Work Description

Date: 06-13-2022

Authors: K. J. Roeten, S. W. Bougher

Title: M-GITM datasets used for a modeling study of the mean impacts of subgrid-scale
gravity waves on thermospheric velocities and temperatures at Mars.

Associated Publication:

Roeten, K. J., Bougher, S. W., Yigit, E., Medvedev, A. S., Benna, M., Elrod, M. K. (2022).
Impacts of gravity waves in the Martian thermosphere: The Mars Global Ionosphere-
Thermosphere Model coupled with a whole atmosphere gravity wave scheme. Journal
of Geophysical Research: Planets.

Overview:

The datasets included here are output from M-GITM (Mars Global Ionosphere-
Thermosphere Model), a 3-D ground-to-exosphere numerical model (Bougher et al.,
2015). They were created for a study of the impacts of subgrid-scale gravity waves on
the thermosphere.

Methods:

The provided set of M-GITM datasets include results from simulations of the Mars
atmosphere which utilize the gravity wave parameterization scheme of Yigit et al. (2008)
(i.e., labeled "withgw") and simulations that do not utilize this scheme (i.e., labeled
"nogw").

Some of these datasets were specifically generated to be used in comparison with either
wind or temperature datasets from the MAVEN (Mars Atmosphere and Volatile
Evolution) / NGIMS (Neutral Gas and Ion Mass Spectrometer) instrument. These
MAVEN/NGIMS datasets are publicly available and can be found on the Planetary Data
System at http://pds-
atmospheres.nmsu.edu/data_and_services/atmospheres_data/MAVEN/ngims.html.

Files with three different formats of M-GITM output are included. Those labeled
"ZonalAvg" include M-GITM output that has been zonally and temporally averaged (over
15 days). Files labeled "WindExtraction" or "TempExtraction" contain wind or
temperature profiles, respectively, extracted along the same latitude, local time, and
altitude trajectory flown by MAVEN for the time period simulated by M-GITM. These
extractions (i.e. flythroughs) are not averaged, and include M-GITM output
corresponding to each orbit in the MAVEN observational campaign.

Files (13 total):

MGITM_ZonalAvg_Ls270nogw.csv
MGITM_ZonalAvg_Ls270withgw.csv
MGITM_ZonalAvg_Ls180nogw.csv
MGITM_ZonalAvg_Ls270withgw.csv
MGITM_ZonalAvg_sourceflux1.csv
MGITM_ZonalAvg_sourceflux2.csv
MGITM_ZonalAvg_wavelength.csv
MGITM_WindExtraction_Jan2017_nogw.csv
MGITM_WindExtraction_Jan2017_withgw.csv
MGITM_WindExtraction_May2017_nogw.csv
MGITM_WindExtraction_May2017_withgw.csv
MGITM_TempExtraction_DD2_nogw.csv
MGITM_TempExtraction_DD2_withgw.csv

File Description:

MGITM_ZonalAvg_Ls270nogw.csv: Simulation for a Ls=270 solstice (11-28-2016).
Output has been zonally and temporally averaged over a 15-day period. Run without
utilizing the gravity wave scheme.

MGITM_ZonalAvg_Ls270withgw.csv: Simulation for a Ls=270 solstice (11-28-2016).
Output has been zonally and temporally averaged over a 15-day period. Run WITH the
gravity wave scheme included.

MGITM_ZonalAvg_Ls180nogw.csv: Simulation for a Ls=180 equinox (05-22-2018).
Output has been zonally and temporally averaged over a 15-day period. Run without
utilizing the gravity wave scheme.

MGITM_ZonalAvg_Ls180withgw.csv: Simulation for a Ls=180 equinox (05-22-2018).
Output has been zonally and temporally averaged over a 15-day period. Run WITH the
gravity wave scheme included.

MGITM_ZonalAvg_sourceflux1.csv: Sensitivity test simulation for the Ls=270 solstice
(11-28-2016). Everything within the simulation is kept the same as for the
MGITM_ZonalAvg_Ls270withgw.csv case, except for changing the maximum source flux
parameter within the gravity wave scheme from 0.0025 m2/s2 to 0.00025 m2/s2. The
maximum source flux parameter helps determine the shape of the momentum spectra
used at the starting level for the gravity wave scheme within the model. See Roeten et
al. (2022) and sources within for more details.

