Impact of COVID-19 lockdown on the ambient air-pollutants over the Arabian Peninsula

Lockdowns imposed across the world to combat spread of COVID-19 pandemic also reduced anthropogenic emissions. This study investigates changes in and natural pollution levels during lockdown over Arabian Peninsula (AP), a region where pollutants (mineral dust) dominate. In-situ satellite observations, reanalysis products, Weather Research Forecasting model (WRF) coupled with Chemistry module (WRF-Chem) simulations were analyzed investigate influence COVID?19 on aerosols (PM 2.5 , PM 10 AOD) trace gases (NO 2 SO ). WRF-Chem reasonably reproduced in-situ measurements period, correlation coefficients varying between 0.6–0.8 (0.3–0.8) for ) at 95% confidence levels. During lockdown, indicate significant reduction (50–60%) gas concentrations entire AP compared pre-lockdown period. is shown be mostly due emissions an increase boundary layer height. An aerosol central northern parts AP, decrease north-west Red Sea, Gulf Aden regions are noticeable lockdown. suggest that particulate mainly dust concentrations, manifested by stronger convergence upliftment winds warmer surface temperatures (15–25%) desert regions. The restricted activities drastically however, concentration offset processes (dust emissions).