Predicting the long-term solar wind ion-sputtering source at Mercury

摘要: Abstract Maps of the precipitating solar wind proton flux onto Mercury's surface are constructed using a modified Toffoletto–Hill (TH93) model Hermean magnetosphere. Solar and IMF conditions around orbit near aphelion perihelion, respectively, were estimated by reanalyzing Helios 40-s data for times when spacecraft as in orbital range (0.31–0.47 AU). Probability density estimates obtained this way allow us to quantitatively predict likely ion-sputtering source function true anomaly angle planet. Results indicate that sputtering along open fieldlines increases fourfold from significant precipitation closed is twice at perihelion due finite Larmor radius effects. We conclude ion comparatively more important exosphere perihelion.