Atmospheric transport structures shaping the “Godzilla” dust plume

Abstract

Saharan dust events, having great ecological and environmental impacts, are the largest producers of the world’s dust by far. Identifying the mechanisms by which the dust is transported across the Atlantic is crucial for obtaining a complete understanding of these important events. Of these events, the so-called “Godzilla” dust intrusion of June 2020 was the largest and most impactful in the last two decades and underwent a particularly interesting transport pattern. By uncovering dominant, organizing structures derived from the wind velocity fields, known as Lagrangian coherent structures, we demonstrate the ability to describe and qualitatively predict certain aspects related to the evolution of the dust plume as it traverses the atmosphere over the Atlantic. In addition, we identify regions of high hyperbolicity, leading to drastic changes in the shape of the plume and its eventual splitting. While these tools have been quite readily adopted by the oceanographic community, they have still yet to fully take hold in the atmospheric sciences and we aim to highlight some of the advantages over traditional atmospheric transport methods.