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Multipoint Observations of Magnetosheath Response to Foreshock Transients
Author(s) -
Cai Chunlin,
Wei Xinhua
Publication year - 2020
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1029/2019ja027416
Subject(s) - magnetosheath , foreshock , physics , solar wind , geophysics , population , astrophysics , computational physics , magnetic field , magnetopause , geology , seismology , aftershock , demography , quantum mechanics , sociology
Multispacecraft observations of the magnetosheath responses to various foreshock transients in a single event on 17 March 2004 are reported in this paper. The Cluster spacecraft recorded long‐standing large amplitude ULF waves with both compressive and transverse components in the magnetosheath. Additionally, two transient structures with depressions in density and magnetic field were observed in this period. One structure contains greatly heated and significantly deflected plasmas in the middle and a cold solar wind population at its trailing edge, which is identified as a spontaneous hot flow anomaly with a remnant of the foreshock caviton. It is transmitted through the magneosheath and evolved into a magnetosheath cavity. This cavity was subsequently encountered by the Double Star TC‐1 spacecraft deeper inside the magnetosheath. Meantime, fluxes of hot ions in the energy range of 5–38 keV exhibit quasiperiodic variations. These energetic ions are earthward with pitch angle distributions of alternately field aligned or antifield aligned. A correlation between its flux variations and the transverse fluctuations of the ULF waves is found. Moreover, magnetosheath filamentary structures with a series of anticorrelated oscillations of density and temperature were observed simultaneously.