空间科学学报

1987 Vol. 7, No. 3

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INFLUENCES OF THE VARIATIONS OF SOLAR WIND STATE ON THE MAGNETIC FIELD FLUCTUATION CHARACTERISTICS IN EARTH'S MAGNETOSHEATH

Wei Feng-si, Feng Hao

1987, 7(3): 169-176. doi: 10.11728/cjss1987.03.169

Abstract(1854) PDF 506KB(860)

Abstract:
Influences of the variations of the background solar wind parameters, Alfvenic Mach number M₁, plasma β₁ value and magnetic field angle 61, on the state and spatial distribution of the magnetic field fluctuations in the Earth's magnetosheath are discussed using the exact solution of MHD shock wave jump conditions. The results show that: (1) M₁ mainly controls the level of the amplitude, the relative fluctuation and the anisotropic degree of magnetic field fluctuations. θ₁ controls the spatial distribution of magnetic field fluctuation characteristics. β₁ value does not produce obvious variations of the state of magnetic field fluctuations; (2) While the state of background solar wind changes, the variations of the state of magnetic field fluctuations behind the bow shock will be asymmetric, this responses to the change of background solar wind parameters, M₁, β₁, almost only occur in the dawn side of the magnetosheath. The dawn side is very active in the fluctuations or turbulences of magnetic field, but the dusk side is stable; and (3) This responses to M₁,β₁ at different places are similar, but to θ₁ parameter, the responses show very different form.

IONOSPHERIC MOTION AND FREQUENCY VARIATION OF RADIO WAVE

Hou Jie-chang

1987, 7(3): 177-184. doi: 10.11728/cjss1987.03.177

Abstract(2304) PDF 498KB(889)

Abstract:
In this paper, Doppler shift of radio wave echoes reflected from a spatially slowly, varying ionosphere is discussed. It shows that a moving reflection surface does not necessarily imply a moving medium. The idea which shows the height of equivalent reflection mirror is not necessarily in deviation region of waves is also discussed. Amethod to obtain the isodensity surface velocity profile from the inversion of ordinary and extraordinary wave Doppler shift is suggested.

CORRELATIVE ANALYSIS BETWEEN SUDDEN PHASE ANOMALIES OF VLF SIGNALS AND SOLAR X-RAY EVENTS

Liu Wan-tong

1987, 7(3): 185-189. doi: 10.11728/cjss1987.03.185

Abstract(1854) PDF 325KB(659)

Abstract:
In this paper, based on correlative analysis between observed SPAevents for VLFsignals and the flux density of solar X-ray bursts, a quantitative relation between the flux of the solar X-ray bursts and height variations of the ionosphere at the time of SPAevents is found. From this relation it is possible to estimate the order of flux density of the solar X-ray burst on the ground using SPA's data, while direct observation data are difficult to attain at the ground level because of absorption of the atmosphere. As an example, a SPAevent of VLFsignals occurred on June, 1982 is calculated. The calculation results are compared with experimental data. It seems that this result is fairly good.

COMPARISON OF MIDDLE ATMOSPHERIC DATA OBTAINED BY CHINESE ROCKETS WITH THE DRAFT OF CIRA 1986

Zhuang Hong-chun, Xiao Guan-quan, Tian Jian-hua, Ma Rei-ping, Wu Yong-fu

1987, 7(3): 190-197. doi: 10.11728/cjss1987.03.190

Abstract(2300) PDF 551KB(930)

Abstract:
Meteorological rocket explorations have been successfully conducted for years in our country. Unique data of wind, temperature, density and pressure in middle atmosphere have been obtained. Acomparison of the measured data with the draft of CIRA 1986 is given. The results show that the temperature data from the Chinese rockets are fluctuating around the mean profile given by the model. The agreement is within the range of deviation of international comparison. The seasonal characters of the wind and the intensities of acoustic gravitational waves obtained from the analysis of our rocket data agree well with that given by the model. Because of the sparse of the measurement data, annual variation and tidal oscillations of the middle atmosphere are difficult to be analysed and compared. Nevertheless, the results of this article still show that the accuracy and resolution of our rocket measurements have reached the level of being within the range of deviations of international comparison, and at the mean time also show that the representation of the middle atmospheric structure above our country by the draft of CIRA 1986 is appropriate.

SOURCE MATERIAL OF SOLAR ENERGETIC PARTICLES FROM THE HIGH CHROMOSPHERE AND OVERA- BUNDANCE OF HEAVY IONS BY THE FORCE- FREE FIELD OF SUNSPOTS

Huang Yong-nian

1987, 7(3): 198-203. doi: 10.11728/cjss1987.03.198

Abstract(2059) PDF 471KB(986)

Abstract:
This paper presents a new idea by modelling the high chromosphere of source material of solar energetic particles. Based on the temperature as determined by the data of overabundance of heavy ions relative to local galactic abundances in solar energetic particle events, the high chromosphere is suggested to be the source of solar energetic particles. According to a great number of observations, the acceleration region of solar energetic particles during solar flares is most likely to occur in the low corona and even up to tens thousand kilometres height. Therefore, the source region of solar cosmic rays is generally not so same as that of the particle acceleration. Moreover, the author presents further a model of mechanism of overabundance of heavy ions in solar energetic particle events. From the model, the heavy nuclei with low first-ionization potentials in the source are preferentially affected by electromagnetic force of force-free field in the frozen magnetic field of sunspot and are transported to sunspot region by this action, their abundances are larger in the acceleration region before the onset of solar flares and are overabundant in solar cosmic rays.

