Investigating dust storm dynamics and lightning interactions using Weather Research Forecasting-Chemistry (WRF-CHEM) model over India.

Dust storms accompanied by lightning are a critical natural hazard that can result in significant loss of life and property. This study employs the Weather Research and Forecasting model coupled with Chemistry (WRF-CHEM) to investigate the interactions between dust storms and lightning over a 48-hour simulation period, using both dust-inclusive and dust-exclusive scenarios over Uttar Pradesh on 23rd May 2022. The WRF model without dust effectively simulated lightning but underestimated its intensity, while the WRF-CHEM model with dust-inclusive simulation captured both lightning intensity and the path and strength of the dust storm. However, it struggled to reproduce the spatial distribution of lightning events accurately. WRF-CHEM predicts over 110 lightning strokes under dust conditions with visibility of 1-2 km, while WRF underpredicts by nearly 60 % due to missing dust electrification; in extreme dust conditions (visibility <1 km), WRF-CHEM simulates 130 strokes, whereas WRF without dust predicts only about 60. The simulated lightning datasets were validated using observations from the WWLLN (World Wide Lightning Location Network) and the IITM Lightning Location Network. Additionally, model-derived parameters such as temperature, relative humidity, and Convective Available Potential Energy (CAPE) were validated against ECMWF ERA5 reanalysis data. The NOAA HYSPLIT model was also utilized to analyze the dynamics, trajectory of the dust storm and corroborate the WRF-CHEM simulations. The WRF-CHEM with dust ON outperformed the WRF without dust. This study highlights the intricate interactions between dust and lightning, contributing valuable insights into predicting thunderstorm and lightning events associated with dust storms, which is crucial for mitigating their adverse impacts.