Dawn-dusk asymmetries of the Earth's dayside magnetosheath in the Magnetosheath InterPlanetary Medium reference frame

Both the local and global magnetosheath plasma parameters regulate the efficiency of processes that dictate the plasma transport across the magnetopause. Previous articles in the form of observational data, magnetohydrodynamic (MHD) simulations, kinetic simulations, and theoretical studies have demonstrated convincingly that the plasma properties in the magnetosheath are asymmetric between the dawn and dusk flanks. This chapter focuses explicitly on quantifying these dawn‐dusk asymmetries for a variety of solar wind conditions and sheds some light on the impact they may have on plasma entry into the magnetosphere. Using THEMIS data, global MHD, and kinetic hybrid simulations, we show that the magnetic field strength, plasma flow speed, temperature anisotropy, and mirror mode occurrence favor the dusk‐flank. On the other hand, ion number density, ion temperature, and plasma turbulence favor the dawn side. We show that some asymmetries depend strongly on solar wind speed (e.g., temperature) IMF orientation (e.g., turbulence), whereas others exhibit no clear dependency (e.g., plasma speed) on conditions we tested. We discuss the impact from these asymmetries on viscous processes at the magnetopause, such as the Kelvin‐Helmholtz instability, and relate this to plasma transport across the magnetopause. We also put our results into context with existing literature on magnetosheath dawn‐dusk asymmetries.