The Kelvin-Helmholtz instability under Parker-Spiral Interplanetary Magnetic Field conditions at the magnetospheric flanks

Abstract

We have generated fully three-dimensional, high-resolution magnetohydrodynamic (MHD) simulations of the Kelvin-Helmholtz (KH) Instability during Parker-Spiral Interplanetary Magnetic Field (IMF) conditions at the dawnside magnetospheric flank magnetopause. Results of these simulations show that, although the draping of a strong tangential magnetic field component around the magnetopause, tailward of the terminator (due to the Parker-Spiral orientation), tends to stabilize the growth of such instabilities within the shear-flow plane, Kelvin-Helmholtz waves with a k -vector tilted out of this plane may, nonetheless, develop into the nonlinear phase. This result suggests that obliquely propagating KH waves may contribute to the dawn-dusk asymmetries observed in plasma sheet parameters.