Abstract:This paper gives a brief description of the formation and development of a two dimensional dynamic-physical climatic model, with which two sensitivity experiments are conducted. The influence is studied of the difference between the two radiation calculation scheme results on zonal circulation changes, together with the effect of meridional eddy momentum flux on the establishment of East Asian Monsoon.

Abstract:Using the Singular Value Decomposition (SVD), relation of the tropical Western Pacific and Indian Ocean SSTA to the Europe-Asian 500hPa height anomaly is analyzed. Results show that in their interraction the space patterns are typically paired with high temporal correlation coefficients between the corresponding pairs at the same period.

Abstract:Based on the triangle truncation at wavenumber 10,a study is made of the topographic influence on the intra-seasonal oscillation (ISO) in terms of a 5-level low-order global spectral model. Analysis of the one-year bandpass filtered data obtained by models with and without topography shows that the effect of topography lies in the intensification of convective activities in the tropical Atlantic and Indian Oceans, thus reinforcing the intensity of the oscillation of the tropical convective heat source/sink, and the extratropical ISO, In addition, the mechanism of the topographic influence on the ISO is examined herein.

Abstract:The features of the periodical variation in the tropical convective activity, its horizontal structure and the 30-50 day oscillation were analyzed with the 1979-1984 outgoing longwave radiation (OLR) data, and the anomaly of winter convection in the El Nino year (1982) was discussed in detail. Results show that the feature of the dual-element state of climate system could be reflected by the seasonal mean activity of convection. The convective disturbance is not marked by a dualelement state but it becomes relatively strengthened in the eastern Pacific during thd El Nino year, yet with a center of action of the disturbance west of the dateling. The 30-50 day oscillation of the convection travels eastward along the equator, crossing the dateline into the eastern Pacific in the El Nino year and trapped to the west in normal years in general.

Abstract:on the basis of the correlation between global radiation measurements and monthly means of surface net radiation flux densities (SNRFD), analysis is done of the correlation of their climatological calculations, confirming roughly their consistency, with a prepared nation-wide chart of annual mean SNRFD with the aid of the regression formula. The pattern agrees fairly well with the results by the residual term of the surface radiation balance expression. Besides, the correlation characteristics are examined between the climatological values of global and the net radiations for slope land, indicating that for the slope <20° their coefficients of the regression equation are in concord with those for a horizontal ground and with the increasing slope the coefficient changes correspondingly.

Abstract:Conditions for the existence of nonlinear Rossby periodic and solitary wave solutions in the atmosphere and oceans are studied with the aid of the phase plane geometrical qualitative theory of a dynamic system defined by the differential equation. The expression of the velocity and some diagnostic relations among the parameters in nonlinear waves are obtained. It proves that characteristic vorticity is restricted, implying that too strong vorticity is unallowable so as to avoid the breakdown of the waves.

Abstract:A 0-2 hour nowcasting model of the strong-convection echo system is established on the IBM-PC microcomputer system in terms of the weather Doppler radar dataset. From the PPI images preprocessed with the model proposed, a group of patches of intense echoes of interset is singled out, from Which a set of eigenvalues is extracted and classified using the fuzzy cluster technique. With the aid of extrapolation of the track a nowcasting is prepared, whereby good results have been obtained on an objective basis.

Abstract:Based on the ECMWF global objective analysis of 7-level mean geopotential height anomaly, a study is made of the simultaneous correlations of the corresponding points of these level with the sea surface level as the base for December, January and February (DJF) and June, July and August (JJA), respectively. Results show that the barotropy and baroclinity change greatly geographically, as shown in the height departures, with remarkable seasonality:the DJF lower troposphere anomaly is marked by higher (poor) equivalent barotropy over the oceans (continent); the upper troposhere circulation anomaly is illustrated by a high-value region of correlation coefficient around the equator and a low area dominating subtropics; the correlation pattern between the circulation departure fields of the low and upper troposphere indicates that a high region is not always over the waters and a strongest negative correlation center arises in the tropical eastern Pacific. Its comparison to the JJA pattern reveals that a particular significant seasonality occurs in Africa and the tropical Indian Ocean with a DJF vigorous barotropic sector and a JJA baroclinic one, respectively.

