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Mercury's ring current and Mercury's magnetic storms

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Science China(Technological Sciences) 2022年第5期65卷 1210-1212页

作者： FU SuiYan zong qiugang Institute of Space Physics and Applied Technology Peking UniversityBeijing100871China

A magnetic storm is a temporal magnetic disturbance caused by solar wind interaction with the Earth’s magnetosphere.A geomagnetic storm on the scale of the year 1859 event[1] would cause trillions of dollars loss to ... 详细信息

关键词： storm Earth Mercury

Analysis of the internal charging data in medium earth orbit with numerical simulation and ground experiment

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Science China(Technological Sciences) 2022年第4期65卷 977-986页

作者： SONG SiYu CHEN HongFei YU XiangQian ZOU Hong zong qiugang CHEN Ao SHI WeiHong YE YuGuang Institute of Space Physics and Applied Technology School of Earth and Space SciencesPeking UniversityBeijing 100871China

The deep dielectric charging effect monitor(DDCEM)has been designed to study the internal charging effect by measuring the charging currents and potentials inside the *** is equipped on three Chinese navigation satellites in a circular medium earth orbit(MEO)with 22000 km average height and 55°*** simulation based on the Geant4-RIC method was used to evaluate the data of *** data during May to November 2019 on one of the three satellites show that the charging currents of DDCEM were negatively enhanced when the satellite moved into the outer radiation *** currents reached the negative maximum during a significant electron enhancement in September *** currents were also detected besides negative currents that were caused by the deposition of electrons in the *** causation of positive currents in the space environment may be that the low-energy electrons cannot penetrate the satellite skin and make it charging to negative potential,the reference ground of DDCEM that is connected to the satellite skin drops below zero by the low-energy electrons so that the output currents turn to *** experiment was used to simulate the causation of positive currents and the result verified our theory.

关键词： deep dielectric charging effect monitor internal charging effect charging currents and potentials medium earth orbit space environment

Magnetic storms in Mercury's magnetosphere

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Science China(Technological Sciences) 2022年第6期65卷 1427-1432页

作者： zong qiugang ZHAO JiuTong LIU JianJun FU SuiYan SUN WeiJie ZHANG Hui LE Guan RANKIN Robert WEI Yong Institute of Space Physics and Applied Technology Peking UniversityBeijing 100871 China Polar Research Institute of China Shanghai 2000136China Department of Climate and Space Sciences and Engineering University of MichiganAnn Arbor 48109USA Geophysical Institute University of Alaska FairbanksFairbanks 99775USA ITM Laboratory Heliophysics Science DivisionNASA Goddard Space Flight CenterGreenbelt 20771USA Department of Physics University of AlbertaEdmonton T6G2R3Canada Institute of Geology and Geophysics Chinese Academy of SciencesBeijing 100029China

We present evidence of geomagnetic storms in Mercury’s magnetosphere based on MESSENGER magnetic field observations made just before the probe impacted the *** findings answer the question of whether geomagnetic storms can occur in other planetary *** interaction of the solar wind with Mercury’s magnetosphere is known to involve flux transfer events in the dayside magnetosphere,plasmoids and flux ropes in the magnetotail,and substorm-like processes,all of which occur morphologically similar to Earth but with significant *** significantly weaker magnetic field,smaller magnetosphere,and much faster timescale of processes around Mercury,when compared with Earth,enable charged particles to escape its magnetosphere more efficiently through magnetopause shadowing and direct bombard of the *** analysis of MESSENGER’s data during a coronal mass ejection(CME)proves that,despite these substantial differences,a bifurcated ring current can form in Mercury’s magnetosphere that initiates magnetic storms under strong solar wind driving.

