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Improved method to derive equivalent current systems from global MHD simulations

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Science China Earth Sciences 2014年第1期57卷 167-173页

作者： ZHANG JiaoJiao WANG Chi tang binbin State Key Laboratory of Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences University of Chinese Academy of Sciences

Derivation of equivalent current systems(ECS)from a global magnetospheric magnetohydrodynamics(MHD)model is very useful in studying magnetosphere-ionosphere coupling,ground induction effects,and space weather *** this study we introduce an improved method to derive the ECS from a global MHD model,which takes account of the obliqueness of the magnetic field *** comparing the ECS derived from this improved method and the previous method,we find that the main characteristics of the ECS derived from the two methods are generally consistent with each other,but the eastward-westward component of the geomagnetic perturbation calculated from the ECS derived from the improved method is much stronger than that from the previous *** then compare the geomagnetic perturbation as a function of the interplanetary magnetic field(IMF)clock angle calculated from the ECS derived from both methods with the *** comparison indicates that the improved method can improve the performance of the ***,it is found that the incomplete counterbalance of the geomagnetic effect produced by the ionospheric poloidal current and field-aligned current(FAC)contributes to most of the eastward-westward component of geomagnetic perturbation.

关键词： equivalent current systems global MHD model improved method

Invariant Modulation of IMF Clock Angle on the Solar Wind Energy Input into the Magnetosphere

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空间科学学报 2015年第6期35卷 673-678页

作者： HAN Jinpeng LI Hui tang binbin WANG Chi State Key Laboratory of Space Weather National Space Science CenterChinese Academy of Sciences College of Earth Science University of the Chinese Academy of Sciences Research and Development Center China Academy of Launch Vehicle Technology

By use of the global PPMLR Magnetohydrodynamics(MHD) model,a serial of quasisteady-state numerical simulations were conducted to examine the modulation property of the interplanetary magnetic field clock angle θ on the solar wind energy input into the *** the simulations can be divided into seven groups according to different criteria of solar wind *** each group,37 numerical examples are analyzed,with the clock angle varying from 0° to 360° with an interval of 10°,keeping the other solar wind parameters(such as the solar wind number density,velocity,and the magnetic field magnitude) *** expected,the solar wind energy input into the magnetosphere is modulated by the IMF clock *** axisymmetrical bell-shaped curve peaks at the clock angle of 180°.However,the modulation effect remains invariant with varying other solar wind *** function form of such an invariant modulation is found to be sin(0/2)^(2.70) + 0.25.

关键词： MHD simulation Clock angle Energy input Energy cou

Determination of the Kelvin-Helmholtz Wave Parameters on the Magnetopause in Single-spacecraft Observations

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空间科学学报 2015年第4期35卷 403-408页

作者： LIN Dong WANG Chi LI Wenya tang binbin State Key Laboratory of Space Weather Center for Space Science and Applied ResearchChinese Academy of Sciences University of Chinese Academy of Sciences

Kelvin-Helmholtz(K-H) waves are formed from the triggering of the K-H instability on the magnetopause,which is a candidate mechanism for solar wind entry into the magnetosphere,especially under northward interplanetary magnetic field *** this study,a K-H wave event was identified from the observation of probe B of the Time History of Events and Macroscale Interactions during Substorms(THEMIS) mission on 15 May 2008.A new method to determine the wave parameters of the K-H waves in single-spacecraft observations is *** dominant wave period is determined by three kinds of spectrograms for three key parameters,namely the ion density,the ion temperature,and the z component of magnetic *** phase velocity is estimated by calculating the center-of-mass velocity of the detected K-H vortex *** approximation is validated by comparison with other alternative *** method to determine the wave parameters is a first step to further study K-H wave properties and their relationship with interplanetary conditions.

关键词： Kelvin-Helmholtz waves Magnetopause Single-spacecr

Magnetohydrodynamics (MHD) numerical simulations on the interaction of the solar wind with the magnetosphere: A review

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Science China Earth Sciences 2013年第7期56卷 1141-1157页

作者： WANG Chi GUO XiaoCheng PENG Zhong tang binbin SUN TianRan LI WenYa HU YouQiu State Key Laboratory of Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences School of Earth and Space Sciences University of Science and Technology of China

