Kelvin-Helmholtz Vortices as an Interplay of Magnetosphere-Ionosphere Coupling

Autor: K.-J. Hwang, J. M. Weygand, D. G. Sibeck, J. L. Burch, M. L. Goldstein, C. P. Escoubet, E. Choi, K. Dokgo, B. L. Giles, C. J. Pollock, D. J. Gershman, C. T. Russell, R. J. Strangeway, R. B. Torbert
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Frontiers in Astronomy and Space Sciences, Vol 9 (2022)
Druh dokumentu: article
ISSN: 2296-987X
DOI: 10.3389/fspas.2022.895514
Popis: The solar wind-magnetosphere interaction drives diverse physical processes on the flanks of Earth’s magnetopause, and in turn these processes couple to the ionosphere. We investigate simultaneous multipoint in-situ spacecraft and ground-based measurements to determine the role of Kelvin-Helmholtz waves at the Earth’s magnetopause and the low-latitude boundary layer in the magnetosphere-ionosphere coupling process. Nonlinear Kelvin-Helmholtz waves develop into flow vortices that twist and/or shear flux tube magnetic fields, thereby generating localized field-aligned currents. Kelvin-Helmholtz vortices on the dusk (dawn) flanks of the magnetosphere generate clockwise (counter-clockwise) rotations and upward (downward) field-aligned currents inside the flux tubes, consistent with the region-1 field-aligned current. We present in-situ MMS and Cluster spacecraft observations of Kelvin-Helmholtz vortices at the magnetopause that map to the poleward edge of the auroral regions. The FAST spacecraft and the ground-based magnetometers from which spherical elementary currents (acting as a proxy for vertical currents) can be calculated observe corresponding field-aligned current signatures. This study demonstrates the role played by the Kelvin-Helmholtz waves in linking magnetopause boundary fluctuations to ionospheric phenomena.
Databáze: Directory of Open Access Journals