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Chinese Science Bulletin 2001年第1期46卷 39-42页

作者： Jingqun Li fengsi wei Laboratory of Numerical Study of Heliospheric Physics Center for Space Science and Applied Research Chinese Academy of Sciences Beijing China

The conventional nonreflecting projective charac teristic boundary condition for MHD equations is improved in order to remove spurious oscillations caused by the presence of zero point of the components of magnetic field. The improved boundary condition is easier to be implemented in programming, and its application to the simulation of asymmetric corona can give us stable coronal static structures.

关键词： corona characteristics boundary condition.

Numerical study of magnetic reconnection process near interplanetary current sheet

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Chinese Science Bulletin 2001年第2期46卷 111-117页

作者： fengsi wei Qiang Hu Xueshang Feng Ctr Space Sci & Appl Res Lab Space Weather Beijing 100080 Peoples R China

The third order accurate upwind compact difference scheme has been applied to the numerical study of the magnetic reconnection process possibly occurring near the interplanetary current sheet, under the framework of the two-dimensional compressible magnetohydrodynamics (MHD). Our results here show that the driven reconnection near the current sheet can occur within 10-30 min for the interplanetary high magnetic Reynolds number, RM =2 000-10 000, the stable magnetic reconnection structure can be formed in hour-order of magnitude, and there are some basic properties such as the multiple X-line reconnections, vortical velocity structures, filament current systems, splitting and collapse of the high-density plasma bulk. These results are helpful in understanding and identifying the magnetic reconnection phenomena near the interplanetary current sheets.

关键词： interplanetary space current sheet magnetic recon-nection numerical simulation.

Magnetic reconnection structures in the boundary layer of an interplanetary magnetic cloud

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Science China(Technological Sciences) 2004年第1期47卷 6-14页

作者： wei fengsi LIU Rui FENG Xueshang ZHONG Dingkun YANG Fang Key Laboratory for Space Weather Chinese Academy of Sciences Beijing 100080 China Key Laboratory for Space Weather Chinese Academy of Sciences Beijing 100080 China Key Laboratory for Space Weather Chinese Academy of Sciences Beijing 100080 China Key Laboratory for Space Weather Chinese Academy of Sciences Beijing 100080 China Key Laboratory for Space Weather Chinese Academy of Sciences Beijing 100080 China

An interplanetary magnetic diffusion region was detected by WIND during 0735-0850 UT on May 15, 1997 when the front boundary layer of a magnetic cloud passed through the spacecraft about 190 earth radii upstream of the earth. The main signals of magnetic reconnection processes are: (i) Flow reversal was detected at about 0810 UT. The counter-streaming flows have the speeds of about 65 and 41 km/s, respectively, with an angle of about 140 degree between them. (ii) Hall magnetic field was detected. The Hall fields ?By and +By, perpendicular to the X-Z plane, with their magnitude up to ～7.0 nT, are superposed upon a guide field about 12 nT. (iii) Alfvenic fluctuations are obviously intensified inside the reconnection region; at the front boundary of the reconnection region, a slow-mode-like discontinuity was detected. (iv) Ions are heated intensively inside the reconnection region, with their temperature three times higher than that ahead of the boundary layer; electrons are also heated, with a little enhancement in their temperature. The above observations indicate that magnetic reconnection processes could take place in interplanetary space. Keywords solar wind - interplanetary magnetic clouds - magnetic reconnection

关键词： solar wind, interplanetary magnetic clouds, magnetic reconnection.

WIND observations of plasma waves inside the magnetic cloud boundary layers

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Chinese Science Bulletin 2005年第18期50卷 2051-2056页

作者： wei fengsi ZHONG Dingkun FENG Xueshang YANG Fang LIU Rui SIGMA Weather Group Laboratory for Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100080 China Graduate School Chinese Academy of Sciences Beijing 100049 China

