DOI: 10.5061/dryad.vt4b8gv4x
title: Data from: IMF control of electron aurora across Mars' crustal magnetic fields: Insights into electron sources

description: 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
 &gt;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.
description: # Data from: IMF control of electron aurora across Mars' crustal
 magnetic fields: Insights into electron sources Dataset DOI:
 [10.5061/dryad.vt4b8gv4x](10.5061/dryad.vt4b8gv4x) ## Description of the
 data and file structure The 3D MHD simulation outputs span from **07:00 to
 07:20 UT on November 15, 2022**, with files saved at **one-minute
 intervals**. Each file name encodes the time information in the format:\
 `t000hhmm00_nxxxxxxx.dat.gz` The outputs are stored in **ascii format**,
 and each file contains the following plasma variables in order: `"X
 [R]" "Y [R]" "Z [R]" "B_x [nT]"
 "B_y [nT]" "B_z [nT]" "B1_x [nT]" "B1_y
 [nT]" "B1_z [nT]"` Of those variables, X, Y, Z: location in
 MSO coordinate; B_x, B_y, B_z: total magnetic field vector in MSO, and
 B1_x, B1_y, B1_z: induced magnetic field in MSO. The crustal magnetic
 field is given by the vector subtraction of the induced field from the
 total field.  * 3d__ful_1_t00070000_n1745129_B.dat.gz *
 3d__ful_1_t00070100_n1748841_B.dat.gz *
 3d__ful_1_t00070200_n1752546_B.dat.gz *
 3d__ful_1_t00070300_n1756245_B.dat.gz *
 3d__ful_1_t00070400_n1759942_B.dat.gz *
 3d__ful_1_t00070500_n1763637_B.dat.gz *
 3d__ful_1_t00070600_n1767332_B.dat.gz *
 3d__ful_1_t00070700_n1771026_B.dat.gz *
 3d__ful_1_t00070800_n1774720_B.dat.gz *
 3d__ful_1_t00070900_n1778415_B.dat.gz *
 3d__ful_1_t00071100_n1785804_B.dat.gz *
 3d__ful_1_t00071200_n1789500_B.dat.gz *
 3d__ful_1_t00071300_n1793198_B.dat.gz *
 3d__ful_1_t00071400_n1796898_B.dat.gz *
 3d__ful_1_t00071500_n1800600_B.dat.gz *
 3d__ful_1_t00071600_n1804304_B.dat.gz *
 3d__ful_1_t00071700_n1808011_B.dat.gz *
 3d__ful_1_t00071800_n1811722_B.dat.gz *
 3d__ful_1_t00071900_n1815436_B.dat.gz *
 3d__ful_1_t00072000_n1819156_B.dat.gz ##