LASP Magnetosphere Seminars

Abstract

The boundary between the Martian ionosphere – populated with heavy ions of planetary origin – and the shocked solar wind in the magnetosheath plays a pivotal role in mediating energy transfer and controlling pathways for atmospheric escape. In this talk, I will present three distinct manifestations of ionosphere–magnetosheath interaction revealed through recent MAVEN observations. The first aspect is steady ion escape through acceleration by the solar wind electric field and subsequent interaction with the magnetosheath. The second phenomenon shows the seasonal effect seen at Martian perihelion, when direct electric field measurements reveal thin and intense layers at the dayside ionosphere-magnetosheath boundary that accelerate ionospheric oxygen, forming a hotter plasma population that creates a localized reservoir for heavy-ion escape. Finally, I will highlight the importance of intermittent disruptions triggered by sudden changes in the interplanetary magnetic field, and associated planetary ion loss, which temporarily increase the total escape by ~1–9%. The findings highlight the dynamicity of ionosphere–magnetosheath interface at Mars, shaped by (1) steady solar wind forcing, (2) localized electric field processes, and (3) transient upstream disturbances which collectively influence the long-term evolution of the Martian atmosphere.