= LossMechanismsHarnett = * Loss mechanisms * Non-Thermal Mechanisms * Photochemical Escape : Very important in current atmosphere * • EUV + chemistry * CO2+ +O ⇒ O2+ + CO * O2+ + e ⇒ 2 O* * Ion Pick-up : Carried downstream or reimpact the atmosphere * Sputtering : May have been very important in early atmosphere * Bulk Removal : Wave/plasma instabilities at solar wind/ionosphere boundary