The abrupt boundary between a magnetosphere and the surrounding plasma, the magnetopause, has long been known to support surface waves. It was proposed that impulses acting on the boundary might lead to a trapping of these waves on the dayside by the ionosphere, resulting in a standing wave or eigenmode of the magnetopause surface. No direct observational evidence of this has been found to date and searches for indirect evidence have proved inconclusive, leading to speculation that this mechanism might not occur. By using fortuitous multipoint spacecraft observations during a rare isolated fast plasma jet impinging on the boundary, here we show that the resulting magnetopause motion and magnetospheric ultra-low frequency waves at well-defined frequencies are in agreement with and can only be explained by the magnetopause surface eigenmode. We therefore show through direct observations that this mechanism, which should impact upon the magnetospheric system globally, does in fact occur.
The May 2024 Storm: dayside magnetopause and cusps in simulated soft X-Rays
University of Maryland, College Park（马里兰大学帕克分校）；NASA Goddard Space Flight Center（美国宇航局戈达德太空飞行中心）；Applied Physics Laboratory, Johns Hopkins University（约翰斯·霍普金斯大学应用物理实验室）；Space Sciences Laboratory, University of California, Berkeley（加州大学伯克利分校空间科学实验室）；Lockheed Martin Advanced Technology Center（洛克希德·马丁先进技术中心）
Compression and Reconnection Investigations of the MagnetoPause (CRIMP): A Mission Concept to Uncover the Impact of Mesoscale Reconnection and Plasma Outflow Processes at the Dayside Magnetopause
Space Science Center, University of New Hampshire（新罕布什尔大学空间科学中心）；University of Illinois Urbana-Champaign（伊利诺伊大学厄巴纳-香槟分校）；Center for Astrophysics | Harvard & Smithsonian（哈佛与史密森尼天体物理中心）；Massachusetts Institute of Technology（麻省理工学院）；Dartmouth College（达特茅斯学院）；NASA Goddard Space Flight Center（美国宇航局戈达德太空飞行中心）；Georgia State University（佐治亚州立大学）；The Catholic University of America（美利坚天主教大学）；Instituto Tecnológico de Aeronáutica（巴西航空技术研究所）；The Aerospace Corporation（航空航天公司）；Arizona State University（亚利桑那州立大学）；Remcom Inc.（Remcom公司）；NASA Jet Propulsion Laboratory, California Institute of Technology（美国宇航局喷气推进实验室，加州理工学院）；Space Sciences Laboratory, University of California, Berkeley（加州大学伯克利分校空间科学实验室）；University of California, Los Angeles（加州大学洛杉矶分校）；Southwest Research Institute（西南研究院）