MGITM_ZonalAvg_sourceflux2.csv: Sensitivity test simulation for the Ls=270 solstice
(11-28-2016). Everything within the simulation is kept the same as for the
MGITM_ZonalAvg_Ls270withgw.csv case, except for changing the maximum source flux
parameter within the gravity wave scheme from 0.0025 m2/s2 to 0.005 m2/s2. The
maximum source flux parameter helps determine the shape of the momentum spectra
used at the starting level for the gravity wave scheme within the model. See Roeten et
al. (2022) and sources within for more details.

MGITM_ZonalAvg_wavelength.csv: Sensitivity test simulation for the Ls=270 solstice
(11-28-2016). Everything within the simulation is kept the same as for the
MGITM_ZonalAvg_Ls270withgw.csv case, except for changing the horizontal
wavelength from 300 km to 200 km. This representative horizontal wavelength is used
by all wave harmonics within the scheme. See Roeten et al. (2022) and sources within
for more details.

MGITM_WindExtraction_Jan2017_nogw.csv: Flythrough of the M-GITM simulation of
the January 11-13, 2017 MAVEN/NGIMS wind observational campaign. This file
contains each orbit of a 10-orbit M-GITM flythrough done for the time period and along
the same local time, latitude, and altitude trajectory of the corresponding observational
campaign by MAVEN to measure thermospheric winds. This M-GITM simulation does
not include the gravity wave scheme. This M-GITM output has not been averaged.

MGITM_WindExtraction_Jan2017_withgw.csv: Same as above for
MGITM_WindExtraction_Jan2017_nogw.csv, but uses the gravity wave
parameterization scheme in the model simulations.

MGITM_WindExtraction_May2017_nogw.csv: Flythrough of the M-GITM simulation of
the May 30 - June 1, 2017 MAVEN/NGIMS wind observational campaign. This file
contains each orbit of a 10-orbit M-GITM flythrough done for the time period and along
the same local time, latitude, and altitude trajectory of the corresponding observational
campaign by MAVEN to measure thermospheric winds. This M-GITM simulation does
not include the gravity wave scheme. This M-GITM output has not been averaged.

MGITM_WindExtraction_May2017_withgw.csv: Same as above for
MGITM_WindExtraction_May2017_nogw.csv, but uses the gravity wave
parameterization scheme in the model simulations.

MGITM_TempExtraction_DD2_nogw.csv: Flythrough of the M-GITM simulation of the
Deep Dip 2 (DD2) MAVEN observational campaign from April 17-22, 2015. This file
contains each orbit of a 28-orbit M-GITM flythrough done for the time period and along
the same local time, latitude, and altitude trajectory of the corresponding observational
campaign by MAVEN. Note: DD2 is not a NGIMS wind campaign, but one in which the
typical NGIMS compositional measurements are taken; the corresponding M-GITM
flythrough contains temperatures. This M-GITM simulation does not include the gravity
wave scheme. This M-GITM output has not been averaged.

MGITM_TempExtraction_DD2_withgw.csv: Same as above for
MGITM_TempExtraction_DD2_nogw.csv:, but uses the gravity wave parameterization
scheme in the model simulations.

-----------------------------------------------------------------------------------------------------------

Zonal Averages ("ZonalAvg"):

M-GITM zonally averaged results are on a regular GEO grid (Latitude-Altitude):
Latitude (36 elements): -87.5 to 87.5 in a 5.0 degree interval
Altitude (101 elements): 1.25 to 251.25 km in a 2.5 km interval

Fields (9 for gravity wave cases, 6 for cases without gravity waves)
1) Altitudes (km)
2) Latitudes (degrees)
3) Density (kg/m3)
4) Temperature (K)
5) Zonal Wind (m/s)
6) Meridional Wind (m/s)
7) Zonal Gravity Wave Drag (m/s/sol)
8) Meridional Gravity Wave Drag (m/s/sol)
9) Net Gravity Wave Heating/Cooling (K/sol)

File format:

Each of these nine fields listed above are presented as a 2D matrix in latitude and
altitude that have been concatenated on top of each other such that the long dimension
of the matrix is 9x101 or 6x101, depending on whether it is a simulation that includes
the effects of gravity waves. The first column contains an integer number which
denotes the variable being viewed and is not actual model output. The values in this
column correspond to the numbers in the list above. These files contain no headers.

-----------------------------------------------------------------------------------------------------------

Wind Extractions ("WindExtraction"):

Model flythroughs are extracted from M-GITM results which employ a regular GEO grid
(Latitude-Longitude-Altitude). For wind extractions, the M-GITM output file
corresponding to the time at which noon local time occurs at 0 degrees longitude was
used. Flythrough profiles show this M-GITM output along the altitude, latitude, local
time trajectory flown by the MAVEN spacecraft for specific orbits.

