Transmission of an ICME Sheath Into the Earth's Magnetosheath and the Occurrence of Traveling Foreshocks

Abstract

Interplanetary coronal mass ejections (ICMEs) are massive clouds of plasma and magnetic field that originate from vast eruptions in the Sun's corona. They transfer energy in interplanetary space and are the main drivers of space weather at the Earth (e.g., Gonzalez et al., 1999Gonzalez et al., , 2011Kilpua, Balogh, et al., 2017; and references therein). An ICME consists of a magnetic ejecta which drives a shock and sheath region when traveling with supermagnetosonic speeds relative to the solar wind in interplanetary space. Interplanetary shocks, including those not associated with ICMEs, have been extensively studied (e.g.,

A Mosaic of the Inner Heliosphere: Three Carrington Rotations During the Whole Heliosphere and Planetary Interactions Interval

“…However, the coherency began to break down with increased interspacecraft separations in GSE Y, suggesting mesoscale variability in the solar wind was beginning to increasingly affect comparisons between the L1‐orbiting spacecraft, consistent with investigations of mesoscale variability in CME sheaths (Ala‐Lahti et al., 2020). The current constellations of assets do not allow for robust investigations into this structuring across scales, but these findings are in line with calls for dedicated missions to investigate the nature of the mesoscale solar wind (e.g., Allen et al., 2022; Maruca et al., 2021) and consistent with previous studies attempting to elucidate mesoscale structures in the solar wind (e.g., Ala‐Lahti et al., 2020; Neugebauer et al., 2006; Neugebauer & Giacalone, 2005; Owens et al., 2017) and potential effects on the geospace system (e.g., Ala‐Lahti et al., 2021).…”

A theoretic analysis of magnetoactive GES-based turbulent solar plasma instability

“…In a special case of reduced plane parallel geometry ( ξ → ∞ , planar), our spherical ( ξ ∞ , non-planar) analysis shows a fair corroboration with the previously reported planar investigation founded on the same GES-based solar plasma direction (Gohain & Karmakar 2018 ). It shows a unique feature of the proposed GESbased theory against the diversified sheath formalisms available in the literature (Formisano et al 1973 ;Fairfield 1976 ;Mozer et al 1978 ;Gravier et al 2000 Langner et al 2006 ;Phan et al 2007 ;Richardson et al, 2008Richardson et al, , 2022Siscoe & Odstrcil 2008 ;Lazarian & Opher 2009 ;Richardson & Wang 2010 ;Schoeffler et al 2011 ;Wang et al 2012 ;Petrinec 2013 ;Robertson 2013 ;Lyatsky et al 2016 ;Chowdhury et al 2017 ;Chasapis et al 2018 ;Macek et al 2018 ;Rout et al 2018 ;Janvier et al 2019 ;Shaikh et al 2020 ;Ala-Lahti et al 2021 ;Sow Mondal et al 2021 ). An e xtensiv e comparison of the salient parametric features of the modified GES structures of current concern (Dwivedi et al 2007 ;Karmakar & Dwivedi 2011 ;Goutam & Karmakar 2015 ;Das & Karmakar 2022 ;Sarma & Karmakar 2022 ) against various other sheath (non-GES) patterns based on our integrated conceptional fabric for the sake of instant reference is briefly given in Appendix C .…”

Magnetospheric Sources of Theta Aurora: A Case Study Comparing Observations With SWMF Global Simulation

“…The TPA was recorded over the southern hemisphere by the FUV‐WIC camera onboard the Imager for Magnetopause‐to‐Aurora Global Exploration (IMAGE) spacecraft (Mende et al., 2000), during an interplanetary coronal mass ejection (ICME) sheath period following a solar wind shock impact at the Earth's bow shock (around ∼0241 UT) (Ala‐Lahti et al., 2021). Figure 1c shows the high solar wind velocity and high solar wind density during the ICME sheath period after the shock.…”

“…Figure 1c shows the high solar wind velocity and high solar wind density during the ICME sheath period after the shock. The TPA develops after at least 2 hr of small but predominantly positive IMF B Z in the ICME sheath, and remains visible as the IMF B Z turns southward during the ICME magnetic cloud passage (Ala-Lahti et al, 2021), with the ring current at the level of SMR ∼ 100 nT (Figure 1d) and peak auroral electrojet index activity SML < 1,500 nT (Figure 1e; Gjerloev, 2012). These observations are in line with previous studies that have also shown TPAs to exist during negative IMF B Z conditions after prolonged intervals of positive IMF B Z (Craven et al, 1991;P.…”