Ionospheric Production Variation in Super-Alfvénic Regime: From Lunar-type Sputtering to Titan-type Ionospheric Interaction.

Abstract:

Solar wind plasma interactions with planetary obstacles having fully developed ionospheres such as Titan, and weakly sputtered particles such as Earth's moon are topics of active research. We aim at extending our understanding of such types of interaction by looking at intermediate states between weakly sputtering planetary obstacle and ionosphere-rich obstacles. We present results from our hybrid model AIKEF of planetary obstacles, using a Chapman profile for the ionosphere, and characterize them using currents flowing around the interaction region. Among our results, we evaluate the ionospheric conductivity at each obstacle related to its ionospheric production, giving an estimation of the ion production that triggers a bow shock. We explore two cases of ionospheric species, hydrogen and oxygen, separately. Results show that an oxygen generated ionosphere requires less production to trigger a bow shock than a hydrogen-generated ionosphere, as well as differences in the pick-up process and the induced asymmetry of the interaction region. The final results are summarized into three-dimensional schematics representing qualitative changes when tweaking the production.