Vol.1, NO.1, 1986

Display Method:
The Symmetric and Antisymmetric Distribution of Zonal Mean Geopotential, Temperature and Zonal Wind with Respect to the Equator at 500 and 1000 hPa Levels
1986, 1(1): 2-8.
Abstract:
Based upon Ort’s computations, the symmetric and the antisymmetric components of the mean zonal geopotential, temperature and zonal wind with respect to the equator at 500 and 1000 hPa levels are analysed. It is found that at 500 and 1000 hPa levels these elements are, roughly speaking, symmetrically distributed with respect to the latitude all the year round, and as a whole, regardless of level and element, the absolute values and the undulation ranges of the curves of the symmetric components (hereafter referred to as symmetric curves) are much greater than the corresponding values and ranges of the curves of the antisymmetric ones (antisymmetric curves). Further, the undulation ranges of the symmetric curves, in most cases, decrease from January through July and increase from July through January. But, the corresponding undulation ranges of the antisymmetric curves, on the contrary, increase from January through July, and decrease from July through January. At 1000 hPa, there are variations similar to but not so striking as those at 500 hPa. Finally, the cause of the generation of asymmetric motion are discussed. It seems to be possible that asymmetric distribution of diadatic heating, friction and orography might be the main factors.
A Numerical Experiment on the Change of the Hadley Circulation Related to Anomalous SST
1986, 1(1): 9-16.
Abstract:
In this paper, integrating multiple level PE-spectral model over 24—96 hours respectively, the change of the Hadley circulation cell at 110oE has been simulated for a non-adiabatic process in different SST conditions. It is found that when SST is above normal, the outbreak of cold air southward is weak and there will be an Anti-Hadley circulation at 110oE and when SST is below normal, the outbreak of cold air southward is strong, and the Hadley circulation cell at 110oE will be maintained.
The Prediction of the Intensity of the Subtropical Anticyclone in the Northwest Pacific by a Statistical Method
1986, 1(1): 18-25.
Abstract:
This paper consists of two parts. First, an analysis has been made on the errors in geopotential height at 500 hPa in 48 hours in Eastern Asia in summer 1982 by the operational numerical model given by SMA. It is found that the errors in the middle and high latitudes (to the north of 40oN) are much smaller than that in the subtropical and tropical regions. Second, we have made the expansion of the geopotential height at 500 hPa in middle and subtropical latitudes respectively, and have found that there is a definite relation between them. According to this relation, a statistical method for the 48-hr prediction of the geopotential height at 500 hPa in Eastern Asia in summer has been developed. We found that the 48-hr prediction of the height field in the subtropical region, especially the intensity of the subtropical anticyclone in the Northwest Pacific, is much better than the prediction given by the operational numerical model.
Observation and Analysis of Frequency Spectrum from Lightning Discharge Radiation
1986, 1(1): 26-36.
Abstract:
In Aug. 1984, we observed lightning discharge radiation in Hefei, Anhai Province by using the lightning digital receiver developed by ourselves. The signals were processed by digital filter. Fourier translation and so on with microcomputer. One group of the signals has obvious return strokes, and the other not. 21 typical signals were selected as examples. Some characteristics of signals and their amplitude frequency spectrum were drawn, and were compared with theoretical and other analogue observational results
Numerical Simulation of Microphysical Processes in Stratiform Clouds (I) ——Microphysical Model
1986, 1(1): 37-52.
Abstract:
A comprehensive parameterized model of microphysical processes in stratiform clouds is presented. The transformation rates of the specific water contents and specific concentration of the cloud droplets, rain drops, ice crystals, snow flakes, graupels are deduced based on theoretical and experimental results for 18 microphysical processes, which include condensation, deposition, evaporation, coalescence, riming, aggregation, nucleation and multiplication of ice crystals and autoconversions of cloud-rain, ice-graupel and snow-graupel
The Microphysical Characteristics and the Mechanism of the Precipitation of the Stratiform Cloud in Sichuan Province in Spring
1986, 1(1): 53-58.
