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Reduced Atmospheric Ion Escape Above Martian Crustal Magnetic Fields
Author(s) -
Fan Kai,
Fraenz Markus,
Wei Yong,
Han Qianqian,
Dubinin Eduard,
Cui Jun,
Chai Lihui,
Rong Zhaojin,
Zhong Jun,
Wan Weixing,
Mcfadden James,
Connerney J.E.P.
Publication year - 2019
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 - 10.1029/2019gl084729
Subject(s) - martian , mars exploration program , atmospheric escape , flux (metallurgy) , atmosphere of mars , solar wind , ion , atmosphere (unit) , geophysics , astrobiology , geology , martian surface , magnetic field , physics , atmospheric sciences , materials science , meteorology , quantum mechanics , metallurgy
Martian crustal fields were considered as too weak to have a distinctive effect on global escape rates of Martian heavy ions. However, new observations by the Mars Atmosphere and Volatile Evolution mission reveal a more precise result and show a notably lower atmospheric ion escape region above the area of the strongest crustal fields. A comparison between the fluxes of high and low energy O + ions suggests that the strongest crustal fields may trap low energy ions and reduce the solar wind pick‐up efficiency while high energy ions form a flux depletion above the crustal field. Statistical results indicate a maximum reduction of the global escape flux by nearly 35% when the strongest crustal field region is oriented sunward. This is the first time that the protective effect of the crustal fields on heavy planetary ions has been observed and it might indicate a more effective protection of atmospheres by stronger magnetic fields like at Earth.