Prompt Response of the Dayside Magnetosphere to Discrete Structures within the Sheath Region of a Coronal Mass Ejection

• Published in: Geophysical research letters Vol. 48; no. 11; pp. e2021GL092700 - n/a
• Main Authors: Blum, L. W., Koval, A., Richardson, I. G., Wilson, L. B., Malaspina, D., Greeley, A., Jaynes, A. N.
• Format: Journal Article
• Language: English
• Published: Goddard Space Flight Center Wiley / American Geophysical Union 16.06.2021; John Wiley and Sons Inc
• Subjects: dayside magnetosphere; EMIC waves; Geophysics; ICME sheath; Ionosphere; Magnetosphere: Inner; Magnetospheric Physics; Plasma Waves and Instabilities; Radiation Belts; Research Letter; solar wind; Solar Wind/Magnetosphere Interactions; ICME sheath; EMIC waves; radiation belts; dayside magnetosphere; solar wind
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2021GL092700

A sequence of discrete solar wind structures within the sheath region of an interplanetary coronal mass ejection (ICME) on Nov 06, 2015 caused a series of compressions and releases of the dayside magnetosphere. Each compression resulted in a brief adiabatic enhancement of ions (electrons) driving bursts of electromagnetic ion cyclotron (whistler mode chorus) wave growth across the dayside magnetosphere. Fine-structured rising tones were observed in the EMIC wave bursts, resulting in nonlinear scattering of relativistic electrons in the outer radiation belt. Multipoint observations allow us to study the spatial structure and evolution of these sheath structures as they propagate Earthward from L1 as well as the spatio-temporal characteristics of the magnetospheric response. This event highlights the importance of fine-scale solar wind structure, in particular within complex sheath regions, in driving dayside phenomena within the inner magnetosphere.