Details

Autor(en) / Beteiligte

• Dong, Y.
• Fang, X.
• Brain, D. A.
• McFadden, J. P.
• Halekas, J. S.
• Connerney, J. E.
• Curry, S. M.
• Harada, Y.
• Luhmann, J. G.
• Jakosky, B. M.

Titel

Strong plume fluxes at Mars observed by MAVEN: An important planetary ion escape channel

Ist Teil von

• Geophysical research letters, 2015-11, Vol.42 (21), p.8942-8950

Ort / Verlag

Washington: Blackwell Publishing Ltd

Erscheinungsjahr

2015

Quelle

Wiley Online Library

Beschreibungen/Notizen

• 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 along the upstream electric field over the north pole region of the Mars‐Sun‐Electric field (MSE) coordinate system, antisunward ion fluxes in the tail region, and much weaker upstream pickup ion fluxes. A statistical study of O+ fluxes using 3 month MAVEN data shows that the plume is a constant structure with strong fluxes widely distributed in the MSE northern hemisphere, which constitutes an important planetary ion escape channel. The escape rate through the plume is estimated to be ~30% of the tailward escape and ~23% of the total escape for > 25 eV O+ ions. Key Points Three escaping planetary ion populations near Mars are identified in MAVEN observations MAVEN observed a substantial plume with strong escaping ion fluxes over the MSE north pole region The plume contributes ~23% to the total >25 eV O+ escape of ~2 × 1024 s−1