Seasonal and Diurnal Variations of Dust Storms in Martian Year 36 Based on the EMM-EXI Database

The Emirates eXploration Imager (EXI) onboard the Emirates Mars Mission (EMM) is a dual-telescope camera system capable of observing various Martian atmospheric phenomena. The spacecraft's unique orbit allows the EXI to capture full disk views of Mars at a time step of hours or less, with a resolution of ∼2–4 km per pixel (in the nadir-looking direction) in both visible and UV channels. Leveraging these unparalleled observations, we conducted a comprehensive analysis of dust storms for Martian year (MY) 36, in alignment with EMM's scientific goals. This study involved the compilation of a dust storm database covering one MY using EMM-EXI images. This database contains essential information such as the start and end times of dust storms, their areal extent, and the latitude and longitude of the centroid. Furthermore, we devote significant attention to characterizing sub-diurnal variability, a facet not previously emphasized, by meticulously tracking dust storm evolution across multiple local times. Our analysis also delves into the origins, pathways, and morphological attributes of these dust storms. Overall, we catalog a total of 98 dust storms until the end of MY 36 (excluding the polar cap edge dust storms) since the beginning of the EMM science phase, and discuss their diurnal, seasonal, and spatial variability while comparing with some previously published findings. Additionally, we address the potential impact of EMM's coverage on the variability of these dust storms, drawing insights from a well-established multi-year database prepared from the observations of the Mars Color Imager onboard the Mars Reconnaissance Orbiter.