Investigating dust electrification in arid environments using sea breeze systems

Electrification influences the behaviour of airborne dust by altering how long particles remain suspended, aggregate, and interact with surfaces. This study investigates how wind-driven dusty processes modulate the near-surface electric potential gradient (PG) using data from sea breeze events. It examines how dust-influenced PG observations vary with wind speed, dust concentration, and turbulence at an inland desert site in Al Ain, United Arab Emirates. 129 sea breeze events were analysed using PG measurements, ceilometer backscatter, visibility sensors, surface PM 10 and PM 2.5 (particulate matter) concentrations, and meteorological observations. Sea breezes, coincident with increased dust concentrations, consistently cause a sharp increase in PG up to 6 kV m −1 . Visibility drops to around 5 km as wind speeds exceed the 6 m s −1 threshold for dust lofting, and PM values increase to concerning levels. In contrast, land breezes are characterised by wind speeds less than the threshold, increased visibility, and low PG values not exceeding 150 V m −1 , indicating limited dust uplift. Backscatter vertical profiles show that sea breezes lift particles to heights of up to ~800 m, whilst in contrast, land breezes clear the air. Further, we report that turbulence at the advancing sea breeze front modulates the dust electrification, with oscillations in the dust-layer height closely tracking PG variability. Shear instabilities, including Kelvin–Helmholtz billows, transfer charge and enhance vertical dust mixing and charge separation above the surface. The repeatability of dust electrification by sea breezes reveals further contributions to electrification from local turbulence.