Kelvin‐Helmholtz Stability Analysis as a Function of Dipole Tilt and Solar Wind Property

Abstract Kelvin‐Helmholtz instabilities (KHIs) play a critical role in facilitating mass and momentum transport across the magnetopause boundary. Recent studies have demonstrated that KHI occurrence exhibits both seasonal and diurnal variability, with enhanced activity when Earth's magnetic dipole is more closely aligned with the northward direction in geocentric solar ecliptic (GSE) coordinates (Kavosi et al., 2023, https://doi.org/10.1038/s41467‐023‐37485‐x ). To investigate this behavior, we examine the dependence of KHI stability on the relative orientation of Earth's dipole field and the interplanetary magnetic field (IMF). Using a simplified model of the solar wind, IMF, and Earth's dipolar magnetic field—assuming a parabolic magnetopause geometry—we consider how the draped magnetic field of the Parker spiral and seasonal changes in Earth's dipole orientation modify the stability of the magnetopause boundary and lead to biases and asymmetries in KHI occurrence.