Vol.1, NO.4, 1990

Display Method:
Two Methods of Expanding A Scalar Meteorological Element in A Limited–area
1990, 1(4): 337-343.
Two methods of expanding a scalar meteorological element in a limited-area were proposed. One is applicable to the rectangular coordinates, and the other to the spherical coordinates. Also, the problem how to solve the Helmholtz equation in the two coordinates with the methods was discussed.
Numerical Experiments with the Impact of the Plateau on the Characteristic Spatial Structure and Moving Speed of Planetary Waves
1990, 1(4): 344-351.
The impact of the Qinghai-Xizang Plateau as a huge orography on the spatial structure of moving planetary waves is investigated using the 12-layer primitive equation model with p-σincorporated corrdinate. The results show that the Plateau’s dynamic effect is highly correlated with its characteristic configuration. The plateau as a noteworthy factor may result in a complicated change of the spatial structure of moving planetary waves, that is to lead to the phase difference between two waves on the north- and south-facing slope, wave speed change and deformation of the spatial structure
The Stratus Cloud Droplet Number/Size Distributions and Spectral Parameters Calculation
1990, 1(4): 352-359.
The numerical experiments on stratus cloud droplet number/size distributions show that the Gamma function (n (D)=Ade-λD) can be well fitted into the measured spectra. The method of calculating distribution parameters is proposed, and it is simpler and more accurate than the moment method
Preliminary Study of Vertical Distribution of Precipitation Chemistry in Lushan Mountain
1990, 1(4): 360-368.
The analysis results show that the ion concentration in the rainwater increased with reducing of sampling altitude in Lushan Mountain, but the pH value was opposite trend with altitude. Also, the ion concentration of the precipitation in the rear of the high is different from that of the frontal precipitation, and the ratio of the concentration at the root of the mountain to the concentration at the top of the mountain is also different between the two precipitation systems above mentioned. It would be related to the direction of air flow and the distribution of the pollution sources. The contribution of aerosol to in precipitation was 91.0%. The direction of air flow impacted on the concentration of aerosol. The washout process for different weather and ion conditions also was not similar
Observation Results of CCN During the Winter over Urumqi Region
1990, 1(4): 369-376.
In this paper, the CCN features during November to December of 1983 measured by Mee-130 instrument were analysed. The CCN diurnal variation types, the effect of wind on CCN and the CCN supersaturation spectra were discussed
Interannual Variations of Summer Monsoon Rainfall over East Asia
1990, 1(4): 377-382.
Using rainfall data for 30 years over the East Asian region, it can be seen that the main component of interannual variations is the quasi-biennial oscillation(QBO). There is a considerable connection between ENSO and the interannual variations (QBO) of summer monsoon rainfall.
The Relation of Surface Heating Fields over the Qinghai-Xizang Plateau to the East Asian Circulation and the Early Summer Drought in Northwest of China
1990, 1(4): 383-391.
Using the earth–atmosphere temperature difference data set of 60 observation stations over the Qinghai–Xizang Plateau for 25 years, the strength of the Plateau surface heating fields is calculated. Maximum load values derived from EOF are selected from Yushu and Rikaze stations, which are used to roughly represent the characteristics of the whole Plateau. Mouthly mean departure indices of surface heating strength for the two stations over the years of 1958—1987 are calculated. According to the indices, the evolution of surface heating field and its relation to the East Asian circulation and Northwest early summer drought are estimated statistically. The conclusion can be used for a long–range weather forecasting of the early summer drought in northwest of China.
Analysis with Isentropic Potential Vorticity on a Cold Wave in Southeastern Asia
1990, 1(4): 392-399.
