The plasma sheet and boundary layers under northward IMF: A multi-point and multi-instrument perspective |
| |
| Authors: | MGGT Taylor B Lavraud CP Escoubet SE Milan K Nykyri MW Dunlop JA Davies RHW Friedel H Frey YV Bogdanova A Åsnes H Laakso P Trávnı´cek A Masson H Opgenoorth C Vallat AN Fazakerley AD Lahiff CJ Owen F Pitout Z Pu C Shen QG Zong H Rème J Scudder TL Zhang |
| |
| Institution: | 1. ESA/ESTEC, Keplerlaan 1, 2200 AG Noordwijk, The Netherlands;2. Mullard Space Science Laboratory, University College London, Dorking, Surrey RH5 6NT, UK;3. Space Science and Applications, Los Alamos National Laboratory, Los Alamos, New Mexico, USA;4. Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH, UK;5. The Blackett Laboratory, Imperial College London, London SW7 2AZ, UK;6. Embry-Riddle Aeronautical University, FL, USA;g Space Science and Technology Department, Rutherford Appleton Laboratory, Oxfordshire, UK;h Space Science Laboratory, University of California, Berkley, CA 94720, USA;i Astronomical Institute, Academy of Sciences of the Czech Republic, Czech Republic;j Institute of Atmospheric Physics, Academy of Sciences of the Czech Republic, Czech Republic;k Max-Planck-Institut für Aeronomie, D-37191 Katlenburg-Lindau, Germany;l Laboratoire de Planetologie de Grenoble, BP 53, 38041 Grenoble Cedex 9, France;m School of Earth and Space Sciences, Peking University, Beijing 100871, China;n Centre for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100080, China;o Center for Atmospheric Research, University of Massachusetts, Lowell, USA;p Centre d’Etude Spatiale des Rayonnements, Toulouse, Cedex 4, France;q Department of Physics and Astronomy, University of Iowa, IA 52242, USA;r IWF, Space Research Institute, Austrian Academy of Sciences, Graz, Austria |
| |
| Abstract: | During conditions of northward interplanetary magnetic field (IMF), the near-tail plasma sheet is known to become denser and cooler, and is described as the cold-dense plasma sheet (CDPS). While its source is likely the solar wind, the prominent penetration mechanisms are less clear. The two main candidates are solar wind direct capture via double high-latitude reconnection on the dayside and Kelvin–Helmholtz/diffusive processes at the flank magnetopause. This paper presents a case study on the formation of the CDPS utilizing a wide variety of space- and ground-based observations, but primarily from the Double Star and Polar spacecraft on December 5th, 2004. The pertinent observations can be summarized as follows: TC-1 observes quasi-periodic (∼2 min period) cold-dense boundary layer (compared to a hot-tenuous plasma sheet) signatures interspersed with magnetosheath plasma at the dusk flank magnetopause near the dawn-dusk terminator. Analysis of this region suggests the boundary to be Kelvin–Helmholtz unstable and that plasma transport is ongoing across the boundary. At the same time, IMAGE spacecraft and ground based SuperDARN measurements provide evidence of high-latitude reconnection in both hemispheres. The Polar spacecraft, located in the southern hemisphere afternoon sector, sunward of TC-1, observes a persistent boundary layer with no obvious signature of boundary waves. The plasma is of a similar appearance to that observed by TC-1 inside the boundary layer further down the dusk flank, and by TC-2 in the near-Earth magnetotail. We present comparisons of electron phase space distributions between the spacecraft. Although the dayside boundary layer at Polar is most likely formed via double high-altitude reconnection, and is somewhat comparable to the flank boundary layer at Double Star, some differences argue in favour of additional transport that augment solar wind plasma entry into the tail regions. |
| |
| Keywords: | Plasma sheet Magnetopshere Cold dense plasma sheet Cluster Double star |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
