空间科学学报

1992 Vol. 12, No. 2

Previous Issue | Next Issue

Select articles

Display Method:

Cover

ENERGY DEPOSITION OF NON-THERMAL ELECTRON BEAM IN FLARE LOOP

Lin Hua-an

1992, 12(2): 81-88. doi: 10.11728/cjss1992.02.081

Abstract(1881) PDF 634KB(1076)

Abstract:
In this paper,the energy deposition of non-thermal electron beam in tlare loop with a uniform cross-section through the collisional and reverse current processes is calculated,the heating of soft X-ray plasma by non-thermal electron beam and the energy balance in non-thermal flare model are discussed.

THE TRANSFER OF THE SOLAR ANGULAR MOMENTUM TO THE INTERPLANETARY FIELD BY MEANS OF THE COROAL EXPANSION

Li Zhong-yuan, Cheng Zong-yi, Mo Guo-biao

1992, 12(2): 89-94. doi: 10.11728/cjss1992.02.089

Abstract(2406) PDF 539KB(958)

Abstract:
In the paper,the feature of angular momentum in the coronal expansion is discussed.According to the calculation of data on the Type-I cometary tails,the tangential component of coronal expansion is verified;not only it has a stochastic change,but also it has a confirmed value (9.8km/s).Since the solar evolution reached to the main sequence stage,the sun lost the 80% of its angular momentum,thus the angular velocity of its rotation is reducing by the power index law.

AN EXPLANATION TO THE ELECTRON ENERGY SPECTRA OF SOLAR PURE ELECTRON EVENTS AND PROTON-ELECTRON EVENTS

Zeng Hai-sheng, Huang Yong-nian

1992, 12(2): 95-101. doi: 10.11728/cjss1992.02.095

Abstract(2373) PDF 642KB(851)

Abstract:
The plasma wake fields (PWF) excited in background plasma by solar flare electrons during their coronal propagation are calculated and an effect PWF is analysed in this paper.It is shown that the PWF excited by high-energy solar flare electrons could accelerate low-energy flare electrons and increase their energies by tens or hundreds keV,and,due to this acceleration,the flare electrons’ energy spectrum below about 100 keV could be softened.Considering the PWF effect and other processes,the paper suggest a model for the evolution of energy spectrum of solar flare electrons from acceleration region at the Sun to about 1 AU.It is concluded that,for a solar pure electron event,for which the PWF effect is weak,the electron energy spectrum fits to a double power law,and for a proton-electron event,the PWF effect is strong and the spectrum exhibits a single power law.

A STUDY OF THE IONOSPHERIC DYNAMO BY USING EMPIRICAL MODEL PARAMETERS

Shen Chang-shou, Li Qing, Jiao Wei-xin, Zi Min-yun

1992, 12(2): 102-110. doi: 10.11728/cjss1992.02.102

Abstract(2283) PDF 805KB(1197)

Abstract:
The empirical parameters of MSIS-86 and IRI-86 are used to deduce the three dimensional distribution of ionospheric conductivity and thermospheric wind system.Furthermore,the distribution and variation of the electrostatic potential and layer ionospheric current density at the Northern Hemisphere are calculated by the dynamo theory.The work combines the theoritical research of the ionosphere and thermosphere and the parameters of empirical model based on vast amount of data.The thermospheric wind system,height-integrated conductivity,electrostatic potential and ionospheric current density are compared with observed data and the results deduced from model calculations.There is a good agreement between them.The general significance of the method engaged is discussed too.