Abstract:With the aid of the vector dynamic diagnosis in conjunction with correlation calculation, the 500hPa ECMWF daily data are dealt with. Detailed research is done of the problem of propagation path of low-frequency oscillation based on observations and the possible maintenance mechanisms are investigated diagnostically by means of the barotropically unstable energy conversion feature. Results show that the oscillation propagates along three dominant wave-ray paths in close relation with the westerly wind distribution. The maintenance bears some relation to the energy conversion of time mean flow.

Abstract:The paper investigates the teleconnection pattern features of the monthly mean circulation abnormality in the period previous to the wet or dry season with abundant or little precipitation and the teleconnection relationship between the atmospheric circulation pattern and the subsequent dryness/ wetness and temperature anomaly in North Chinal results show that the rainfall quantity bears a close relation to the meridional wavetrain characteristics of the previous-period teleeonnection. By a filtering scale dissociation technique the link between the quasi-stationary planetary PNA and EAP teleconnection wavetrain and the rainfall and temperature abnormalities in the wet season is described, further revealing the energy propagating path with its mechanism of the meridional wavetrain prior to the advent of the rainy span.

Abstract:Time series analysis was made and an automatically adaptative AR model was established by the RLS recurrence method for the random series of rainfed cropped soil water extracted periodically. The simulation and prediction show that this model is of high automaticaly adaptability and of value in soil water management.

Abstract:With the data of the ADAS Sounding System, analysis is made of the winter at Chongqing space-time distribution of temperature, humidity and wind of the atmospheric boundary layer with an approach to the environmental regime for the fog there.

Abstract:The coefficient of regression is obtained by taking the time scale of 30-year, considering the approximate relationship between the precipitation of Beijing and the temperature of Northern Hemisphere as the linear relationship with the auxiliary variable （the global CO₂ concentration） involved, increasing the gobal variation information, excluding the interference of errors. Then the change in precipitation of Beijing when the temperature of the Northern Hemisphere increases by 1℃ is attained to study the change in precipitation in North China, North-east China and Inner Mongolia. Supposed that the global temperature increases by 3℃ when CO₂ is doubled, the precipitation in regions mentioned above will increase by more than 15 percent. And the precipitation in the’area east of Mountain Taihang will increase by 30 percent.

Abstract:Based on the ray theory of geometric optics, study is made of the effects of blockings on the dispersion of Rossby waves, together with the shielding of blockings in the Rossby waves propagation, thereby interpreting why Rossby waves in the regions under the control of certain blockings can hardly be propagated and maintained.

Abstract:Analysis of the occurrence of a torrential rain shows that the zonal heterogeneous stratification around 200hPa jet contributes greatly to the development of internal inertial gravity waves. The torrential rain will develop when the waves propagate where the degree of stability decreases.

Abstract:In this paper, the nonlinear compressible wave is dealt with analytically under the condition of adiabatic frictionless motion of air, indicating that this kind of acoustic wave propagates unidirectionally and along the streamlines (if they are parallel )and shock waves will be formed if the initial field is complex enough. Theoretical results may be of value in explaining some phenomena associated with compressibility of air.

Abstract:By using the mixed polynomial expansion, the conponents of mean and anomalous circulation are analyzed based on the 1951--1985 January and July 500hPa monthly height data with some significant results obtained.

Abstract:Based on ECUM method (equation of continuity combined uniform winds), a harmonic scheme for the spatial distribution of horizontal wind is proposed to retireve horizontal wind from a single Doppler radar data. This scheme is based on the assumptions of the local uniformity and linearh equation of continuity to obtain an ideal wind field. The calculation results are found to be superior to those by velocity-azimuth display(VAD)method.

Abstract:Based on the diagnostic analysis of a raingush event in the Meiyu period over the Changjiang-Huaihe basin, a study is conducted of possible mechanisms responsible for the formation of Meiyu front torrential rain, indicating that it occurs under the conditions of potential stability or neutral stratification and the mechanics causing convection may be either due to conditionally symmetric instability or to potential instability on the equi-M surface. Further, Frontogenetical secondary circulation and sub-synoptic cyclone are the important factors for the heavy rain as well.

Abstract:This paper describes the structure and principle of a crop-land micro-droplet evapotranspirator, the layout and hard-ware arrangement and working state of the remotely measuring water-supply. Finally, the design of the data collecting and processing system is illustrated.

Abstract:The possibility of heavy rain suppression with its good prospects is explored by dwelling on the principles of artificial suppression of hailstorms and localized snowstorms and mitigating typhoons by experiment and considering some basic problems of rain-making at present.