC rainfall calculation based on the developing stage is close to the reality both in quantity and distribution such that it serves to make estimation and prediction of MCCprecipitation for 6～12h in advance.

Abstract:Based on 1951～1985 winter monthly mean geopotential height data at 700、500and 100 hPa of the Northern Hemisphere,analysis is done of the anomalies of circulations inrelation to the five teleconnections proposed by Wallace et al.(1981),together with the study of their properties. Results show that these anomalies have an equivalent barotropic structurein the mid to lower troposphere, and become weakened and disappear in the upper troposphere and that anomalies of some teleconnections.e.g.,EU and PNA,have a noticeable relation to each other,with the abnormality persisting for the order of one month for the principal teleconnection patterns.

Abstract:A system of terrain+following coordinates is developed to investigate a 3D flow-field over the complicated underlying surface,and thereby an objective analysis is done of the structure of the Chongqing urban area local circulation on a winter fine day. Results showthat downslope cold air from the surrounding hills flows into the urban region at nighttime hours and changes gradually into a valley wind circulatlon in the afternoon. This local circula-tion plays an important part in the fog generation/dispersion and pollutans distribution ofthe citvy.

Abstract:Based on field experiments and starting from the Soil-plant-Atmosphere Continuum (SPAC)theory,analysis is done of the features of energy and substance comsumption inrelation to the water loss from winter wheat fields in the neighborhood of Nanjing spanningfrom heading to yellow ripening,with the crop transpiration affection physiological and eco-logical factors in the main acquired,together with their relation.

Abstract:Under the assumption that G is let to be a 3-connected graph of ordern(n≥11),it has proved that,if for all vertices at an interval of 2 in between(i.e. ,d(u)+d(v)≥n-1 or|N(u∩N(v)|α+1 or|(u)∪N(v)|≥n-δ+1 holds,then G is Hamilton-connected unless G belongs to some special groups of graphs.

Abstract:This paper presents the climatic characteristics of paddy rice growth over the Iow-latitude plateau of Yunnan,Integration-regression numerical modelling analysis of theyield and meteorology during the growth for various parts of the province gives integrative mathematic expressions for the growing rice sensitivity to the climate,indices of regionalization and space distribution characteristics for the different sections,together with the studyof major climate sensitivity factors with the critical period.On this basis,the rice-plantings chemes are presented for the different climates of the province.

Abstract:Under the assumption that the raindrop size has a Gamma distribution,random function is employed to model and investigate the effects of the variation in the size distribution and rainfall attenuation on the precipitatlon error measured by a common radar and biline polarization radar. Results show that the effects of the latter are smaller as opposed tothe former,and the rainfall attenuation causes the polarization measurement to be overesti-mated for light rain and to show no big influence for heavy rainfall.