Alfvén: magnetosphere-ionosphere connection explorers
Alfvén: magnetosphere-ionosphere connection explorers
复制标题
Alfvén：磁层-电离层连接探索者
DOI：
10.1007/s10686-011-9273-y
复制
发表时间：
2011
影响因子：
3
通讯作者：
Berthomier M
中科院分区：
文献类型：
--
作者：
Berthomier M
极光是动态的，明亮的显示，优雅的地球高纬度地区的夜空。从太阳发出的太阳风是它们的最终能量来源，但导致极光显示的等离子体物理过程链是复杂的。太阳风驱动的磁层与地球大气层顶部的电离层环境之间的界面处的特殊条件起着核心作用。在极光加速区（AAR）中，持续的电场沿着磁场将磁层电子加速到高能量，从而在它们撞击大气层时激发亮度。空间等离子体的“理想磁流体力学”描述在磁层的大部分区域都很有用，但不能用来理解AAR。AAR已经研究了少量的单航天器任务，揭示了丰富的波粒相互作用，等离子体湍流和非线性加速过程，作用于各种时空尺度的环境。开创性的4航天器集群磁层研究使命现在偶然访问AAR，但它的粒子仪器太慢，无法解决许多关键的等离子体物理现象。Alfvén概念是专门为研究极光而设计的，通过在AAR中进行关键的高时间分辨率，多尺度测量，解决极光等离子体物理学的关键科学问题。使命将产生的新知识将应用于对太阳的研究，即加速太阳风和在其他行星上产生极光的过程。
The aurorae are dynamic, luminous displays that grace the night skies of Earth’s high latitude regions. The solar wind emanating from the Sun is their ultimate energy source, but the chain of plasma physical processes leading to auroral displays is complex. The special conditions at the interface between the solar wind-driven magnetosphere and the ionospheric environment at the top of Earth’s atmosphere play a central role. In this Auroral Acceleration Region (AAR) persistent electric fields directed along the magnetic field accelerate magnetospheric electrons to the high energies needed to excite luminosity when they hit the atmosphere. The “ideal magnetohydrodynamics” description of space plasmas which is useful in much of the magnetosphere cannot be used to understand the AAR. The AAR has been studied by a small number of single spacecraft missions which revealed an environment rich in wave-particle interactions, plasma turbulence, and nonlinear acceleration processes, acting on a variety of spatio-temporal scales. The pioneering 4-spacecraft Cluster magnetospheric research mission is now fortuitously visiting the AAR, but its particle instruments are too slow to allow resolve many of the key plasma physics phenomena. The Alfvén concept is designed specifically to take the next step in studying the aurora, by making the crucial high-time resolution, multi-scale measurements in the AAR, needed to address the key science questions of auroral plasma physics. The new knowledge that the mission will produce will find application in studies of the Sun, the processes that accelerate the solar wind and that produce aurora on other planets.