This is a concise review of physics of the substorm in the magnetotail.It consists of two parts. The first part summarizes historical developments in the early days of the space age(1960-1975)when the basic concepts s...This is a concise review of physics of the substorm in the magnetotail.It consists of two parts. The first part summarizes historical developments in the early days of the space age(1960-1975)when the basic concepts such as magnetotail and reconnection were established and the leading model of the substorm was introduced.The second part is an overview of the research conducted in recent years(1995-2010)when very significant advances have been achieved in understanding the substorm physics by virtue of several major satellites missions that addressed the magnetotail physics intensively.展开更多
Magnetic reconnection is one of the most important,dynamic phenomena in the magnetotail in terms of magnetic field line configuration change and energy release.It is believed to occur in the distant magnetotail mainly...Magnetic reconnection is one of the most important,dynamic phenomena in the magnetotail in terms of magnetic field line configuration change and energy release.It is believed to occur in the distant magnetotail mainly during southward interplanetary magnetic field periods and in the near-Earth magnetotail in association with substorms.In the present paper,we discuss several important issues concerning magnetic reconnection in the magnetotail associated with substorms,such as reconnection signatures,location,timing,spatial scale,and behavior,from the macroscopic,observational point of view.展开更多
地球磁层顶频发的开尔文–赫姆霍兹(Kelvin-Helmholtz,K-H)不稳定性在太阳风的物质和能量向地球磁层的输运过程中发挥着重要的作用.研究筛选出2015-2020年中磁尾区域(X≈–60 Re)的磁层顶穿越事件,结合51个中磁尾处的K-H不稳定性事件,...地球磁层顶频发的开尔文–赫姆霍兹(Kelvin-Helmholtz,K-H)不稳定性在太阳风的物质和能量向地球磁层的输运过程中发挥着重要的作用.研究筛选出2015-2020年中磁尾区域(X≈–60 Re)的磁层顶穿越事件,结合51个中磁尾处的K-H不稳定性事件,统计研究了K-H不稳定性在中磁尾磁层顶的晨昏不对称性分布.结果表明,在中磁尾区域,磁层顶晨侧的K-H不稳定性发生率较高.在行星际磁场(Interplanetary Magnetic Field,IMF)北向条件下,发生在磁层顶晨侧的K-H不稳定性事件数量明显超越昏侧;当帕克–螺旋(Parker-Spiral,PS)IMF主导时,昏侧K-H不稳定性事件更多.太阳风的不同参数也会显著影响中磁尾区域磁层顶晨昏两侧的KH涡旋分布.磁尾区域的K-H波动也是导致磁尾等离子体片中不同温度的等离子体分布不对称的原因之一.展开更多
本文基于自己开发的全球三维磁层模型,模拟研究了IMF(Interplanetary Magnetic Field)北向并且By分量较大(时钟角为60°)时磁层顶三维结构及其重联图像.结果发现,IMF By为正时,在北极隙区附近尾-昏侧存在IMF与地磁场之间稳定持续的...本文基于自己开发的全球三维磁层模型,模拟研究了IMF(Interplanetary Magnetic Field)北向并且By分量较大(时钟角为60°)时磁层顶三维结构及其重联图像.结果发现,IMF By为正时,在北极隙区附近尾-昏侧存在IMF与地磁场之间稳定持续的重联现象;参与重联的地球磁场既有闭合磁力线也有开放磁力线;IMF在北极隙区与地球闭合磁力重联后一端与南磁极相连的磁力线在尾向运动时还可能与北尾瓣的开放磁力线重联而重新闭合,这种重联与磁力线循环过程不同于同一条IMF磁力线分别在南北半球与地磁场重联的模型.南极隙区的重联发生在尾-晨侧,其动力学过程与北极隙区情形类似.我们的模拟结果表明,IMF By较大时不可能发生IMF同一条磁力线分别在南北极隙区重联的情形,也不会因此而减少尾瓣的开放磁力线.展开更多
In this paper,the y-component of magnetic field line curvature in the plasma sheet was analyzed,and two kinds of shear structures of the flapping current sheet were found,i.e.symmetric and antisymmetric.The alternatin...In this paper,the y-component of magnetic field line curvature in the plasma sheet was analyzed,and two kinds of shear structures of the flapping current sheet were found,i.e.symmetric and antisymmetric.The alternating bending orientations of the guiding field are exactly corresponding to alternating north-south asymmetries of the bouncing ion population in the sheet center.Those alternating asymmetric plasma sources consequently induce the current sheet flapping motion as a driver.In addition,a substantial particle population with downward motion was observed in the center of a bifurcated current sheet.This population is identified as the quasi-adiabatic particles,and provides a net current opposite to the conventional cross-tail current.展开更多
文摘This is a concise review of physics of the substorm in the magnetotail.It consists of two parts. The first part summarizes historical developments in the early days of the space age(1960-1975)when the basic concepts such as magnetotail and reconnection were established and the leading model of the substorm was introduced.The second part is an overview of the research conducted in recent years(1995-2010)when very significant advances have been achieved in understanding the substorm physics by virtue of several major satellites missions that addressed the magnetotail physics intensively.
