DIX Planetary Science Seminar

Mars has been a source of wonder among planetary and atmospheric scientists since the first global dust storm was observed over a century ago. Since the late 1990s, a fleet of satellites has documented surface conditions from orbit, providing a nearly 20 year-long catalog of daily surface maps. From these maps, the longest and most complete database of dust activity is presented: The Mars Dust Activity Database covers 8 Mars years, documenting 14,974 dust storm instances. Collections of dust storms are organized into sequences if they have a coherent trajectory over three or more days. There are 228 of these sequences, with most originating in the northern hemisphere during winter and spring. Sequences are classified into three main categories based on their growth curves: Main Member, Continuous Development, Sequential Redevelopment, each with distinct characteristics. Separately, "Major" sequences, with a maximum area >107 km2, impact the global opacity, exist over a narrower portion of the Mars year, and travel across hemispheres. Importantly, Major sequences have distinct precursor behavior that may prove valuable for predicting the largest dust events. Finally, the extensive catalog of dust storms has yielded new insights into Martian atmospheric dynamics, including the examination of a new storm track in the southern hemisphere, quantifying the response of the atmosphere to large dust events, and the discovery of annular mode dynamics in the Martian atmosphere.