Premium
Cold Dense Ion Outflow Observed in the Martian‐Induced Magnetotail by MAVEN
Author(s) -
Inui S.,
Seki K.,
Namekawa T.,
Sakai S.,
Brain D. A.,
Hara T.,
McFadden J. P.,
Halekas J. S.,
Mitchell D. L.,
Mazelle C.,
DiBraccio G. A.,
Jakosky B. M.
Publication year - 2018
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2018gl077584
Subject(s) - outflow , martian , mars exploration program , atmosphere of mars , atmospheric escape , physics , flux (metallurgy) , ion , atmosphere (unit) , atmospheric sciences , environmental science , geophysics , geology , astrobiology , meteorology , materials science , quantum mechanics , metallurgy
Cold ion outflow is one of the candidate processes to cause significant atmospheric escape from Mars. We here report on the cold dense heavy ion outflow event observed in Martian‐induced magnetotail by Mars Atmosphere and Volatile EvolutioN (MAVEN) on 4 December 2014. In the outflow event, the cold dense heavy ion outflow was observed only in south dusk downward convection electric field (E) lobe. During the event, the strong crustal magnetic field was located on dayside of Mars. It suggests that combination of minimagnetosphere and downward E facilitates the cold dense heavy ion outflow. In order to estimate the CO 2 + density, we adopted a fitting method of log‐normal distribution to the O 2 + time of flight distributions to eliminate O 2 + contamination in the CO 2 + time of flight data. Contribution of O 2 + , O + , and CO 2 + to the total heavy ions (~134 cm −3 ) is about 71%, 26%, and 3%, respectively. Average heavy ion flux was ~5.4 × 10 7 cm −2 s −1 , assuming the escape velocity at 2,000‐km altitude.