Dust in motion: Spatiotemporal variability and climatic drivers of global surface dust concentration (1980–2023)

Surface mineral dust reflects interactions among persistent source environments, seasonal circulation, land-surface susceptibility, and large-scale climate variability, with pronounced regional differences. We examined MERRA-2 near-surface dust mass concentration across eight major dust-source regions during 1980–2023. Thirty-two high-concentration hotspots were identified, mainly in desert and dune systems, playas or dried lakebeds, and sparsely vegetated surfaces. Regional mean loading was highest in North Africa, followed by Central Asia and the Middle East, and lowest in North America. Long-term evolution was strongly asynchronous: ten robust trend transitions occurred across five regions, but sensitivity analysis identified the North American transition around 2000 as potentially observing-system-sensitive; North Africa, Australia, and Southern Africa followed more gradual trajectories. Seasonal timing was more persistent, with only three robust transitions in North Africa, East Africa, and North America. Wind-related variability formed the expected dynamical background within MERRA-2, whereas non-wind relationships were region specific. Soil moisture showed the strongest negative association in East Africa ( r = −0.48), while evaporation-related associations had opposite signs in Central Asia and the Middle East versus East Africa. Large-scale climate associations were moderate and geographically selective (maximum | r | = 0.39): Pacific Decadal Oscillation (PDO) associations were concentrated in the Americas, whereas Dipole Mode Index (DMI) and Arctic Oscillation (AO) associations were confined to fewer African and Eurasian regions. Global surface-dust variability is therefore organized into interacting regional regimes rather than a single global trajectory or universal driver hierarchy.