EFFECTS OF SOLAR ACTIVITY ON EUV ABSORPTION PROCESSES IN THE UPPER ATMOSPHERE

Chen Yao-wu, Xu Xiu-juan, R. J. Hung

1992, 12(2): 111-117. doi: 10.11728/cjss1992.02.111

Abstract(2298) PDF 501KB(1310)

Abstract:
Using a set of aeronomical parameters,such as absorption cross sections for the dominant thermospheric constituents,EUV flux data from the Atmosphere Explorer Satellites and Hedin’s MSIS-87 neutral thermospheric model,the variations of penetration heights of solar EUV radiation with maximum and minimum solar activities are numerically calculated.For transmit-tance being l/e and 0.1/100,the variations of panetration height of EUV radiation in wavelength range 50-1050 A divided in 37 wavebands are also obtained.The results indicate the penetration heights are obviously controlled by solar activities,and the larger the transmittan-ce is,the closer the correlative relation of penetration height with solar activity is.At the solar zenith angles near normal astronomical sunset,the solar activity leads to increasing the penetration heights on one hand,and to decreasing the Chapman’s function,which reduces the penetration height on the other.These effects could physically explain some ionospheric phenomena observed at local sunset.

SEASONAL VARIATIONS OF S_q(Y) AND FIELD-ALIGNED CURRENTS

Gao Yu-fen

1992, 12(2): 118-122. doi: 10.11728/cjss1992.02.118

Abstract(2207) PDF 456KB(770)

Abstract:
The seasonal variations of East component S_q(Y) observed by the geomagnetic observatory chain in the eastern part of China are analysed.It is found that some of field-aligned currents driven by ionospheric dynamo exist between south-north hemispheres in both winter and summer morning sectors.The direction of the currents is from summer hemisphere to winter hemisphere.It is possible that some reverse currents exist in the afternoon sector.

SCALAR AND VECTOR MAGNETIC ANOMALY MAPS FOR CHINA DERIVED FROM MAGSAT DATA

An Zheng-chang, Xu Yuan-fang, Wang Yue-hua, D. R. Barraclough, D. J. Kerridge

1992, 12(2): 123-128. doi: 10.11728/cjss1992.02.123

Abstract(2514) PDF 594KB(1413)

Abstract:
The Magsat Investigator-B magnetic tapes are the source of data for this study.The lati-tuhe and longitude ranges of data are from 10°N to 60°N and 70°E to 140°E.In order to get the crustal anomaly field,the main field,magnetospheric,ionospheric and induction fields from the Magsat data must be subtracted.The GSFC (12/83) model is used to correct the internal field,external field and induction field.In order to improve pass to pass consistency,the 2nd-order polynomial in latitude is used to fit the crustal anomaly field for each pass,and subtract the fitted values from the crustal anomaly field to get the final crustal anomaly field.The region studied is divided into cells,the size of each cell is one degree in latitude and longitude.The value of the anomaly field at the center of each cell is taken as the mean values of the data falling into the cell.Based on hte grid point values,the contour maps are produced.They include: 1.The X,Y,Z and F anomaly maps derived from dawn data only;2.The X,Y,Z and F anomaly maps derived from dusk data only;3.The X,Y,Z and F anomaly maps derived using dawn and dusk data combined.The contour interval is 2nT.It is considered that the consistency between the dawn and dusk maps is good.The satellite magnetic anomalies in and near China are between-10nT and 10nT.The magnetic anomalies show good correlation with the regional tectonic features of China: Pre-Cam-brian cratons such as Tarim,Yangtze and Sontliao Cratons are positive anomaly areas.The Tibet plateau is negative anomalp area.The satellite anomalies represent the lateral variations in the magnetization of the lowe crust.

REE AND OTHER TRACE ELEMENT CHEMISTRY OF CaS IN QINGZHEN CHONDRITE (EH3) AND THEIR ORIGIN IMPLICATIONS

Chen Yong-heng, Wang Dao-de, E. Pernicka

1992, 12(2): 129-138. doi: 10.11728/cjss1992.02.129

Abstract(3757) PDF 952KB(1435)

Abstract:
INAA of 14 single oldhamite grains extracted from the Qingzhen chondrite (EH3) for refractory (La,Ce,Sm,Eu,Yb,Lu,Ca,Sc,Hf,Th),volatile (Na,Cr,Zn,Se,Br etc.) and siderophile elements (Fe,Ni,Co,Ir,Au,As) reveals that oldhamite is highly enriched in refractory elements,acting as the principal carrier of REE and contains about 80% of all REE in the bulk rock of the Qingzhen enstatite chondrite.Furthermore,LREE has larger enrichment relative to HREE in the Qingzhen oldhamite.In general,the oldhamite form metal-sulfide as-sembleges is more enriched in REE than that from the matrix,i.e.the earlier the oldhamite grains condensed,the more they are enriched in REE.Meanwhile,it is also enriched in volatile elements such as Se,Br etc.In terms of the trace element distribution of the Qingzhen oldhamite it is a high-temperature condensate from the nebula with the solar composition and its condensate origin are suggested.

