1987 Vol. 7, No. 4

  Previous Issue | Next Issue 
Display Method:
Cover
High Solar Activity in Early February, 1986 Ⅰ. The Active Region 4711
Wang Jia-long, Xia Xiao-ping, Tang Bai-sheng, Kun Fan-xi
1987, 7(4): 247-254. doi: 10.11728/cjss1987.04.247
Abstract(1985) PDF 1046KB(705)
Abstract:
Using observational data of sunspots, Ha chromospheric region, solar flux at 10.7 cm, solar magnetic field and soft X-ray emissions in 1-8 Å, the evolution of the Active Region 4711 which produced major flares early in the February, 1986 is described. The characteristics of the evolution of the region are discussed and the conclusions are as follows:(1) The sunspot group in the region is classified as DKCor EKCand Delta in the main phase of its development, and forms a compact, complicated and strong magnetic area during its main active stage.(2) Two large flares on 4th, February (3B/X3) and on 6th, February (3B/X1.7), respectively, occurred in the beginning stage of the descending phase of the sunspot group. The lifetime of the descending phase is about two times that of the ascending phase of the sunspot group.(3) The rotation of the sunspot group seems to be the energy mechanism for the heating and flares in the region. The rate of generation of magnetic energy estimated is 6×1027.6 erg/ sec and 5×1032.6 erg/day for the period from 3th to 4th, February, and 4×1027.6 erg/sec and 3.4×1032.6 erg/day for the period from 4th to 5th, February. The most part of the generated energy would be taken away by the Alfven weve, and a small part of it is enough for flares.(4) Frequent activities of Ha filaments in the region are the precursor of a large flare. The chromospheric fibers arranged in good order in the region should imply a strong transverse field.(5) The daily radio flux at 10.7 cm estimated for the active region has two peaks. One of them coincides with the peak of the area of the sunspot group. The other coincides with the CMPof the sunspot group. The daily minimum flux obtained from the soft X-ray plot by GOES-5 is assumed to represent the state of thermal coronalplasma. Two peaks of the flux are not to coincide with those of 10.7 cm flux and the sunspot area. The minimum flux of the soft X-ray (1-8 A) seems to be affected by large flares strongly.
The Kelvin-Helmholtz Instability at the Magnetopause (Ⅲ) Transport of Energy and Momentum by Compressional Unstable Waves
Pu Zu-yin, M. G. Kivelson
1987, 7(4): 255-261. doi: 10.11728/cjss1987.04.255
Abstract(2161) PDF 445KB(595)
Abstract:
Assuming the Earth's rnagnetopause to be an one dimentional tangential discontinuity, the transport of energy and momentum on both sides of the rnagnetopause caused by compressional Kelvin-Helmholtz unstable waves are investigated. The physical mechanism is also discussed. The calculations show that the Kelvin-Helmholtz instability can indeed play an important role in the coupling processes between the solar wind and the magnetosphere.
Adaptive Control of Scientific Balloon-Borne Gondola Attitude
Yan Yan
1987, 7(4): 262-271. doi: 10.11728/cjss1987.04.262
Abstract(2405) PDF 572KB(651)
Abstract:
The uncertainty of parameters of the mathematical model for the control system of balloon-borne gondola attitude is analysed in this paper. The effects of such uncertainty on the system performance are also verified through digital simulations and experiments. To search the ideal control characteristics, a model reference adaptive control for gondola attitude is developed based on Popov's hyperstability theory. This paper presents the discrete adaptive algorithm which gives time varying adaptive gain. Large amount of digital simulations are conducted accordingly. The results show the advantages of this new method over the traditional one in coping with the problems such as parameter variations over a wide arrange, unknown parameters and nonlinearities. The new approach also proves to have kigher adaptive speed and to be implemented more easily as compared with other adaptive control methods.
Observation and Analysis for the Outburst of the Halley's Comet
Chen Yien-kang, Chen Pei-sheng, Gao Heng
1987, 7(4): 272-277. doi: 10.11728/cjss1987.04.272
Abstract(2673) PDF 382KB(947)
Abstract:
During Mar. 20-Apr. 3 of 1986 a photoelectric photometry for the Halley's comet is taken by using the 60 cm telescope at Yunnan Observatory. The diaphragm used was 2 mm which corresponds to a field of view about 33". Six standard narrow filters were used in the observations.It is obvious from these results that in the comet there was a violent outburst which occurred after Mar. 21 but before Mar. 26. During the period of this outburst the magnetudes in the bands of C3, CO+ + N2+ and two continua were much brighter than before and after, even brightening up to 4.41 magenitudes in the band of CO+ + N2+. By contrast, the variations in the C2 and CN bands were quite small. After Mar. 26 everything recovered to normal.In its analysis and discussion about this outburst phenomenon, the possible mechanism and chemical reaction processes involved is present.
Hα-SSHG Observation and Research of the Flare Loop of May 21, 1984
Li Qiu-sha, Gu Xiao-ma
1987, 7(4): 278-284. doi: 10.11728/cjss1987.04.278
Abstract(2324) PDF 815KB(663)
Abstract:
