Unraveling the short-duration Delhi dust storm: insights from In-Situ, satellite, and reanalysis datasets

Abstract

Short-lived dust storms (DS) pose significant challenges due to their sudden onset, rapid intensification, and severe impacts on air quality, visibility, transportation, and public health. Unlike long-duration dust storms, these short-duration events remain poorly understood, largely because of limitations in observations and forecasting capabilities. The dust storm that occurred over Delhi on 11 April 2025 provides a valuable case to examine the meteorological processes driving such rapid-onset events. ERA5 fields reveal the presence of a low-pressure system over northwest India, accompanied by strong westerly surface winds exceeding 12 m s⁻¹, which facilitated dust transport from nearby arid regions. Radiosonde derived convective available potential energy shows a sharp increase (~ 2300 J kg⁻¹) on the dust storm day, compared to ~ 700 J kg⁻¹ on the preceding day, indicating a highly unstable atmosphere conducive to deep convection and dust uplift. HYSPLIT back-trajectory analysis further confirms the dust transport from source regions. AERONET and satellite observations show enhanced aerosol loading, with aerosol optical depth peaking at ~ 0.73 and 0.6 during the event, respectively. An abrupt rise in PM₁₀ and PM₂.₅ concentrations is noticed ~ 950 µg m⁻³ and ~ 200 µg m⁻³, respectively, highlighting the dominance of coarse-mode dust aerosols. This abundance of dust aerosols reduced visibility from ~ 3500 m to ~ 500 m and led to a surface cooling of ~ 3 °C due to reduced incoming solar radiation. The results highlight the urgent need to strengthen short-range forecasting of rapid-onset DS by integrating high-frequency observations and improving dust parameterizations, thereby enhancing public health preparedness, aviation safety, and urban resilience.