关键词： magnetic storm Mercury magnetosphere ring current

A cross-type imaging electron spectrometer

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Science China(Technological Sciences) 2023年第3期66卷 641-653页

作者： YE YuGuang ZOU Hong WANG YongFu QIN JunFeng SHI WeiHong ZOU JiQing ZHONG WeiYing zong qiugang FU SuiYan School of Earth and Space Sciences Peking UniversityBeijing 100871China

Energetic electron measurement is of great significance to theoretical space physics research and space weather *** energetic electron detectors must cooperate with a spin-stabilized satellite platform to achieve high angular resolution in pitch angle distribution and three-dimensional(3D)imaging measurement of energetic *** article introduces a cross-type quasi-3D imaging electron spectrometer(IES)based on pinhole imaging technology developed in the *** imager is composed of five imaging units,including a nine-pixel area array Si-PIN detector imaging unit in the middle and four three-pixel linear array Si-PIN detector imaging units placed in a cross-shape around *** combination of five imaging units forms two orthogonal nine-pixel linear array detectors(with a common pixel in the middle).There are four pixels with a view angle of 20°×20°in the 45°oblique directions of the cross-type detection *** are 21 imaging pixels in the entire crosstype sensor head,corresponding to 21 *** multichannel integrated preamplifier ASICs are integrated in the sensor head to realize particle signal readout from 21 *** a back-end electronics system,each pixel can achieve high energy resolution detection of 50–600 keV *** sources and electron accelerators are used to calibrate the cross-type imaging sensor head,and the results demonstrate its good energy and directional detection characteristics(the energy resolution reaches 6.9 keV for the incident 200 keV electron beam).We performed simulations on the imaging sensor head’s ability to measure the electron pitch angle distribution on the three-axis stabilized platform,and the results show that the sensor head can perform quasi-three-dimensional detection of electrons incident within 2πsolid angles on the three-axis stabilized satellite platform,with an average angular resolution of the electron pitch angle distribution of less than 6°.

关键词： energetic electron detection imaging electron spectrometer cross-type sensor head pitch angle distribution

Reconstruction of morningside plasma sheet compressional ULF Pc5 wave

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Science China(Technological Sciences) 2012年第6期55卷 1092-1100页

作者： TIAN AnMin zong qiugang SHI QuanQi Institute of Space Physics andApplied Technology Peking UniversityBeijing 100871China School of Space Science and Physics Shandong UniversityWeihai 264209China

We studied the compressional wave event in Pc5 frequency range observed in the dawn-side magnetic equator on 9 March 1998 by Grad-Shafranov(GS) reconstruction method for the first time. To test the effectiveness of application of GS method on Pc5 compressional wave, we benchmarked our procedure by applying it to a one-dimensional current sheet model first. Excluding the left-hand corners, the average error magnitude was less than 10%. The reconstruction of actual data showed that we obtained the 2-D map of compressional wave without suffering model constraints for the first time. The magnetic filed lines density cyclical changed, and the wavelength was about 2-4 times earth radius. The reconstructed magnetic topology had a shape very similar to the empirical 2-dimensional standing wave model proposed by the former workers. Besides, we also recovered the plasma thermal pressure and current density of the wave quantitatively.

关键词：等离子体片 ULF 挤压纵波测试模型约束 GS方法周期性变化频率范围

Cases and statistical study on Hot Flow Anomalies with Cluster spacecraft data

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Science China(Technological Sciences) 2012年第7期55卷 1402-1418页

作者： WANG Shan zong qiugang ZHANG Hui Institute of Space Physics and Applied Technology Peking UniversityBeijing 100871China Geophysical Institute University of Alaska FairbanksFairbanksAK 99775USA

Hot Flow Anomalies (HFAs) are phenomena that frequently appear in the vicinity of the Earth's bow shock. We have identified 765 HFA events with Cluster spacecraft data from 2003 to 2009. We study the plasma and magnetic field variations during typical HFAs. Then we study the average structure of HFAs using the superposed epoch method during a 200 s time interval, with the HFA onset time as the epoch time. The results show that HFAs can be classified into four classes based on variations of the dynamic pressure over time, namely "-+" (down-up), "+-" (up-down), "M" (up-down-up) and "W" (up-down-up-down-up), where the letters represent similar shapes with the variation trends of the dynamic pressure. Trends of other parameters are highly related to those of the dynamic pressure with obvious characteristics of the classification. Moreover, statistical results suggest that the number of HFA events varies in years. Compared with the speed of solar wind and sunspot number, the number of HFA events in each year has positive correlation with the former, while it has little relation with the latter. The result of this paper will provide data base for further studies on the mechanisms of the formation, the structural evolution and other relative questions of HFAs.