BEHAVIOR OF THE IONOSPHERIC SLAB THICKNESS OVER CHINESE MID-LATITUDE REGION FOR A HALF SOLAR CYCLE

Liu Xuan-mou

1992, 12(2): 139-145. doi: 10.11728/cjss1992.02.139

Abstract(2099) PDF 578KB(929)

Abstract:
This paper deals with the variations in equivalent slab thickness of the ionosphere over Chinese mid-latitude region for a half solar cycle (1981-1985) using satellite ETS-2 radio beacon observations at Xinxiang (400km subionospheric point: 32.4°N,115.6°E) and Chongqing (400km subionospheric point;27.2°N,108.7°E).The contours and three-dimensional plots for diurnal and seasonal variations of slab thickness are obtained.The harmonic components of diurnal changes in slab thickness are given by Fourier analysis.By the method of linear regressions,a weakly linear dependence of slab thickness with 12 month running mean values of sun-spot number is also obtained.At the same time,the existence of a predawn peak in slab thickness around 0400 to 0700 LT is noted,and the mechanism causing the predawn peak in slab thickness is briefly discussed.

ANALYSIS OF THE IONOSPHERIC SCINTILLATION SPECTRA

Zhen Wei-min, Liu Rui-yuan

1992, 12(2): 146-152. doi: 10.11728/cjss1992.02.146

Abstract(2551) PDF 526KB(1106)

Abstract:
Theoretical formula of scintillation intensity temporal frequency spectrum is presented under oblique incidence and anisotropic irregularity conditions.The theoretical results show that the low-frequency part of spectra are controlled by propagation geometry when irregularities are anisotropic.The propagation angle is thought to be a important factor.Finally,the theory is applied to interpret the VHP signal scintillation data received from the ETS-II at Xinxiang,Wuchang the Guangzhou and the theory correctly predicts the low frequency spectral shapes.

COMPARISON OF THE ASIA OCEANIA REGION F₂ LAYER PREDICTION WITH THE CCIR METHOD

Dai Kai-liang, Lou Fa-gang, Quan Kun-hai, Liu Rui-yuan

1992, 12(2): 153-156. doi: 10.11728/cjss1992.02.153

Abstract(2283) PDF 367KB(1049)

Abstract:
f₀F₂ and M(3000)F₂ calculated using CCIR maps,which is adopted by the International Reference Ionosphere,and that calculated using the Asia Oceania Region (AOR) F₂ Layer Prediction Method are compared with data observed in the 21st solar activity cycle in China.It is noticed that the AOR method gives much more accurate prediction in China,therefore it is suggested that the AOR F₂ layer prediction method should be adopted in the future in "The Reference Ionosphere of China".

SOLAR PROTON EVENTS OBSERVED BY "FENGYUN 1" (FY-1) METEOROLOGICAL SATELLITE

Ye Zong-hai, Chen Gui-fu, Zhu Guang-wu, Shen Si-zhong, Lian Jin-bao, Haung Hong-jin

1992, 12(2): 157-160. doi: 10.11728/cjss1992.02.157

Abstract(2645) PDF 413KB(679)

Abstract:
This paper analyses the solar proton events observed by the cosmic ray composition detector on board the Chinese "Fengyun 1" (FY-1) meteorological satellite.They include the events on Sept.4,1990 and on Feb.l and 2,1991 especially the later events are observed by the Rio-meter at the antarctic Zhong Shang station and by the superneutron monitor at Beijing Station.This shows that the events include the solar protons with very high energy and have very wide energy spectrum.Besides solar protons,a particles,carbon,nitrogen,oxygen and iron particles are also observed at the same time.It is the first time in China that the solar proton events roton event,Solar flare