The magnetosphere is the outermost layer of the geospace, and the interaction of the solar wind with the magnetosphere is the key element of the space weather cause-and-effect chain process from the Sun to Earth, which is one of the most challenging scientific problems in the geospace weather study. The nonlinearity, multiple component, and time-dependent nature of the geospace make it very difficult to describe the physical process in geospace using traditional analytic analysis approach. Numerical simulations, a new research tool developed in recent decades, have a deep impact on the theory and application of the geospace. MHD simulations started at the end of the 1970s, and the initial study was limited to two-dimensional (2D) cases. Due to the intrinsic three-dimensional (3D) characteristics of the geospace, 3D MHD simulations emerged in the 1980s, in an attempt to model the large-scale structures and fundamental physical processes in the magnetosphere. They started to combine with the space exploration missions in the 1990s and make comparisons with observations. Physics-based space weather forecast models started to be developed in the 21st century. Currently only a few space-power countries such as USA and Japan have developed 3D magnetospheric MHD models. With the rapid advance of space science in China, we have developed a new global MHD model, namely PPMLR-MHD, which has high order spatial accuracy and low numerical dissipation. In this review, we will briefly introduce the global 3D MHD modeling, especially the PPMLR-MHD code, and summarize our recent work based on the PPMLR-MHD model, with an emphasis on the interaction of interplanetary shocks with the magnetosphere, large-scale current systems, reconnection voltage and transpolar potential drop, and Kelvin-Helmholtz (K-H) instability at the magnetopause.

关键词： solar wind magnetosphere MHD simulations

Modeling the Jovian magnetosphere under an antiparallel interplanetary magnetic field from a global MHD simulation

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Earth and Planetary Physics 2018年第4期2卷 303-309页

作者： YuXian Wang XiaoCheng Guo binbin tang WenYa Li Chi Wang State Key Laboratory of Space Weather National Space Science Center Chinese Academy of Sciences College of Earth and Planetary Sciences University of Chinese Academy of Sciences

We present preliminary results of a new global Magnetohydrodynamics(MHD) simulation model of the Jovian *** model incorporates mass loading from Jupiter's satellite Io, the planet's fast corotation, and electrostatic coupling between its magnetosphere and ionosphere(M-I coupling). The basic configuration of the Jovian magnetosphere including the equatorial plasma flow pattern, the corotation enforcement current system, and the field aligned currents(FACs) in the ionosphere are presented under an antiparallel interplanetary magnetic field(IMF) condition. The simulation model results for equatorial density and pressure profiles are consistent with results from data-based empirical models. It is also found that there are similarities between the FACs distribution in the ionosphere and the observed aurora features, showing the potential application of the simple ionospheric model to the complicated M-I coupling. This model will help deepen our understanding of the global dynamics of the Jovian magnetosphere.

关键词： Jupiter magnetosphere magnetohydrodynamic(MHD)simulation

Proton pitch angle distributions in the Martian induced magnetosphere: A survey of Tianwen-1 Mars Ion and Neutral Particle Analyzer observations

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Earth and Planetary Physics 2023年第5期7卷 533-539页

作者： TaiFeng Jin binbin Ni LingGao Kong AiBing Zhang Lei Li Song Fu Xing Cao WenYa Li binbin tang LiangHai Xie YiTeng Zhang ShuYue Pang XiaoTong Yun HengLe Du FuHao Qiao LiMin Wang JiJie Ma Department of Space Physics School of Electronic InformationWuhan UniversityWuhan 430072China Chinese Academy of Sciences Center for Excellence in Comparative Planetology Hefei 230026China National Space Science Center Chinese Academy of SciencesBeijing 100190China Beijing Key Laboratory of Space Environment Exploration Beijing 100190China Key Laboratory of Science and Technology on Space Environment Situational Awareness Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Space Weather Chinese Academy of SciencesBeijing 100190China

The pitch angle distributions of ions and electrons can be affected by various processes;thus,they can serve as an important indicator of the physical mechanisms driving the dynamics of space *** observations from the Mars Ion and Neutral Particle Analyzer onboard the Tianwen-1 orbiter,we calculated the pitch angle distributions of protons in the Martian induced magnetosphere by using information from the magnetohydrodynamically simulated magnetic field,and we statistically analyzed the spatial occurrence pattern of different types of pitch angle *** though no symmetrical features were seen in the dataset,we found the dominance of the field-aligned distribution type over the energy range from 188 to 6232 *** of the occurrence rate showed the preferential presence of a trapped-like distribution at the lower altitudes of the surveyed nightside *** our results are more or less restricted by the adopted magnetic field,they indicate the complexity of the near-Mars proton pitch angle distributions and infer the possibility of wave–particle interactions in the Martian induced magnetosphere.