Based on the WIND observational data for the plasma waves from thermal noise receptor (TNR) working on the frequency 4―256 kHz and the solar wind and the magnetic fields, we analyze the plasma wave activities in the 60 magnetic cloud’s boundary layers (BLs) and find that there are often various plasma wave activities in the BLs, which are different from those in the adjacent solar wind (SW) and the magnetic clouds (MC). The basic characteris-tics are that: (1) the enhancement of the Langmuir wave near the electronic plasma frequency (fpe) is a dominant wave ac-tivity, which occupies 75% investigated samples; (2) the events enhanced both in the langmuir and ion acustic (f < fpe) waves are about 60% of investigated samples; (3) broadband, continuous enhancement events in the plasma wave activities were observed in the whole frequency band of TNR, and about 30% of the 60 samples, however, were not observed in the SW and the MC investigated events; (4) although the ratio of the temperatures between the electon and proton, Te/Tp≤1, the ion caustic wave enhancement activities are still often observed in the BLs, which makes it difficult to ex- plain them by the traditional plasma theory. New results reported in this paper further show that the magnetic cloud’s BL is an important dynamic structure, which could provide useful diagnosis for understanding the cloud’s BL physics and could expand a space developing space plasma wave theory.

关键词：边界层等离子体波磁场 Langmuir波频率分布

A Prediction Method for △f_0F_(2min) of a Single Station From Interplanetary Parameters Based on Statistical Study

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空间科学学报 2012年第3期32卷 312-320页

作者： LI Zheng wei fengsi FENG Xueshang GUO Jianpeng XU Xiaojun State Key Laboratory of Space Weather Center for Space Science and Applied ResearchChinese Academy of SciencesBeijing 100190 Graduate University of the Chinese Academy of Sciences Beijing 100049

Using 86 CME-interplanetary shock events,the correlation between the peak values of (a) the solar wind parameters(B_z,E_y,P_(dyn)) and the geomagnetic indices(SYM-H,ASY-H,Kp), (b) the coupling functions(Borovsky,Akasofu,Newell) and the geomagnetic indices,(c) the solar wind parameters/coupling functions/geomagnetic indices and the ionospheric parameter(Δf_0F_(2min)), are *** statistical results show that in group(a),B_(z min) and SYM-H_(min) have the best correlation,that in group(b),the best correlation is between the peak values of Akasofu function (A_(min)) and SYM-H_(min),and that in group(c),the best correlation is between K_(pmax) andΔf_0F_(2min). Based on the statistical results,a method for predicting f_0F_2 of a single station is attempted to be set *** input is modified B_(z min) and the outputs are SYM-H_(min) andΔf_0F_(2min).Then 25 CME-IPS events that caused geomagnetic storms in 1998 and 2009 are used to check the prediction method. The results show that our method can be used to predict SYM-H_(min) andΔf_0F_(2min).

关键词：行星际激波统计预报方法单站最小距离基础地磁指数电离层参数

A BRIEF INTRODUCTION TO MERIDIAN PROJECT

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空间科学学报 2002年第Z1期22卷 35-38页

作者： wei fengsi XIAO Zuo WU Jian GUO Jianshan FENG Xueshang Center for Space Science and Applied Research The Chinese Academy of Sciences Beijing 100080 P.R. China Department of Geophysics Peking University P.R. China Institute of Radio Propagation Ministry of Information Industry P.R.China Center for Space Science and Applied Research The Chinese Academy of Sciences Beijing 100080 P.R. China Center for Space Science and Applied Research The Chinese Academy of Sciences Beijing 100080 P.R. China

　　Early in 1994, sponsored by Chinese Academy of Sciences (CAS) and then the State Science and Technology Commission of China (SSTC, now Ministry of Sci ence and Technology), Chinese space scientists (including scientists from Taiwan) gathered together to discuss issues on the development of space physics researches in China. Following it, several special seminars were held to continue the discus sion which finally led to a proposal to CAS and SSTC for establishing a station chain along the 120°E to monitor the space environment. This proposal was care fully reviewed and thoroughly evaluated by many leading scientists in the com munity and then listed in the State Plan of Chinese Central Government in June 1997. The project then has been formally called as "Meridian Chain of Compre hensive Ground-Based Space Environment Monitors in the Eastern Hemisphere" "Meridian Project". After several years of preparations the project has been par tially initiated with the efforts devoted by institutes and universities involved.……

