Work Description

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| README.txt |
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Project Information
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Date: September 30, 2024

Dataset Title: Dataset for Multispecies MHD Simulations of the Crustal Field
Influence at the Mars Magnetotail Current Sheet

Dataset Creators: N. A. Quartey, M. W. Liemohn

Dataset Contact: nquartey@umich.edu (N. A. Quartey)

Key Words:
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mars, magnetotail, current sheet, asymmetry, multispecies, multifluid,
MAVEN, MHD

Research Abstract:
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The magnetotail current sheet of Mars exhibits a dawn-to-dusk
asymmetry that has been seen in satellite observations and MHD
simulations. However, the influence of season has not been
thoroughly investigated in MHD simulations. This investigation
incorporates seasonal variations within the BATS-R-US multispecies
MHD code to examine the influence of crustal magnetic fields and
the ionosphere on the magnetotail current sheet. The solar wind
interaction at Mars is analyzed for the following cases: solar maximum
at perihelion (PERMAX), solar maximum at aphelion (APHMAX), solar minimum
at perihelion (PERMIN), and solar minimum at aphelion (APHMIN). Simulations
show that the current sheet exhibits a duskward (+Y) shift when crustal
fields are included. In simulations that omit crustal sources, the current
sheet remains symmetric along the Y=0 plane. To induce a current sheet
shift in simulations without crustal sources, the ionization rates were
adjusted for the PERMAX and APHMIN cases. The ionization rates were increased
by four orders of magnitude in the PERMAX case, but the current sheet
did not shift. However, the APHMIN current sheet shifted slightly duskward
when the ionization rates were decreased by nine orders of magnitude. These
results differ from those seen in one earlier study but agree with others,
suggesting that the code setups should be scrutinized for refined model comparison.
The simulation results presented in this investigation provide new insights
into the behavior of the magnetotail current sheet.

Key Points:
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- Crustal magnetic fields are found to dominate the magnetotail current sheet shift,
inducing a +Y shift
- Ionization rates must be unrealistically amplified to noticeably influence the
current sheet shift
- The dayside ionosphere shows no contribution to the current sheet
in multispecies MHD simulations without crustal sources

Methodology:
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The data was created using the Block Adaptive Tree Solar wind Roe-Type Upwind Scheme
(BATS-R-US) multispecies MHD code from the Space Weather Modeling Framework (SWMF).
The SWMF is an open-source code available for download at
https://clasp.engin.umich.edu/research/theory-computational-methods/swmf-downloadable-software.

Equations were implemented in the Block Adaptive Tree Solar wind Roe-type Upwind Scheme
(BATS-R-US) multispecies MHD code that include seasons in the simulations, making it
possible to run the solar wind interaction at Mars for PERMAX, APHMAX, PERMIN, and APHMIN.
These cases were run at the University of Michigan Great Lakes High Performance Computing
Cluster and the results were exported using Tecplot 360 EX.

Files contained here:
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- 3d__mhd_By+Parker3DMTGCMBcdaysmax.plt: Contains Multifluid MHD simulation result from the MAVEN
simulation database

- z_0_mhd_permax.plt: Solar maximum at perihelion data in the z=0 plane. Contains magnetic field
and ion density variables
- x_0_mhd_permax.plt: Solar maximum at perihelion data in the x=0 plane. Contains bx result of magnetic
field 2 RM downtail

- z_0_mhd_aphmax.plt: Solar maximum at aphelion data in the z=0 plane. Contains magnetic field
and ion density variables

- z_0_mhd_permin.plt: Solar minimum at perihelion data in the z=0 plane. Contains magnetic field
and ion density variables

- z_0_mhd_aphmin.plt: Solar minimum at aphelion data in the z=0 plane. Contains magnetic field
and ion density variables

- z_0_mhd_permax_omit.plt: Solar maximum at perihelion data without crustal fields in the z=0 plane.
Contains magnetic field and ion density variables without crustal magnetic fields

- z_0_mhd_aphmax_omit.plt: Solar maximum at aphelion data without crustal fields in the z=0 plane.
Contains magnetic field and ion density variables without crustal magnetic fields

- z_0_mhd_permin_omit.plt: Solar minimum at perihelion data without crustal fields in the z=0 plane.
Contains magnetic field and ion density variables without crustal magnetic fields

- z_0_mhd_aphmin_omit.plt: Solar minimum at aphelion data without crustal fields in the z=0 plane.
Contains magnetic field and ion density variables without crustal magnetic fields

- delta.py: Python script that determines the permax, aphmax, permin, and aphmin values

How to use the data and code:
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All .plt files can be accessed using Tecplot 360 EX. The delta.py Python
script can be accessed with any program capable of reading Python 3.9+ files.

Related Publication:
====================
Quartey, N. A. and Liemohn M. W. 2025. Multispecies MHD Simulations of the Crustal Field
Influence at the Mars Magnetotail Current Sheet. Journal of Geophysical Research:
Space Physics

Use and Access:
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This data is made available under an Attribution-NonCommercial 4.0
International license (CC BY-NC 4.0).