1990 Vol. 10, No. 2

Display Method:
The Severe Geomagnetic Storm Group Generated by the Solar Activities in March 1989
Zhang Gong-liang, Gao Yu-fen, Nie Hua-shan, Li Zhuo-hua, Zhang Qing-hua
1990, 10(2): 81-88. doi: 10.11728/cjss1990.02.081
Abstract(2008) PDF 574KB(931)
Abstract:
Characteristics of the series of severe geomagnetic storms generated by several extraordinarily large solar flares occured in a super active region in March 1989 are analyzed in this paper in association with the location and importance of parent flares. The storm series consisted of at least four independent storms. The most reasonable parent flares for these storms can be selected from the flares with optical improtance equal to or greater than 2B, X-ray classification being X, and duration longer than 1.5 hours. The morphology of geomagnetic storms changed systematically as the flare region rotated from the east to the west of the helio-graphic central meridian, showing obviously the central meridian effect and the east-west asymmetry in the dependence of storm morphology on the flare location.
The Excitation of Alfvén Waves by Newborn and Pickup Ions
Mao Ding-yi, C. S. Wu
1990, 10(2): 89-95. doi: 10.11728/cjss1990.02.089
Abstract(1603) PDF 420KB(896)
Abstract:
The time-asymptotic distribution function of continuously created newborn and pickup ions in solar wind is obtained by solving the quasilinear kinetic equation in which we have assumed that the turbulence consists mainly of Alfvén waves. The stability analysis of obliquely propagating Alfvén waves is carried out.The distribution function is found to be anisotropic in velocity space and consequently can result in the excitation of Alfvén waves via wave-particle interaction processes. The growthrate Is the highest in the case of parallel propagation.
A Discussion on the Splited Phenomenon of the Rays or Streamers in Type I Cometary Tail
Li Zhong-yuan
1990, 10(2): 96-100. doi: 10.11728/cjss1990.02.096
Abstract(1631) PDF 374KB(895)
Abstract:
In this paper, the splited phenomenon of plasma rays or streamers is already discussed. By means of MHD theory, it is pointed out that the splited phenomenon results from the space plasma turbulence. Aqualitative analysis is given in the article, and a quantitative analysis-as well. Thus the splited phenomenon of rays in plasma tail, is explained reasonably.
Numerical Study of Electrostatic Ion Beam-Density Drift Instabilities in the Geomagnetic Tail
Zhou Guo-cheng, Cao Xiang-dong
1990, 10(2): 101-106. doi: 10.11728/cjss1990.02.101
Abstract(1788) PDF 420KB(1337)
Abstract:
The mechanism of the generation of the broadband electrostatic noises (BEN) in the plasma sheet boundary layer is studied in this paper. The model plasma consists of warm background electrons, warm earthward ion beams and cold tailward ion beams. It is shown that electrostatic ion beam-density drift instabilities can be excited in the broad range of the frequency, the peak growth rate is found in the low frequency region at the large propagation angle, and the considerable growth rate in the high frequency region at the small propagation angle. The direction for the peak growth rate is determined by the ratio of the ion beam velocity to the density gradient drift velocity. The results are consistent with observations of the magnetotail BEN.
LIQUID SLOSHING IN SPHERICAL TANK WITH SPACER AT LOW GRAVITY ENVIRONMENT
Wang Zhao-lin, Cheng Xu-duo, Quan Bin
1990, 10(2): 107-119. doi: 10.11728/cjss1990.02.107
Abstract(1705) PDF 616KB(1207)
Abstract:
In this paper, the sloshing of liquid in a spherical tank with spacer is investigated under low-gravity conditions. Unsing the method which concerning a kind of charateristic functions, expanded into polynominal expressions, the free and forced-sloshing problems are solved. The natural frequencies of liquid sloshing are obtained. The equivalent mechanical models of liquid sloshing are given. The moment and force of liquid acting on tank wall are derived. The numerical results are compared with the ones of spherical tank without spacer, and the advantages of spacer are shown.