The dynamical characteristics of a cold wave in southeastern Asia during 3—8 January 1983 were analysed with isentropic potential potential vorticity (IPV) charts. In the brewing stage of the cold wave there are following three factors that play important role for the formation, intensification and southward movement of transversal trough in the mid-troposphere, and for the enhancement of mid-troposphere cold dome and surface cold high. They are IPV advective process (specially northeastern jet), coincidence of the shear line between northeastern jet and northwesterly with IPV maximum line, and cooling process of upward northwestern flow. We believe IPV charts to be really effective for dynamic analysis of large scale weather process, and they are shown to be a useful tool for weather analysis and forecasting
Impacts of Air Temperature Change on the Agricultural Production and the Countermeasures in Dabeixiang of Tianjin
1990, 1(4): 400-407.
According to the principle of system science, using fuzzy mathematics, statistics and operation research, the impacts of air temperature change on the agriculture production in Dabeixiang of Tianjin were estimated, and the optimal countermeasures against arranging production were proposed. The results show that when the average temperature increases 1.0oC, the double cropping and/or triple cropping in two years lean year schemes would be better than the others, when the average temperature decreases 1.0 oC, the single cropping lean year scheme would be better than the others
An Automatic Objective Operational System for Forecasting Heavy Rain in Hunan
1990, 1(4): 408-414.
An automatic objective operational system for forecasting the heavy rain in Hunan is introduced in this paper. A data bank of eight years from 1979 to 1986 is established. Using the data set the system is tested month by month during the periods. The results show that the historical fitting rate is 86%, the correct rate of forecasting heavy rain is 62% and 59% for June of 1987—1988
Analyses and Simulations for the Physical Reasons of Drought and Flood in the Yellow River Valley
1990, 1(4): 415-421.
The evolution of drought and flood in the Yellow River Valley for the last 500 years has been analysed. Sensitivity experiments as simulated by several famous GCMs to examine the influences of the physical factors on the climatic change in north China have been summarized. Statistic correlation analysis between the drought and flood in the Yellow River Valley and some physical factors for the observed data have been calculated
The Filtering Technique with the Curved Surface Fitting Objective Analysis Method
1990, 1(4): 422-426.
The objective analysis fields obtained using the curved surface fitting in an area have a good property of direct low-pass filtering. In comparison with the other filtering results, it is found that its filtering results are better, and have a considerable corresponding relationship between the mesoscale circulation systems and the weather conditions
A Meso-scale Filtering Method and Its Preliminary Application to the Case Analysis of Satellite Sounding Data
1990, 1(4): 427-433.
A “modified double Fourier-series” filtering method is presented and applied to the separation of meso-scale waves from satellite sounding data. The comparative study of this method and Barnes band-pass filtering method shows that the effect of the former is superior to that of the latter.
The Oscillation of Tropical Height Field and El Nino Events
1990, 1(4): 434-442.
The monthly SST data from the National Climate Data Center (U. S. A) during the 33 years periods of 1946—1978 and the monthly geopotential height data set from Monthly Climatic Data for the World (U. S. A) during the 21 years periods of 1964—1984 are utilized in this paper. It is found that the tropical monthly geopotential height values form 850 through 30 hPa in both South and North America and North Africa, as well as over the pacific Ocean appear the quasi-triennial oscillation and that one to three months after the El Nino events, tropical monthly isobaric height departures from 500 through 30 hPa change from negative to positive values, on the contrary, one to two months after the El Nino, from positive to negative values. The most sensitive region of the global tropical isobaric height field is at Tahiti station
The Climate Features of Spectral Elements of 500 hPa Height in the Southern Hemisphere
1990, 1(4): 443-448.
In this paper, the various spectral elements of 500 hPa height in the Southern Hemisphere are calculated using the 500 hPa grid point height from May 1972 to December 1987, including the monthly mean circulation, zonal kinetic spectrum, meridional kinetic spectrum, transport of the disturbance angular momentum, and the conversion rate from eddy kinetic energy to mean kinetic energy, under the condition of geostrophic approximation. The climate features of the spectral element are analysed, and it is found that the distribution of the first three waves (n=1, 2, 3) gives the fundamental feature of the general distribution, and the location and intentisy of the extreme spots are related to the season.