Abstract:
A case study on the observation of the prefrontal stratiform cloud precipitation Sichuan in spring was made based on an aircraft measurement with PMS FSSP-100, OAP-2DP and others. It is found that the precipitation from the stratiform cloud was not always stimulated by the natural seeding from high level cirrus. It may be created by the aggregated ice crystals in form needle, sheaths, columus and graupels from riming in stratiform cloud itself, especially in the convective clouds complexes embeded within the stratiform cloud system. The mass growth of those rain embryos is mainly occurred in the negative temperature layer. For a graupel embryo with initial diameter D=600μm, the mass growth in negative temperature layer hold 70% or more of total mass growth.
The Short Climatic Oscillation of the Ultra–long Wave
1986, 1(1): 59-67.
Abstract:
In this paper by using harmonic analysis the anomaly of the sea level pressure of wave number 1—3 along the latitude 60oN and 30oN in summer and winter for 1871—1975 is analyzed, and the interannual variations of the ultra-long wave (wave number 1—3) are discussed. The main results are as follows: 1) The interannual variations of wave number 1 in last hundred years showed a westward propagation in 2—3 cycles. This oscillation had a connection with the cycles of rainfall in East Asia with a period of 36 years. 2) The variations of wave numbers 2 and 3 showed an oscillation of a standing wave. The period 1871—1926 was the first stage during which the position of the trough was situated eastwards, and in the second period (1926—1975) the trough was located westwards. This change corresponded to two different climatic regims in the Northern Hemisphere, and the actives of the centers of actions showed a marked difference. This changes also resulted in the instability of the coefficent of correlation. 3) There were two stages in the sea surface temperature anomaly along 45oN latitude in the Pacific from 1860—1960, which had a connection with the change of the ultra-long wave. The variation of position of the ultra-long wave trough had a similar trend with the interannual variation of the negative anomaly of SST
A Simulation on the Response of the Climate of China to the SST Anomaly in the North Pacific
1986, 1(1): 68-74.
Abstract:
By utilizing the result simulated by GCM of Meteorological Institute of Hamburg University, the response of the model climate of China to the SST anomaly in the North Pacific is analysed in order to understand the cause of formation of climate in China. The sensibility experiment consists of anomaly run simulated by superposing an anomaly called the “east warming and west cooling” pattern to the multiyear mean SST field and control run simulated by without the anomaly. The experimental result point out that the two branches of jet around the Qinghai-Xizang Plateau at 300 hPa in January greatly increases its intensity and the Hadley circulation weakens. Consequently, the at 500 hPa and the temperature pattern at 850 hPa resembles the winter pattern, i.e., the meridional circulation and the north to south temperature gradient are strong accompanying with decreasing of the temperature over most parts of China in January. Nevertheless merely weak response of the humidity field to the SST anomaly in the North Pacific is found, it is in agreement with the usual view that the drought in China in winter is caused by frequent invasion of the dry cold anticyclone from Mongolia
A Modified Palmer’s Drought Index
1986, 1(1): 75-82.
Abstract:
This paper expounded the principle and the advantage of the Palmer’s drought index and its procedure of computation of the index. Based on the analysis of the observational data from Jinan and Zhengzhou we modified the Palmer’s drought index to fit the observation data. With this modified index we have calculated the drought index for 140 stations in China from Jan. 1951 to Dec. 1980. It is found that the computed drought indices are consistent with the descritions on drought conditions in some official publications and with the actual observations on drought conditions by the authors, we have the opinion that the modified Palmer’s drought index is suitable for use in China
The Research on the General Circulation over the East Asia in Summer (a Review)
1986, 1(1): 83-93.
Abstract:
The general circulation over the East Asia in summer has always been one of the main subjects of the research conducted in China. In this paper by basing on the observational studies, theoretical studies and numerical modeling we have a critical review on the topics of (1) the transition of the circulation patterns due to seasonal changes, (2) the centers of action of the general circulation over East Asia, and (3) the influence of the Qinghai-Xizang Plateau on the general circulation over East Asia. Finally, some suggestions are made for further research in the general circulation over East Asia in summer