Vol.4, NO.1, 1989

Display Method:
Northern Hemispheric Seven–level Primitive Equation Spectral Model (III) and Its Application to the Medium Range Numerical Weather Prediction
1989, 4(1): 1-12.
In this seven–level spectral model (III), the following physical processed are included. They are: orographic effects (using σ–ordinate) and surface friction, horizontal and vertical viscosity and diffusion of momentum, moisture and heat, latent heat, heating or cooling due to radiation, and cumulus convection. The initialization scheme of nonlinear balance equation is used in the model. By using the daily objective analysis data from ECMWF, the experimental purpose. The verifications of these cases are discussed in this paper. The results show that the forecasting accuracy of this model is comparable with those obtained with some models with high resolutions
A Numerical Simulational Study on Fujiwhara Effect of Binary Cyclone
1989, 4(1): 13-20.
In this paper, the Fujiwhara effect of binary cyclone and the characteristics of the track of cyclone after merging of the binary cyclone have been simulated and studied by using a nondivergent barotropic model. The experimental results show that the Fujiwhara effect can occur only when the initial separation distance between the two cyclones is less than the critical distance which depends on the structure of the cyclone and the relative intensity of the binary cyclone. The merging of binary cyclone, in fact, is the processes that one of them decays and vanishes while the other still maintains. In the case of consideration of βeffect, the resulting cyclone after merging of the two cyclones with the same intensity only drifts along straight line toward northwest, while it travels under the combined effect βdrift and the movement of a top when the two cyclones with the different intensity merge. These results obtained here are in many ways similar to behaviors of the interactions of binary typhoon in the actual atmosphere.
Some Experiments on the Objective Analysis of Incorporating Unconventional Data in the Northern Hemisphere
1989, 4(1): 21-28.
Based on the objective analysis scheme of the grid points of longitude and latitude, some experiments of incorporating unconventional data of satellite wind, reconnaissance aircraft, buoys and surface ship reports have also been analyzed. The analysis quality of this scheme has been examined. The results show that the incorporation of above-mentioned unconventional data is very important for the improving analysis quality. Especially for the Pacific and Atlantic areas where the convention data are relatively sparse, the objective analysis is significantly improved.
A Bandpass Filtering Method and Its Preliminary Application
1989, 4(1): 29-34.
A low-pass filtering method of Barnes-Shapiro’s type has been improved to obtain a bandpass filtering method, which has the good response to the selected mesoscale wave length. This method has been applied to analyze meteorological fields for nine cases of mesoscale cloud cluster over South China in May and June, 1980. The results show that the filtered fields are obviously of the mesoscale nature. The distributions of the fields of several elements are related to the locations and intensities of the cloud clusters six hours later.
The Impact of El Nino Event on Tropical Circulation
1989, 4(1): 35-42.
Using the tropical grid wind data and OLR data set of NMC for 17 years, we have compared the tropical circulation of typical El Nino year with that of the La Nina year. It is found that in El Nino year the strongest convective region which is climatologically located in the equatorial western Pacific is weakened and moved eastward to the central Pacific, and the east—west heating gradient becomes smaller. Therefore, both the Walker circulation over the central—eastern Pacific and the anti-Walker circulation over the western Pacific and Indian Ocean would be weakened. Meanwhile, the El Nino event would also weaken the anti-Hadley circulation over the central and eastern Pacific and Hadley circulation over the American continent
The Oscillation Characteristics of Radiational Parameters over the Zhangye Region During the Summer of 1984
1989, 4(1): 43-51.
A multi–spectral method is used to study medium-short and very-short range oscillation characteristics of radiation parameters observed in the Zhangye region of China in the summer of 1984. Medium-short range oscillation are defined as a sort of the variation occurring on the time scale of 3—5 days: the very-short range oscillations occur over the periods of approximately 30—80 minutes. The quasi-three days oscillation is also found in the thermal boundary layer. These oscillations propagate from west to east within the height range of about 400 hPa. The amplitudes of the very-short range oscillations of the radiation parameters over the Zhangye region vary with a period of 3—5 days, However, there are certain relationships among all sorts of the scales of the oscillations in the atmosphere. The quasi-three day oscillation may be a response to the thermal disturbance on the Qinghai–Xizang Plateau. There seems no distinct relationship between the very-short range oscillation and synoptic systems, but the oscillations appear to vary with the thermal state near the surface and prevalent cloud type
Sensitivity Study of the Effect of Stratospheric Volcanic Aerosol Layer on the Global Temperature
1989, 4(1): 52-59.
The conclusions drawn from this study indicate that the volcanic eruptions make the global temperature decrease and the behavior of the temperature change following the eruptions are related to the locations and seasons of the eruptions. Special attention should be given to the eruptions in the high latitude of the Northern Hemisphere and in the spring or summer seasons. They would bring about the significant cold summer and exert an obvious impact on the global climate changes.
A Method for Detection of the Airflow Within Storms with Conventional Weather Radar
1989, 4(1): 60-68.
A method for applying correlation pattern recognition to determine the displacement of reflectivity pattern between two scans in the radar reflectivity field is described. According to this method, two–dimensional velocity field of storm echo, and internal airflow of storm is obtained by conventional weather radar. Then, the reflectivity fields are computed by use of this method and compared with observed storm reflectivity fields.
A Long–Range Forecasting Model for the Subtropical High Using the Integral Multi-level Recursion
1989, 4(1): 69-74.
In this paper, the advantages of the integral regression analysis and the multi-level recursive forecasting method are first discussed. Then a long-range forecasting model for the characteristic quantities of the subtropical high using the integral multi-level recursion method is suggested and the result of experimental forecast is satisfactory
Relationships Between Tree-–ring and Climate in Changji Region of the Middle of the Tianshan
1989, 4(1): 75-81.
The simple correlation and multiple correlation between the tree-ring chronologies at 6 locations in Changji region of the middle of the Tianshan, and mean temperatures and total precipitations for the growing season at 5 climatic stations around the tree-rings sampled have been analysed. Both data sets are subjected to a canonical correlation analysis. The results show that the two data sets are significantly correlated at the 99.5% confidence level. The correlation between the tree-ring index and the temperature is negative and the correlation between the index and the precipitation is positive in arid and semi-arid Changji region. Also, the one year lag correlation is more significant than the concurrent year correlation. This would probably provide a basis for reconstructing regional climate from tree-ring evidence.
Analysis of the Relationship Between the Acidity and Physical Character of Precipitation
1989, 4(1): 82-87.
Utilizing the monitoring data of the acidity of precipitation obtained by Changchun observatory and other stations in 1983—1985, the relationships among the precipitation amount, precipitation intensity, precipitation type, the seasonal variation of precipitation, the distribution of raindrop size and the acidity of rain have been analysed. Also, the effect of precipitation on the rainwashing pollutant has been discussed
A Review on Some Problems of the Antarctic Atmospheric Sciences
1989, 4(1): 88-95.
The present paper mainly focuses on the Antarctic general circulation, atmospheric radiation and structure near the ground layer, atmosphere–ocean–ice process and its effect on the global climate and Antarctic ozone hole. Then Chinese Antarctic atmospheric scientific expedition and research are also introduced