A dust storm database from the early high-dust-loading season to the beginning
of the solsticial pause based on EMM/EXI images
B. K. Guha1, C. Gebhardt1, R. M. B. Young1, 1National Space Science and Technology Center, UAE University, Al Ain, Abu Dhabi, UAE (bijayguha@uaeu.ac.ae), M. J. Wolff2, 2Space Science Institute, Boulder, CO,
USA.

Abstract:
Emirates eXploration Imager (EXI) onboard
Emirates Mars Mission (EMM) is a multiwavelength double lens camera suitable for observing the Martian lower atmospheric phenomena such
as dust storms. The visible channel is capable of producing full Martian disk (~2-5 km per pixel resolution) images, which we have used in this work to
characterize the dust storms of the current season.
Notably, the dust storm research is directly aligned
with the EMM science objective on the lower atmosphere and also to the objective of correlating the
lower and upper atmosphere [2]. It is worth mentioning EMM orbit with an inclination of 25° enables
EXI to get a local time coverage throughout the longitude range every 9-10 days [1, 4]. This unprecedented observation allows analyzing the dust storm
characteristics with a sub-diurnal time scale, which
has not been well explored. One of such high temporal resolution observations from EXI is given here
as an example (Figure 1).
The high-dust-loading season typically starts near
solar longitude (LS) 180°, which can be marked from
significantly high background opacity [3]. However,
EXI reported the first regional dust event of MY 36
at LS ~152° around the Syrtis Major region. Furthermore, the climatological record of dust storms has a
so-called ‘solsticial pause’ in the local-regional dust
storm occurrence during LS ~230 – 300° [5]. Therefore, we chose the study period from the beginning
of the EMM science phase until LS ~230° of MY 36,
which includes a significant part of the high-dustloading season. In this study, we present a dust storm
database, derived from camera images by the EMM
instrument EXI. This will include the start and end
time of dust storms, their latitude, longitude, and
area. Also, the origination region, pathway, and morphological characteristics of dust storms are relevant.

Acknowledgements:
The authors would like to acknowledge support
by a Joint Research Agreement between the Mohammed Bin Rashid Space Centre and the National
Space Science and Technology Center (NSSTC),
UAE University. It was also supported by the UAE
University grant “Mars and Earth atmospheric science research at the NSSTC”, G00003407.

Figures:

Figure 1. (a) RGB image (the red circle highlights a dust
storm), (b) f546 band image at I/F unit, (c) I/F (magnitudes
are mulitiplied by a factor of 10) showing the area of the
dust storm (using a threshold I/F>0.55).

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[4] Jones, A.R., et al. (2021). Space Science Reviews, 217, 81.
[5] Wang, H., & Richardson, M. I. (2015). Icarus, 251, 112-127.