基金Supported in part by the Global COE Program of Nagoya University "Quest for Fundamental Principles in the Universe(QFPU)" from JSPS and MEXT of Japan
文摘Magnetic reconnection is one of the most important,dynamic phenomena in the magnetotail in terms of magnetic field line configuration change and energy release.It is believed to occur in the distant magnetotail mainly during southward interplanetary magnetic field periods and in the near-Earth magnetotail in association with substorms.In the present paper,we discuss several important issues concerning magnetic reconnection in the magnetotail associated with substorms,such as reconnection signatures,location,timing,spatial scale,and behavior,from the macroscopic,observational point of view.
文摘地球磁层顶频发的开尔文–赫姆霍兹(Kelvin-Helmholtz,K-H)不稳定性在太阳风的物质和能量向地球磁层的输运过程中发挥着重要的作用.研究筛选出2015-2020年中磁尾区域(X≈–60 Re)的磁层顶穿越事件,结合51个中磁尾处的K-H不稳定性事件,统计研究了K-H不稳定性在中磁尾磁层顶的晨昏不对称性分布.结果表明,在中磁尾区域,磁层顶晨侧的K-H不稳定性发生率较高.在行星际磁场(Interplanetary Magnetic Field,IMF)北向条件下,发生在磁层顶晨侧的K-H不稳定性事件数量明显超越昏侧;当帕克–螺旋(Parker-Spiral,PS)IMF主导时,昏侧K-H不稳定性事件更多.太阳风的不同参数也会显著影响中磁尾区域磁层顶晨昏两侧的KH涡旋分布.磁尾区域的K-H波动也是导致磁尾等离子体片中不同温度的等离子体分布不对称的原因之一.
文摘本文基于自己开发的全球三维磁层模型,模拟研究了IMF(Interplanetary Magnetic Field)北向并且By分量较大(时钟角为60°)时磁层顶三维结构及其重联图像.结果发现,IMF By为正时,在北极隙区附近尾-昏侧存在IMF与地磁场之间稳定持续的重联现象;参与重联的地球磁场既有闭合磁力线也有开放磁力线;IMF在北极隙区与地球闭合磁力重联后一端与南磁极相连的磁力线在尾向运动时还可能与北尾瓣的开放磁力线重联而重新闭合,这种重联与磁力线循环过程不同于同一条IMF磁力线分别在南北半球与地磁场重联的模型.南极隙区的重联发生在尾-晨侧,其动力学过程与北极隙区情形类似.我们的模拟结果表明,IMF By较大时不可能发生IMF同一条磁力线分别在南北极隙区重联的情形,也不会因此而减少尾瓣的开放磁力线.
基金the National Natural Science Foundation of China(41174144,40974098)。
文摘In this paper,the y-component of magnetic field line curvature in the plasma sheet was analyzed,and two kinds of shear structures of the flapping current sheet were found,i.e.symmetric and antisymmetric.The alternating bending orientations of the guiding field are exactly corresponding to alternating north-south asymmetries of the bouncing ion population in the sheet center.Those alternating asymmetric plasma sources consequently induce the current sheet flapping motion as a driver.In addition,a substantial particle population with downward motion was observed in the center of a bifurcated current sheet.This population is identified as the quasi-adiabatic particles,and provides a net current opposite to the conventional cross-tail current.
