Ion-Scale Wave Properties and Enhanced Ion Heating across the Low-Latitude boundary Layer during Kelvin-Helmholtz Instability
| Autor: | Thomas W. Moore, Andrew Dimmock, Katariina Nykyri |
|---|---|
| Přispěvatelé: | Embry-Riddle Aeronautical University, Department of Electronics and Nanoengineering, Aalto-yliopisto, Aalto University |
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Physics
Kelvin-Helmholtz instability ta115 010504 meteorology & atmospheric sciences multi-scale ion heating Plasma sheet Magnetosphere Plasma Magnetosonic wave Geophysics 01 natural sciences Computational physics Solar wind Magnetosheath Physics::Plasma Physics Space and Planetary Science Physics::Space Physics 0103 physical sciences Magnetopause Interplanetary magnetic field 010306 general physics 0105 earth and related environmental sciences |
| Zdroj: | JOURNAL OF GEOPHYSICAL RESEARCH: SPACE PHYSICS. 122(11):128-153 |
| ISSN: | 2169-9380 |
| Popis: | In the Earth's magnetosphere, the magnetotail plasma sheet ions are much hotter than in the shocked solar wind. On the dawn-sector, the cold-component ions are more abundant and hotter by 30-40 percent when compared to the dusk sector. Recent statistical studies of the flank magnetopause and magnetosheath have shown that the level of temperature asymmetry of the magnetosheath is unable to account for this, so additional physical mechanisms must be at play, either at the magnetopause or plasma sheet that contribute to this asymmetry. In this study, we perform a statistical analysis on the ion-scale wave properties in the three main plasma regimes common to flank magnetopause boundary crossings when the boundary is unstable to KHI: hot and tenuous magnetospheric, cold and dense magnetosheath and mixed [Hasegawa et al., 2004]. These statistics of ion-scale wave properties are compared to observations of fast magnetosonic wave modes that have recently been linked to Kelvin-Helmholtz (KH) vortex centered ion heating [Moore et al., 2016]. The statistical analysis shows that during KH events there is enhanced non-adiabatic heating calculated during ion scale wave intervals when compared to non-KH events. This suggests that during KH events there is more free energy for ion-scale wave generation, which in turn can heat ions more effectively when compared to cases when KH waves are absent. This may contribute to the dawn favored temperature asymmetry of the plasma sheet, recent studies suggest KH waves favor the dawn flank during Parker-Spiral (PS) interplanetary magnetic field (IMF). |
| Databáze: | OpenAIRE |
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