Numerical Simulation Study for Multiple Shocks
Huang Lin, L. C. Lee
1990, 10(2): 120-159. doi: 10.11728/cjss1990.02.120
Abstract(1478) PDF 627KB(961)
Abstract:
The multiple shocks, which includes the intermediate shock wave, is studied by means of a one-dimensional hybrid particle code. Four cases are simulated, which can be classified into two types: (1) double shock composed of the fast and intermediate shock waves (Cases Aand C) (2) triple shock composed of the fast, intermediate, and slow shock waves (Cases Band D). The numerical results show that the multiple shocks are unstable, and they tend to-evolve to the rotational discontinuity of the magnetic flow and MHD waves. That the left hand circular polarized wave gradually develop in the upstream region of the shock is another important feature of the results. In this paper, possible cause, which leads to instability of the multiple shocks is discussed briefly.
Some Investigations on Positive Phase Ionospheric Disturbances
Huang Qing-ming
1990, 10(2): 130-134. doi: 10.11728/cjss1990.02.130
Abstract(1411) PDF 335KB(935)
Abstract:
In this paper, based on the data from five Chinese Stations, the positive phase ionospheric disturbances (f0F2 enhancement) are studied. Their temporal and spatial variations, and their relations to geomagnetic storms are obtained. The mechanism of the positive phase disturbances are also discussed.
A COMPARISON OF THE MAIN IONOSPHERIC PARAMETERSOVER CHINA WITH IRI
Liang Shang-qi
1990, 10(2): 135-140. doi: 10.11728/cjss1990.02.135
Abstract(1690) PDF 266KB(1179)
Abstract:
By using the ionosonde data observed at several observation stations in China, the observed values of f0F2, f0F1 are compared with that of IRI-86. The study showed that there exist a systematical and obvious deviations between them. The deviations for E- and F-region are somewhat small. However, the deviation for F2-region is considerably large, even being up to 60% in some cases. The deviations show clearly diurnal, seasonal and solar activity variations. In general, the relative deviations for f0F2 in the night time, summer and active solar zear. Moreover, the deviations become larger with decreasing latitude, and the values calculated from IRIare usually larger than the observed ones.
Stratospheric Winter Warmings and Planetary Waves in the Atmosphere
Tian Jian-hua
1990, 10(2): 141-148. doi: 10.11728/cjss1990.02.141
Abstract(1733) PDF 528KB(652)
Abstract:
In this paper, the atmosphere temperature at (67.5°N, 100°E) and (42.5°N, 100°E) at 10 mb and 0.0827mb levels from the end of 1978 to 1982 is analysed by using NIMBUS-7 SAMS GRID-Tdata. The main features of the stratospheric winter warmings are obtained. It is shown that the temperature increase reached 65Kin a few days at (67.5°N, 100°E) at the 10 mb level in the winter 1978/1979 and the winter of the beginning of 1981. The results of the spectrum analysis of the stratospheric sudden warmings indicate that there exist strong planetary waves with periods of "16-day", 32-day" and "21-day" at high latitudes in winter stratosphere. There are 20K temperature increase at middle latitude during stratospheric winter warming. There exist planetary waves with periods of 16, 8 and 5 days in the mesosphere at middle latitude all the year. The results of the temperature variation with the longitude at different latitudes for both hemispheres are given. It is revealed that the middle atmosphere temperature often varies obviously with the longitude at high latitude in winter, the amplitudes of wave 1 and 2 are large, and they reduce gradually from high latitude to low latitude. It causes the stratospheric winter warmings with amplitudes of wave 1 and 2 increasing sharply in a few days in winter middle atmosphere.
New Formulas for the Prediction of Tropospheric Refraction of High Altitude Targets
Xie Yi-xi
1990, 10(2): 149-155. doi: 10.11728/cjss1990.02.149
Abstract(1501) PDF 421KB(1080)
Abstract:
For a high altitude target like a satellite, the prediction formulas of the, bending angle and distance error due to ray refraction in troposphere are obtained, which can be used to predict the tropospheric refraction for elevation angles higher than 1° and are relatively accurate and simple.
DISTRIBUTION OF Es OCCURRENCE PROBABILITY IN THE SUMMER OVER CHINA (f0Es>7MHz)
Li Yu-hui
1990, 10(2): 156-158. doi: 10.11728/cjss1990.02.156
Abstract(1625) PDF 198KB(696)
Abstract:
In this paper, a statistics is made on the Es, data, obtained from ionospheric observation in China. The results, drawing in distribution map of Es, occurrence probability in China, are analyed and compared with the Chinese part on the world map provided by CCIR. It is suggested that certain correction may be made to the Chinese part on the world map.