关键词： Cluster 卫星数据热流量统计时间间隔异常动态压力太阳黑子数

In-flight vector magnetometer calibration for FY-3E satellite

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Science China(Technological Sciences) 2023年第6期66卷 1867-1868页

作者： WANG YongFu YU XiangQian zong qiugang XIAO ChiJie LIU Si CHEN HongFei ZOU Hong SHI WeiHong School of Earth and Space Sciences Peking UniversityBeijing 100871China School of Physics Peking UniversityBeijing 100871China School of Physics and Electronic Science Changsha University of Science&TechnologyChangsha 410114China

The FY-3E meteorological satellite was launched by China on July 5,*** orbit of the satellite is sun-synchronous with an orbit altitude 836 km and orbit period 102 *** satellite is equipped with a triaxial anisotropic magnetore-sistance magnetometer to detect ultra-low frequency waves in the *** magnetometer sensor is situated on the satellite *** is approximately 1 m away from the satellite body to reduce the effect of spacecraft fields.

关键词： magnetometer satellite equipped

Test particle simulation on the ion and electron zebra stripes and their time evolution in inner radiation belt

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Science China(Technological Sciences) 2018年第4期61卷 623-632页

作者： WANG YongFu zong qiugang ZHOU XuZhi State Key Laboratory of Nuclear Physics and Technology School of Physics and Fusion Simulation CenterPeking University Institute of Space Physics and Applied Technology Peking University Key Laboratory of Earth and Planetary Physics Chinese Academy of Sciences

During February 15–16, 2014, the energetic electron spectrogram for four successive inner radiation belt crossing show clearly the electron zebra structures and their time evolution which last for about 17 h. Unfortunately, the time of flight(TOF) in RBSPICE measurement is turned off below 3 RE, and the ion measurement is contaminated by electrons. Thus in this study we studied the differences between the ion and electron zebra stripe structures and their time evolution using simple theory and test particle simulation, combining the electron measurement from RBSIPICE onboard Van Allen Probes. Theoretical analysis predicts that the ion zebra stripe structures should lie at a higher energy range than the corresponding electron zebra stripe structures due to that the directions of gradient B drift and corotation E×B drift are the same for electrons while opposite for ions. Test particle simulation with the dipole magnetic field and Volland-Stern electric field model have shown that the ion and electron zebra stripe structures could be produced by the convection electric field penetrating into the inner magnetosphere in this event, with their time evolution determined by total drift velocity that are different for ions and electrons. The predicted differences between the ion and electron zebra stripe structures are partially verified through observation. The ion zebra stripe structures could have potential influence to the ring current.

关键词：电子污染条纹结构粒子模拟离子斑马时间进化测试

Practicable method to identify ferromagnetic objects

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Science China(Technological Sciences) 2022年第12期65卷 3079-3081页

作者： YU XiangQian WANG YongFu XIAO ChiJie LIU Si zong qiugang CHEN HongFei ZOU Hong SHI WeiHong CHEN Ao School of Earth and Space Sciences Peking UniversityBeijing 100871China School of Physics Peking UniversityBeijing 100871China School of Physics and Electronic Science Changsha University of Science&TechnologyChangsha 410114China

Ferromagnetic objects are ubiquitous in the world and the identification of ferromagnetic objects is important in many *** the position and magnetic parameters of the ferromagnetic object from its magnetic signature i... 详细信息

关键词： ferromagnetic signature mining