The interactive simulation of Mars dust storms with the Mars
General Circulation Model MarsWRF, at the resolution of 7.5°×9°
(latitude×longitude)
AlShehhi, K.1, Gebhardt, C.1, Young, R. M. B.1,2
1

United Arab Emirates University, National Space Science and Technology Center, Al Ain,
United Arab Emirates
2

United Arab Emirates University, College of Science, Department of Physics, Al Ain,
United Arab Emirates

This presentation adds to recent
interactive dust cycle simulations by the
MarsWRF
model
at
horizontal
resolutions of 2°×2° and 5°×5°
(latitude×longitude) [1,2]. The latter are
repeated here at the classical resolution
of 7.5°×9° (latitude×longitude). More
information on the model resolution of
7.5°×9° can be found in Toigo et
al.(2012) [3]. Our results for 7.5°×9° are
compared with higher resolution of
5°×5° simulations by Gebhardt et al.
(2020), JGR Planets [1]. Of particular
interest are dust storms and surface
dust lifting characteristics.

schemes. These schemes account for
surface dust lifting by dust devils and
surface wind stress. Dust devils are
convective vortices which form when
air, heated by the ground, rises. This is
illustrated in Figure 1. The other model
scheme is for surface wind stress which

The
interactive-dust-lifting-technique
means that the MarsWRF model runs
without being constrained by any
external data on the Mars dust cycle.
The model allows the model user to
specify different parameters to simulate
Mars dust storms and dust devils. This is
based on two model parametrization

1. AlphaD (αD): dust devil lifting
rate constant (kg J−1)

depends on the wind speed and air density.
The amount of lifted surface dust depends
on the below wind stress lifting threshold
and the wind stress lifting rate constant.
The latter is a constant of proportionality
between the horizontal and vertical flux of
dust, which are shown in Figure 2.

The three parameters are:

2. AlphaN (αN): wind stress lifting
rate constant
3. Tau (τ): wind
threshold (Pa)

stress

lifting

The model is calibrated to produce
global dust storm events in few Martian
Years but not in others. This requires
model calibration by trial and error. A
particular focus of this presentation will
be the formation of global dust storm
events. Figure 3. shows curves of the
MarsWRF predicted global atmospheric
midlevel
temperature,
or
T15
temperature, for 20 Martian Years in
the 7.5° × 9° model run.

This modelling approach characterizes
processes such as surface dust loss,
atmospheric dust transport, and
deposition of dust onto the surface,
including regional-to-global dust storms.
Thus, it contributes to the Emirates
Mars Mission (EMM) science objective
on the lower atmosphere, and also the
objective of correlating the lower and
upper atmosphere [4,5].

Figure 1. Surface Dust lifting by dust
devils

Figure 2 . Surface Dust lifting by wind
stress.

Figure 3. MarsWRF predicted curves
of the global T15 temperature for the
7.5° × 9° model run

Acknowledgements
This work was supported by a Joint Research Agreement between the Mohammed Bin
Rashid Space Centre (MBRSC) and the National Space Science and Technology Center
(NSSTC), UAE University (UAEU). It was also supported by a MSc scholarship from
NSSTC, UAEU. We thank the PlanetWRF development team for providing the MarsWRF
model free of charge to us. Our particular thanks goes to Dr. Claire Newman and other
model developers based at Aeolis Research, USA (https://aeolisresearch.com/).
References
[1] Gebhardt, C., Abuelgasim, A., Fonseca, R. M., Martín-Torres, J., & Zorzano, M.-P.
(2020). Fully interactive and refined resolution simulations of the Martian dust cycle by
the MarsWRF model. Journal of Geophysical Research: Planets, 125, e2019JE006253.
https://doi.org/10.1029/2019JE006253
[2] Gebhardt, C., Abuelgasim, A., Fonseca, R. M., Martín-Torres, J., & Zorzano, M.P. (2021). Characterizing dust-radiation feedback and refining the horizontal resolution of
the MarsWRF model down to 0.5 degree. Journal of Geophysical Research: Planets, 126,
e2020JE006672. https://doi.org/10.1029/2020JE006672

[3] Toigo, A. D., Lee, C., Newman, C. E., & Richardson, M. I. (2012). The impact of

resolution on the dynamics of the Martian global atmosphere: Varying resolution
studies
with
the
MarsWRF
GCM.
Icarus,
221(1),
276–
288.
https://doi.org/10.1016/j.icarus.2012.07.020
[4] Amiri, H.E.S., Brain, D., Sharaf, O. et al. The Emirates Mars Mission. Space Sci
Rev 218, 4 (2022). https://doi.org/10.1007/s11214-021-00868-x
[5] Almatroushi, H., AlMazmi, H., AlMheiri, N. et al. Emirates Mars Mission
Characterization of Mars Atmosphere Dynamics and Processes. Space Sci Rev 217, 89
(2021). https://doi.org/10.1007/s11214-021-00851-6