The Influence of Solar Irradiation and Solar Wind Conditions on Heavy Ion Escape from Mars

We apply a recently proposed method to estimate heavy ion escape from Mars. The method combines in situ observations with a hybrid plasma model, which treats ions as particles and electrons as a fluid. With this method, we investigate how solar upstream conditions, including solar extreme ultraviolet (EUV) radiation, solar wind dynamic pressure, and interplanetary magnetic field (IMF) strength and cone angle, affect the heavy ion loss. The results indicate that the heavy ion escape rate is greater in high EUV conditions. The escape rate increases with increasing solar wind dynamic pressure, and decreases as the IMF strength increases. The ion escape rate is highest when the solar wind is parallel to the IMF and lowest when they are perpendicular. The plume escape rate decreases when the solar wind convective electric field increases.

Automated summary

This study applies a new method to estimate the escape of heavy ions from Mars. It shows that solar upstream conditions, such as high EUV radiation, increasing solar wind dynamic pressure, and decreasing IMF strength, have an impact on the heavy ion loss. The escape rate is highest under high EUV conditions, increases with increasing solar wind dynamic pressure, and decreases with increasing IMF strength.