关键词： Martian plasma environment ion pitch angle distribution Tianwen-1 Mars Ion and Neutral Particle Analyzer(MINPA)

Deformations at Earth’s dayside magnetopause during quasi-radial IMF conditions:Global kinetic simulations and Soft X-ray Imaging

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Earth and Planetary Physics 2024年第1期8卷 59-69页

作者： ZhongWei Yang RiKu Jarvinen XiaoCheng Guo TianRan Sun Dimitra Koutroumpa George K.Parks Can Huang binbin tang QuanMing Lu Chi Wang State Key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China Finnish Meteorological Institute FI-00101 HelsinkiFinland LATMOS/IPSL CNRSUVSQ UniversitéParis-SaclaySorbonne UniversitéGuyancourt78280France Space Sciences Laboratory University of CaliforniaBerkeleyCalifornia 94720USA CAS Engineering Laboratory for Deep Resources Equipment and Technology Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029 China Deep Space Exploration Laboratory/School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China

The Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)is a joint mission of the European Space Agency(ESA)and the Chinese Academy of Sciences(CAS).Primary goals are investigating the dynamic response of the Earth's magnetosphere to the solar wind(SW)impact via simultaneous in situ magnetosheath plasma and magnetic field measurements,X-Ray images of the magnetosheath and magnetic cusps,and UV images of global auroral *** deformations associated with magnetosheath high speed jets(HSJs)under a quasi-parallel interplanetary magnetic field condition are studied using a threedimensional(3-D)global hybrid *** X-ray intensity calculated based on both physical quantities of solar wind proton and oxygen ions is *** obtain key findings concerning deformations at the magnetopause:(1)Magnetopause deformations are highly coherent with the magnetosheath HSJs generated at the quasi-parallel region of the bow shock,(2)X-ray intensities estimated using solar wind h+and self-consistentO7+ions are consistent with each other,(3)Visual spacecraft are employed to check the discrimination ability for capturing magnetopause deformations on Lunar and polar orbits,*** SMILE spacecraft on the polar orbit could be expected to provide opportunities for capturing the global geometry of the magnetopause in the equatorial plane.A striking point is that SMILE has the potential to capture small-scale magnetopause deformations and magnetosheath transients,such as HSJs,at medium altitudes on its *** results also demonstrate that a lunar based imager(e.g.,Lunar Environment heliospheric X-ray Imager,LEXI)is expected to observe a localized brightening of the magnetosheath during HSJ events in the meridian *** preliminary results might contribute to the pre-studies for the SMILE and LEXI missions by providing qualitative and quantitative soft X-ray estimates of dayside kinetic processes.

关键词： collisionless shock SMILE mission foreshock

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检察机关合规不起诉裁量权限制的三种模式

法制与社会发展 2022年第1期28卷 40-58页

作者：唐彬彬中国人民公安大学法学院中国人民公安大学企业合规与社会治理研究院

作为一种以合规激励为核心的合作性司法模式,合规不起诉制度是起诉便宜原则的又一适用场域。如何明确和限制检察机关的自由裁量权,是在探索合规不起诉制度时应该关注的问题。从比较法的视野来看,美国的内部控制模式和英国的司法监督模... 详细信息

作为一种以合规激励为核心的合作性司法模式,合规不起诉制度是起诉便宜原则的又一适用场域。如何明确和限制检察机关的自由裁量权,是在探索合规不起诉制度时应该关注的问题。从比较法的视野来看,美国的内部控制模式和英国的司法监督模式是目前限制合规不起诉裁量权的两种主要代表模式。内部控制模式以美国司法部的内部文件的约束为主要手段,侧重发挥合规不起诉制度的犯罪预防和社会治理功能。司法监督模式以法官的司法审查为主要手段,关注对合规不起诉裁量权的实际控制问题。我国对合规不起诉裁量权的限制采用的是双重控制模式,即以保护民营企业这一基本原则与合规不起诉制度的适用条件为内部约束,以第三方监督评估机制与合规听证为外部监督机制。作为主管部门的最高人民检察院,可以通过制定司法解释或者规范性文件,总结实践经验,进一步细化合规不起诉适用对象的遴选条件,明确有效合规的标准,促进程序公开透明。

关键词：合规不起诉裁量权内部控制模式司法监督模式双重控制模式

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数据本地化法律规制的反思与完善

情报杂志 2022年第5期41卷 162-168,197页

作者：唐彬彬中国人民公安大学法学院北京100038

[研究目的]归纳、分析导致我国数据本地化立法失灵的多重因素,在发展与安全之间,寻求我国跨境数据流动的妥善规制方案。[研究方法]从数据本地化的理论基础与立法路径出发,收集、整理数据安全保护的相关立法与案例,系统地论述我国数据安... 详细信息

[研究目的]归纳、分析导致我国数据本地化立法失灵的多重因素,在发展与安全之间,寻求我国跨境数据流动的妥善规制方案。[研究方法]从数据本地化的理论基础与立法路径出发,收集、整理数据安全保护的相关立法与案例,系统地论述我国数据安全存在的威胁,并分析可能的解决途径。[研究结论]我国仅靠单边立法与技术革新,难以完成数据本地化的重任。应当以提升网络综合能力为起点,多种角度完善数据治理机制:完善数据安全评估制度;通过反垄断避免产生超级数据企业,防止数据风险扩大;加强企业的数据合规体系建设。

关键词：数据数据本地化跨境数据流动数据主权数据安全

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