The escape of O and C from the early Martian atmosphere due to ion pick up
Abstract
We present loss rates of O and C from the early Martian atmosphere due to ion pick up for four points in time in its history corresponding to 1, 3, 10, and 20 times the present solar EUV flux. Based on density profiles of the background atmosphere of O and C and on the profiles of suprathermal O and C produced by dissociative recombination, ionization rates are estimated and the trajectories of these newly created ions are calculated by means of a hybrid code, taking into account the interaction with the magnetized solar wind. The impact rate of ions entering the atmosphere as well as the ion escape rates are determined.Moreover, we compare these ion loss rates to the corresponding rates of suprathermal O and C. We found that ion pick up loss becomes comparable with neutral escape rates and that the former dominates the escape for 20 EUV. This suggests that up to about 1 Gyr after Mars' origin, the main loss mechanism is ion pick up process, whereas loss due to suprathermal atoms was more efficient during later times.
- Publication:
-
42nd COSPAR Scientific Assembly
- Pub Date:
- July 2018
- Bibcode:
- 2018cosp...42E2008L