Data from: IMF control of electron aurora across Mars' crustal magnetic fields: Insights into electron sources

We investigate Martian electron aurora utilizing 130.4 nm auroral
observations from the Emirates Mars Ultraviolet Spectrograph and IMF clock
angle measurements and estimates from MAVEN. Analysis reveals that
>5 R aurora occurrence in a given region can vary by up to a factor
of seven with IMF orientation, generally highest for southward IMF and
lowest for westward IMF, with higher auroral occurrence post-dusk,
decreasing toward and past midnight before increasing again towards dawn.
A broad diversity of IMF and local time dependence of aurora occurrence is
observed across Mars’ crustal magnetic fields. The polarity of a given
crustal field determines whether its field lines preferentially
magnetically connect to dayside ionospheric or nightside magnetotail
electron sources in the post-dusk or pre-dawn sectors. We thus establish a
“source preference metric”, i.e., the excess likelihood of aurora when
likely magnetically connected to the nightside versus dayside. A wide
range of source preferences is observed across the crustal field features,
with some showing higher occurrence for night sources, day sources, or
neither, often differently when in the post-dusk or pre-dawn sectors. A
generally stronger nightside source preference is found for radially
inward crustal fields in the predawn sector, and for weaker outward
crustal fields in the post-dusk sector. These results highlight the
complex and dynamic nature of Mars’ magnetic topology in controlling
auroral electron access. Future studies integrating in situ electron
measurements with synoptic and limb auroral imaging will further constrain
the relative contributions of dayside and magnetotail electron populations
to Mars’ auroral processes.