Variables (7)
- Orbit_num (Corresponding MAVEN orbit number)
- Alt (Altitude, km)
- Lat (Latitude, degrees)
- LT (Local time, hr)
- CO2 (CO2 number density, #/m3)
- Zonal_Wind (Zonal wind, m/s)
- Merid_Wind (Meridional wind, m/s)

File format:

Each variable is listed in a separate column. M-GITM profiles begin at the top of the
inbound segment of the MAVEN orbit, go through periapsis, and end at the top of the
outbound segment. The M-GITM output for each orbit has been concatenated on top of
each other within this file, and can be distinguished by the orbit number in the first
column. The first row in the file contains the header, which is composed of all the
variable names listed above.

-----------------------------------------------------------------------------------------------------------

Temperature Extractions ("TempExtraction"):

Model flythroughs are extracted from M-GITM results which employ a regular GEO grid
(Latitude-Longitude-Altitude). Flythrough profiles show this M-GITM output along the
altitude, latitude, local time trajectory flown by the MAVEN spacecraft for specific
orbits.

Variables (9)
- Orbit_num (Corresponding MAVEN orbit number)
- Alt (Altitude, km)
- Lat (Latitude, degrees)
- LT (Local time, hr)
- Rho (Density, kg/km3)
- Temp (Temperature, K)
- CO2 (CO2 number density, #/m3)
- O (O number density, #/m3)
- He (He number density, #/m3)

File Format:

Each variable is listed in a separate column. M-GITM profiles begin at the top of the
inbound segment of the MAVEN orbit and end at the location of spacecraft periapsis.
Since MAVEN/NGIMS derived temperature profiles typically only utilize the inbound
segment of the orbit for data-analysis, only the inbound segment of the corresponding
M-GITM extraction along MAVEN's trajectory has been included in these files. The M-
GITM output for each orbit has been concatenated on top of each other within this file,
and can be distinguished by the orbit number in the first column. The first row in the
file contains the header, which is composed of all the variable names listed above.

-----------------------------------------------------------------------------------------------------------

Further M-GITM Simulation Details and Notes:

- Model resolution: 5 x 5 degrees (latitude x longitude) in horizontal and 2.5 km in
vertical

- All M-GITM simulations are begun after a 20-day spin-up

- FISM-Mars daily averaged solar EUV-UV flux dataset used in all simulations (a
MAVEN/EUV L3 modeled data product publicly available on the Planetary Data System –
http://doi.org/10.17189/1517691)

- Altitude system in areodetic coordinates

- Dust conditions: constant tau = 0.5 (for visible wavelengths), globally uniform Conrath
parameter of 0.003

- Dynamical ionosphere: off

- Crustal fields: off

- Gravity wave scheme: In cases where it is used, standard parameter values: horizontal
wavelength = 300 km, maximum source momentum flux = 0.0025 m2/s2, 30 wave
harmonics with horizontal phase speeds from -80 to 80 m/s.

References:

Bougher, S. W., Pawlowski, D., Bell, J. M., Nelli, S., McDunn, T., Murphy, J. R., et al.
(2015). Mars Global Ionosphere-Thermosphere Model: Solar cycle, seasonal, and
diurnal variations of the Mars upper atmosphere. Journal of Geophysical Research:
Planets, 120, 311–342. https://doi.org/10.1002/2014JE004715

Medvedev, A. S., Yigit, E., Hartogh, P., & Becker, E. (2011). Influence of gravity waves on
the Martian atmosphere: General circulation modeling. J. Geophys. Res., 116 . doi:
10.1029/2011JE003848

Roeten, K. J., Bougher, S. W., Benna, M., Mahaffy, P. R., Lee, Y., Pawlowski, D., . . . Lopez-
Valverde, M. A. (2019). MAVEN/NGIMS thermospheric neutral wind observations:
Interpretation using the M-GITM general circulation model. Journal of Geophysical
Research: Planets, 124 (12), 3283-3303. doi: https://doi.org/10.1029/2019JE005957

Yigit, E., Aylward, A. D., & Medvedev, A. S. (2008). Parameterization of the effects of
vertically propagating gravity waves for thermosphere general circulation models:
Sensitivity study. Journal of Geophysical Research, 113. doi: 10.1029/2008JD010135

Dataset Citation:

Roeten, K. J., Bougher, S. W. (2022). M-GITM datasets used for a modeling study of the
mean impacts of subgrid-scale gravity waves on thermospheric velocities and
temperatures at Mars [Data set]. University of Michigan Deep Blue Data Repository.