MY34 DUST STORM EFFECT ON MIDDLE ATMOSPHERE WATER
VAPOR AND UPPER ATMOSPHERE HYDROGEN ON MARS USING THE
LMD-GCM
H. A. AlMazmi, UAE Space Agency, Abu Dhabi, UAE (h.almazmi@space.gov.ae), M. S. Chaffin, Laboratory
for Atmospheric and Space Physics, University of Colorado Boulder, CO, USA, E. Millour, Laboratoire de
Météorologie Dynamique, Paris, France, J. Deighan, Laboratory for Atmospheric and Space Physics, University of Colorado Boulder, CO, USA, H. R. Almatroushi, Mohammed Bin Rashid Space Centre, Dubai, UAE, R.
L. Lillis, M. O. Fillingim, Space Sciences Laboratory, University of California, Berkeley, CA, USA, S. L. England, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA, S. K. Jain, G. M. Holsclaw, ,
Laboratory for Atmospheric and Space Physics, University of Colorado Boulder, CO, USA, F. H. Lootah, Mohammed Bin Rashid Space Centre, Dubai, UAE, F. Forget, Laboratoire de Météorologie Dynamique, Paris,
France

Introduction:
Variations in Hydrogen escape at different seasons that could be attributed to water vapor variations in the middle atmosphere as stated by Chaffin
et al. (2017) [1]. Water vapor is also seen to increase
by an order of magnitude in the middle atmosphere
due to dust storms [2]. This in turn results in an increase in Hydrogen escape due to dust storms as observed by Mars Climate Sounder Data [3]. The proper understanding of how dust storms affect the rise of
water vapor in altitude that in turn enhances hydrogen escape is studied.
Motivated by the Emirates Mars Mission’s Objective of correlating the escape rates between the
upper and lower atmosphere of Mars, this paper aims
to provide theoretical expectations for the effect of
dust storms on the escape of Hydrogen in the upper
atmosphere [4].
The Laboratoire de Météorologie Dynamique
(LMD) 3D Global Climate Model (GCM) of the
Martian atmosphere provides different scenarios of
dust distributions including reconstructions of dust
storms on mars during various Mars years based on
available observations [5][6].
In order to observe the effect of dust storms on
the atmosphere, we use GCM outputs of the Mars
Year 34 (MY34) dust event and compare it to the
cold scenario of the GCM which shows the minimum
amount of dust observed on the planet.

scenarios. The streamfunction of the two scenarios
are also compared in order to look at how the atmospheric flows is affected. We also look at the water
ice cloud changes in the GCM output during the dust
storms.
Results:
We notice an increase in water vapor during the
dust storms of MY34 in the LMD-GCM outputs that
is not seen in the cold case scenario. We also see an
increase in the streamfunction during the storm that
is more than what is seen in the cold case scenario.
We compare the water ice clouds to look at the differences between the two scenarios.
a

b

c

Methodology:
We use the outputs provided by LMD of the entire year for the two scenarios, MY34 and cold. We
compare the mixing ratios of the dust, water vapor,
and hydrogen at their relevant pressure levels in order to observe the changes that occur with the different dust storm intensities throughout the year. The
three plots (Figure 1, 2, and 3) are showing the mean
mixing ratios over the labeled pressure ranges. The
water vapor pressure is chosen to represent 50 km100 km, and the hydrogen pressure range is based on
the exobase. We also differentiate between seasonal
effects and dust storm effects by comparing the two

Figure 1: Dust mixing ratio for MY34 and the
cold case and their difference

a

b

c

Figure 2: Water vapor mixing ratio for MY34
and the cold case and their difference
a

b

c

Figure 3: Hydrogen mixing ratio for MY34 and
the cold case and their difference
References:
[1] Chaffin, M., Deighan, J., Schneider, N.,
Stewart, A. (2017). Elevated atmospheric escape of
atomic hydrogen from Mars induced by high altitude
water. Nature Geoscience,10(3), 174178.
doi:10.1038/ngeo2887.
[2] Fedorova, A., Bertaux, J., Betsis, D., Montmessin, F., Korablev, O., Maltagliati, L., Clarke, J.
(2018). Water vapor in the middle atmosphere of
Mars during the 2007 global dust storm. Icarus,300,
440457. doi:10.1016/j.icarus.2017.09.025
[3] Heavens, N. G., Kleinb¨ohl, A., Chaffin, M.
S., Halekas, J. S., Kass, D. M., Hayne, P. O., . . .
Schofield, J. T. (2018). Hydrogen escape from Mars

enhanced by deep convection in dust storms. Nature
Astronomy,2(2), 126132.
doi:10.1038/s4155001703534
[4] Amiri, H. H. S., Brain, D., Sharaf, O., Withnell, P., McGrath, M., Alloghani, M., … others
(2022). The emirates mars mission. Space Science
Reviews, 218 (1),1–46.
[5] Millour, E., Forget, F. (2014). User manual
for the lmd martian atmospheric general circulation
model.
https://trac.lmd.jussieu.fr/Planeto/browser/trunk/LM
DZ.MARS/user_manual.pdf
[6] González-Galindo, F., López-Valverde, M.
A., Forget, F., García-Comas, M., Millour, E. and
Montabone, L. (2015). Variability of the Martian
thermosphere during eight Martian years as simulated by a ground-to-exosphere global circulation model. Journal of Geophysical Research (Planets),
vol.120, pp.2020