Drivers of Emerging Transboundary Dust Hazards Across the US-Mexico Border

Abstract

Transboundary dust events have extensive societal impacts and are challenging to address due to differences in land tenure, water rights and use, and their governance across source areas. In Spring 2025, under extreme to exceptional long-term drought, an anomalously large number of dust events formed in the northern Chihuahuan Desert, with a frequency of dust storms in El Paso, Texas not experienced since the 1930s Dust Bowl. Anticipating prolonged drought across the region, there is an urgent need to elucidate the drivers of increased dust activity. As wind and land cover conditions primarily control dust events, we examined 1) how wind conditions were different in Spring 2025 from historical patterns, and 2) recent land cover trends across the northern Chihuahuan Desert that could influence magnitude and frequency of dust events. To this end, we used reanalysis data, remote sensing products, and locally available weather and land cover data to assess spatial and temporal patterns and trends in transport capacity and sediment availability. We identified positive near-surface wind anomalies, conducive to dust mobilization, across the northern Chihuahuan Desert. An intensified subtropical jet stream over the northern Chihuahuan Desert in Spring 2025, due to an anomalously warm Eastern Pacific Ocean offshore of California, resulted in strong upper-level divergence, low-level pressure gradient, and stronger-than-normal near-surface winds. From 2001-2023, agriculture in the Janos and Ascension Municipalities of Chihuahua, and Hidalgo County in New Mexico, expanded by ~3 to 5 times. In the Spring 2025, over 5% of the area had been disturbed and 70% of the disturbed land was barren totaling over 2380 km2. Simultaneously, during 2011-2024, perennial forb and grass cover in the northern Chihuahuan Desert declined while woody cover increased significantly. Exposed land due to the agricultural expansion and declining perennial cover was collocated with the strong winds of Spring 2025, resulting in frequent dust events. Our results provide insights into how agricultural expansion and vegetation changes across the northern Chihuahuan Desert resulted in increased transboundary dust events. Cross-border coordination is needed urgently to mitigate future dust events and associated hazards over downwind communities.