Submitting Campus
Daytona Beach
Department
Physical Sciences
Document Type
Article
Publication/Presentation Date
3-13-2024
Abstract/Description
The Kelvin‐Helmholtz (KH) instability can transport mass, momentum, magnetic flux, and energy between the magnetosheath and magnetosphere, which plays an important role in the solar‐wind‐ magnetosphere coupling process for different planets. Meanwhile, strong density and magnetic field asymmetry are often present between the magnetosheath (MSH) and magnetosphere (MSP), which could affect the transport processes driven by the KH instability. Our magnetohydrodynamics simulation shows that the KH growth rate is insensitive to the density ratio between the MSP and the MSH in the compressible regime, which is different than the prediction from linear incompressible theory. When the interplanetary magnetic field (IMF) is parallel to the planet's magnetic field, the nonlinear KH instability can drive a double mid‐latitude reconnection (DMLR) process. The total double reconnected flux depends on the KH wavelength and the strength of the lower magnetic field. When the IMF is anti‐parallel to the planet's magnetic field, the nonlinear interaction between magnetic reconnection and the KH instability leads to fast reconnection (i.e., close to Petschek reconnection even without including kinetic physics). However, the peak value of the reconnection rate still follows the asymmetric reconnection scaling laws. We also demonstrate that the DMLR process driven by the KH instability mixes the plasma from different regions and consequently generates different types of velocity distribution functions. We show that the counter‐streaming beams can be simply generated via the change of the flux tube connection and do not require parallel electric fields.
Publication Title
JGR Space Physics
DOI
https://doi.org/10.1029/2023JA032234
Publisher
AGU Advancing Earth and Space Sciences
Grant or Award Name
NASA Grants 80NSSC18K1108, 80NSSC18K1381, 80NSSC22K0949, 80NSSC20K1279, 80NSSC22K0304, and 80NSSC23K0899, NSF Grants 2308853 and DOE DE‐SC0022952
Scholarly Commons Citation
Ma, X., Delamere, P., Nykyri, K., Otto, A., Eriksson, S., Chai, L., et al. (2024). Density and magnetic field asymmetric Kelvin‐Helmholtz instability. Journal of Geophysical Research: Space Physics, 129, e2023JA032234. https://doi.org/10. 1029/2023JA032234
Included in
External Galaxies Commons, Physical Processes Commons, Stars, Interstellar Medium and the Galaxy Commons, The Sun and the Solar System Commons
