Ion escape fluxes from Mars
نویسندگان
چکیده
[1] A 3D, multi-species, non-ideal MHD numerical code was used to calculate the ion escape fluxes from Mars. The calculations were carried out for six cases with different nominal solar wind, solar cycle and crustal field orientation conditions and the total escape fluxes (the sum of the three major ionospheric species, O, O2 , and CO2 ) varied by about an order of magnitude from 2.7 10 to 2.4 10 sec . These results were compared to the recently measured Mars Express results of 3.2 10 sec 1 (O, O2, and CO2), which were obtained near solar cycle minimum conditions, indicating a good agreement between measured and calculated fluxes. We also calculated the escape flux for ‘‘extremely’’ high solar wind conditions which leads to a flux of 3 10 sec . Citation: Ma, Y.-J., and A. F. Nagy (2007), Ion escape fluxes from Mars, Geophys. Res. Lett., 34, L08201, doi:10.1029/2006GL029208.
منابع مشابه
Strong plume fluxes at Mars observed by MAVEN: An important planetary ion escape channel
We present observations by the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission of a substantial plume-like distribution of escaping ions from the Martian atmosphere, organized by the upstream solar wind convection electric field. From a case study of MAVEN particle-and-field data during one spacecraft orbit, we identified three escaping planetary ion populations: plume fluxes mainly alon...
متن کاملThe spatial distribution of planetary ion fluxes near Mars observed by MAVEN
We present the results of an initial effort to statistically map the fluxes of planetary ions on a closed surface around Mars. Choosing a spherical shell ~1000 km above the planet, we map both outgoing and incoming ion fluxes (with energies >25 eV) over a 4month period. The results show net escape of planetary ions behind Mars and strong fluxes of escaping ions from the northern hemisphere with...
متن کاملTest particle comparison of heavy atomic andmolecular ion distributions at Mars
This study uses the Mars Test Particle simulation to create virtual detections of O+, O2 , and CO2 in an orbital configuration in the Mars space environment. These atomic and molecular planetary pickup ions are formed when the solar wind directly interacts with the neutral atmosphere, causing the ions to be accelerated by the background convective electric field. The subsequent ion escape is th...
متن کاملPlasma clouds and snowplows: Bulk plasma escape from Mars observed by MAVEN
We present initial Mars Atmosphere and Volatile EvolutioN (MAVEN) observations and preliminary interpretation of bulk plasma loss from Mars. MAVEN particle and field measurements show that planetary heavy ions derived from the Martian atmosphere can escape in the form of discrete coherent structures or “clouds.” The ions in these clouds are unmagnetized or weakly magnetized, have velocities wel...
متن کاملMass Fractionation in Hydrodynamic Escape
We show that mas s fractionation occurs during the course of hydrodynamic escape of gases f rom the a tmosphe re of an inner planet. Light gases escape more readily than heavy gases. The resul tant fract ionat ion as a funct ion of mas s yields a linear or concave downward plot in a graph of logari thm of remaining inventory against a tomic mass . An episode of hydrodynamic escape early in the ...
متن کامل