THE LF SKY-WAVE EFFECTS CAUSED BY SOLAR X-RAY FLARES

Huang Ze-rong, Wang Xian-lin, Shen Li

1987, 7(3): 204-210. doi: 10.11728/cjss1987.03.204

Abstract(2181) PDF 422KB(806)

Abstract:
In this paper, 761 events of LFsky-wave sudden phase anomaly (SPA) during solar flares observed at Wuchang Ionospheric Observatory (30°32'40.6"N, 114°21'21.32"E) are analysed. The characteristic of SPAand a quentitative relation between X-ray fluxes and SPAphenomena of LFsky-wave are further investigated. It is pointed out that SPAduring solar flares varies with season and is asymmetric about noon. It is shown that the relation between the SPAand the X-ray logarithmic flux is non-linear. Theoretical results agree with experimental ones.

THE ANALYSIS OF SUNSET WHISTLES AT HEFEI AREA

Ye Pin-zhong, Liu Shao-liang

1987, 7(3): 211-215. doi: 10.11728/cjss1987.03.211

Abstract(1956) PDF 342KB(653)

Abstract:
Based on the data of whistle observations at Hefei (37.73°N, 117.15°E, Geograph.; Geomagnetic latitude 20.60°N), the raising factor, absorption coefficient and lifetime of ducts of whistles around sunset are analized and calculated.

THE AVERAGE AND STORM-TIME BEHAVIORS OF IONOSPHERE OVER MANZHOULI

Liu Pei-jing

1987, 7(3): 216-223. doi: 10.11728/cjss1987.03.216

Abstract(1987) PDF 496KB(886)

Abstract:
This paper presents the reduction results of ionosonde data and NNSS measured data at Manzhouli (38.07 mag. lat.) during 1983. The average behaviors and some anomalies of storm-time variations of the ionosphere above Manzhouli are obtained by analysing the critical frequency f₀F₂ and TEC N_T deduced from differential Doppler data.The results indicate that the behaviors of ionosphere in average show a typical seasonal anomaly and good agreement between the variations of f₀F₂ and N_T.Most of the ionospheric disturbances over Manzhouli is occurred in Equinox and Winter. The positive disturbances mostly happened in Winter, mixing positive and negative ones in Equinox, and negative ones in Summer and Equinox.It is shown that the good linear correlation is existed between the RMS value δAp of magnetic index Ap and the RMS deriations δN_T and δf₀F₂ from the month medians for TEC and f₀F₂ during magnetic storm.

PHASE DETECTION INTEGRAL METHOD FOR MEASUREMENT OF THE IONOSPHERIC COHERENT ACCUMULATIVE TIME

Huang De-yao

1987, 7(3): 224-228. doi: 10.11728/cjss1987.03.224

Abstract(1937) PDF 318KB(1061)

Abstract:
In this paper, a phase detection integral method is presented. An attempt is made to analyse the frequency spectra of the backscattering echo using the simple simulation method and to evel ate the coherent accumulative time of the ionospheric backscattering channel.

THE DETERMINATION OF RADIAL TRACK OF MOVING OBJECTS ON THE GROUND BY HF BACKSCATTER TECHNIQUE

Du Jun-hu, Jiao Pei-nan

1987, 7(3): 229-233. doi: 10.11728/cjss1987.03.229

Abstract(2203) PDF 324KB(628)

Abstract:
In this paper, a method to determine the radial track of a moving object in HFbackscat-ter study is given. In the method, the minimum time delay curve, the time delay of the signal and the Doppler frequency shift of the moving object are sufficient. There is no need to know the ionospheric characteristics of the middle point. Acomparison of the calculated data with experiments is discussed and the possible application of the method is also presented.

AN ANALYSIS OF THE SOLAR CO-ROTATING PERIODIC STRUCTURE WITH GEOMAGNETIC DISTURBANCES DATA

Zhang Xing-po, Zhang Gong-Hang, Qi Gui-zhong

1987, 7(3): 234-240. doi: 10.11728/cjss1987.03.234

Abstract(1994) PDF 443KB(876)

Abstract:
Data of solar wind speed and geomagnetic disturbances in the 20th solar cycle are statistically compared. There seems to be a similarity of the corotating periodic structure deduced from both sets of data. An autocorrelation analysis of geomagnetic index C₉ of 1900-1979 shows that in a fairly long period there exist 13-day and 27-day periodic components. It can be concluded that on the corona, there might be some inherent distribution structures. The reflection of such structures by C₉ index is affected by the level of solar activety and North-South asymmetry of sunspot area.

PLANETARY-SCALE OSCILLATION OF THE EQUATORIAL ANOMALY

Chen Pei-ren

1987, 7(3): 241-246. doi: 10.11728/cjss1987.03.241

Abstract(2294) PDF 360KB(1027)

Abstract:
Planetary-scale oscillation of the equatorial anomaly is drawn from the ionospheric data in Japan and India. The periods of the oscillations are usually between 2 days and 5 days. The period of 15-20 day oscillation is also observed.