Mirror Mode Storms at the Magnetosheaths of Earth and Mars

Wave-particle interactions are important in the momentum and energy transfer across a planetary magnetosheath, from the solar wind upstream of the bow shock to the magnetosphere. In the highly perturbed magnetosheath plasma of Earth and Mars, anisotropic ion distributions have enough free energy to drive low-frequency instabilities such as the mirror mode instability. The resulting mirror mode waves are therefore common structures inside those magnetosheaths. In the solar wind, long trains of holes and peaks in the magnetic field magnitude that can last for hours have been reported (Russell et al.,2009; Enriquez-Rivera et al., 2013). In this work, we explore the existence of mirror mode storms in the sheaths of the Earth and Mars like those observed in solar wind regions. We study the characteristics of a few observed storms and possible dependencies on factors such as the plasma beta and distance from the bow shock.  We also study the evolution of the ion distributions associated with mirror mode structures to investigate the waves' origin.