关键词： space environment Science and Technology

A CLASS OF TWO-STEP TVD MACCORMACK TYPE NUMERICAL SCHEME FOR MHD EQUATIONS

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空间科学学报 2003年第6期23卷 401-412页

作者： FENG Xueshang wei fengsi ZHONG Dingkun(Center for Space Science and Applied Research, The Chinese Academy of Sciences, Beijing 100080) Center for Space Science and Applied Research The Chinese Academy of Sciences 北京 100080

In this paper, a new numerical scheme of Total Variation Diminishing (TVD) MacCormack type for MagnetoHydroDynamic (MHD) equations is proposed by taking into account of the characteristics such as convergence, stability, resolution. This new scheme is established by solving the MHD equations with a TVD modified MacCormack scheme for the purpose of developing a scheme of quick convergence as well as of TVD property. To show the validation, simplicity and practicability of the scheme for modelling MHD problems, a self-similar Cauchy problem with the discontinuous initial data consisting of constant states, and the collision of two fast MHD shocks, and two-dimensional Orszag and Tang's MHD vortex problem are discussed with the numerical results conforming to the existing results obtained by the Roe type TVD, the high-order Godunov scheme,and weighted Essentially Non-Oscillatory (WENO) scheme. The numerical tests show that this two-step TVD MacCormack numerical scheme for MHD system is of robust operation in the presence of very strong waves, thin shock fronts, thin contact and slip surface discontinuities.

关键词：磁液体力学方程两步TVD-MacCormack图解法收敛性稳定性数值模拟

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空间天气学

地球物理学进展 1999年第S1期14卷 1-7页

作者：魏奉思中国科学院空间科学与应用研究中心<日球物理数值研究开放实验室> 北京100080

本文仅对空间天气学的提出和新特点以及空间天气过程研究的基础———三种全球结构及其相互作用问题作粗略介绍

关键词：空间灾害空间天气学全球结构

STATISTIC STUDY ON ASYMMETRIC PROPAGATION OF FLARE-ASSOCIATED INTERPLANETARY SHOCK WAVES

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Science in China,Ser.A 1988年第4期 451-460页

作者：魏奉思 Institute of Space Physics Academia Sinica Beiiing

On the basis of the comprehensive studies of solar flare-associated geophysical effects (geomagnetic disturbances and the Forbush decreases of cosmic rays), multi-spacecraft observations of solar wind and interplanetary scintillation (IPS) observations, we have furthered our knowledge of the flare-shock wave propagation in the interplanetary space. The main results are that the flare-shock wave is usually an asymmetric propagation related to the flare normal, the direction of the fastest propagation velocity in longitudes tends to deflect towards the interplanetary spiral magnetic field and that in latitudes approaches heliospheric, current sheet, the dynamic parameters (V, P, N, T, β, etc.) and the. shock wave energy. E, are higher in the southeast than in the northwest of the flare shock wave, and conversely, the magnetic field is weaker in the southeast than in the northwest. Based on the results, we proposed a 3-dimensional asymmetrical model of flare-shock wave propagationst. This model is consist

关键词： STATISTIC STUDY ON ASYMMETRIC PROPAGATION OF FLARE-ASSOCIATED INTERPLANETARY SHOCK WAVES

FLARE-ASSOCIATED SHOCK WAVE PROPAGATION AT LARGE HELIOCENTRICAL DISTANCES

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Chinese Science Bulletin 1985年第3期30卷 361-364页

作者：魏奉思 Institute of Space Physics Academia Sinica Beijingt present the study of the interplanetary shock wave concentrates mostly within 1 AU region from the sun and for large heliocentrical distances (>2-3 AU)the study of shock wave propagation still remains in the experimental stage. According to large amounts of space observations the interplanetary space can be divided into three re-

At present the study of the interplanetary shock wave concentrates mostly within 1 AU region from the sun, and for large heliocentrical distances (>2—3 AU)the study of shock wave propagation still remains in the experimental stage. According to large amounts of space observations, the interplanetary space can be divided into three re-

关键词： mostly motive helio WAVE observational esses mentioned burst exert transit