The Ha spectroheliograms of the limb flare loop prominence which erupted on 1984 May 21 have been taken with the Ha spectro-spectraheliograph (Hα-SSHG) of the Yunnan Observatory of the Chinese A cademy of Sciences. By combining them with the Hα chromospheric observations, the process of development and the chromospheric and spectral morphological features of the event are given in this present article. A qualitative approach to the macroscopic motion of matter of the flare loop is carried out. The observations can be well explained by means of a proposed two-loop system model.
The Study of Main Ionospheric Trough from Multi-station Observations
Cao Chong
1987, 7(4): 285-289. doi: 10.11728/cjss1987.04.285
Abstract(2098) PDF 346KB(858)
Abstract:
This paper presents the principal characteristics of main ionospheric trough with analysis of observational data from four ionosonde stations located between invariant latitudes A = 46-70°S. The results show following properties of main ionospheric trough: (1) the trough manifests one-self mostly in winter night; (2) the trough has two features: low electron density and large virtual height, (3) the characteristics of equatorial edge and poleward edge of trough are different; (4) the trough is in unceasing motions and variations during night.
The Inquiry of the Prediction of the Short Wave Fadeout by the Open-loop Threshold Autoregressive Model
Zhang Gui-qing, Wang Yan-lin
1987, 7(4): 290-296. doi: 10.11728/cjss1987.04.290
Abstract(2132) PDF 424KB(669)
Abstract:
The open-loop threshold autoregressive model is used as a method to study prediction of short wave fadeout in this paper, based on a relation that short wave fadeout strongly relies on intense solar activity.The peak of daily flux of the strongest 2800 MHz radio burnt is chosen as predictor. The medium-term, short-term forecasting verifications for Jan.-June, 1980 and Jan.-Feb., 1980 show: for medium-term forecasting (one month ahead) this method is better than the empirical method, but it is quite difficult to forecast the predictor which is required first in the method; the short-term forecasting (three days ahead) using this method has better forecasting effect.
A Study on the HF Radar Illumimated Area
Huang De-yao
1987, 7(4): 297-305. doi: 10.11728/cjss1987.04.297
Abstract(2269) PDF 545KB(875)
Abstract:
In this paper, a method of estimating the HFradar illumimated area and the various factors, affecting the area are discussed. An approach of selecting the operating frequency for the optimal illumimated area is also presented.
The Variations of Galactic Cosmic Ray Intensity and the K Category of Magnetic Disturbances
Ye Zong-hai, Lu Xing-tang, Zong Qiu-gang
1987, 7(4): 306-313. doi: 10.11728/cjss1987.04.306
Abstract(2285) PDF 528KB(1078)
Abstract:
The relationship between the variations of galactic cosmic ray intensity and geomagnetic storms from 1966 to 1983 is studied in this paper. The variations of the cosmic ray intensity during a sudden commencement pulse Si doesn't show an obvious decrease. Avery small Forbush decrease appears during gradual commencement storm Gc. On the other hand, there is a very obvious Forbush decrease during sudden commencement storm Sc. Then Sc storms are classified into SA, SB, SD. Sd and Sb storms on the basis of Kindex. The results of analysis show that Forbush decrease of cosmic ray intensity during SA storms is the most obvious and the decreasing rate and recovering rate are also the fastest. The amplitutes of Forbush decrease are descending in the order of SA, SB SDand Sd storms. Their decreasing rates and recovering rates become slowing in the same order. But the cosmic ray intensity during Sb storms has no obvious decrease. According to corresponding relationship between Kcategory of magnetic disturbances and. interplanetary disturbances, a relation between cosmic ray intensity variations and interplanetary disturbances is obtained.
Identification of Heavy Cosmic Ray Nuclei Recorded by a Satellite Borne Chaoyang No. 1 Polycarbonate
Kang Tie-sheng, Zhai Peng-ji
1987, 7(4): 314-320. doi: 10.11728/cjss1987.04.314
Abstract(2284) PDF 413KB(882)
Abstract:
In this paper a method based on relation of past distance of particle in SSNTDto atomic number of the particle for identification of heavy charged particle is presented. The atomic number and the energy of the heavy cosmic ray nuclei recorded by Chaoyang No. 1 polycarbonate borne in a Chinese satellite are determined with this method.
The Analysis for Spectral Reflectance Characteristics of Targets under Satellites and the Automatic Recognition of Cloud
Wang Li, Xu Gen-xing, Hu Wen-zhi
1987, 7(4): 321-326. doi: 10.11728/cjss1987.04.321
Abstract(2006) PDF 556KB(755)
Abstract:
A method for real-time automatic classification of targets and the automatic control of camera shutter are discussed. The physical model of computing the radiance is presented, the influences of atmosphere is considered and the spectral reflectance characteristics of five kinds of targets is analyzed. The radiance of 34 tar.gets at sorts of atmospheric conditions are computed with the model. The best wavebands, the classification functions and classification flow diagrams for five kinds of targets are determined. The problem of distinguishing cloud and non-cloud is studied. Ten Landsat MSS pictures are measured with the TD504 densimeter. The radiance distribution chart is similar to the result of calculation. How to realize the real-time automatic recognition of cloud on the satellite is also discussed.

Journal Introduction

ISSN 0254-6124       CN 11-1783/V

Copyright © Editorial Office of Chinese Journal of Space Science.  京ICP备08100722号

Supported by: Beijing Renhe Information Technology Co., Ltd.  

x Close Forever Close