Two Near-Identical Dust Storms in Amazonis/Arcadia, Mars, and Nearby Low-Pressure Systems—EMM/EXI Observations Constrain Possible Scenarios

The Emirates Mars Mission carries the Emirates eXploration Imager instrument, which captured hourly images on 15 and 24 September 2024. That is equivalent to Martian Year 37, solar longitude 329° and 335°, respectively. These observations recorded two nearly identical dust storms in the Amazonis/Arcadia region. We analyze the hour-by-hour evolution of both dust storms, using seven to eight unique images each. We track the onset and growth of the dust storms from around 10 through 16 local true solar time. We also analyze nearby water-ice clouds and discuss large-scale meteorological conditions. Both dust storms start in late morning, in or near the warm sector of a low pressure system. There is no evidence that the dust storms form directly on the associated cold front. There are different scenarios how dust storms form and develop. We show a specific scenario for two dust storms.