Abstract
Three major sequential widespread dust events were experienced in the northern parts of India in May 2018. A significant impact of these pre-monsoon dust storms on the aerosol characteristics over the Indian National capital region (NCR) has been studied using remotely sensed ceilometer and ground-based measurements at Indira Gandhi International (IGI) airport, New Delhi, India. From the results, it is noticed that after each consecutive dust activity, the significant inclusion of dust aerosols loaded in the Free Troposphere (FT). Consequently, the direct impact on the lower atmospheric parameters like increase in daily average temperature (by 4–5 K), stepped up (stepped down) diurnal cycles of longwave fluxes (shortwave fluxes) has been recorded within 15 days of dust span. Mainly, the adverse meteorological and radiation features noticed before first dust storm (DS1), which pinpoints the sudden intrusion of dust over NCR, Delhi. However, this dust storm has extensively impacted in terms of the vertical dust loading, surface boundary layer mechanisms, and socioeconomic way. Therefore, the detailed analysis of vertical dust distribution and its interaction with middle tropospheric processes has been carried by using the vertical normalized attenuated backscatter coefficients accompanying the radiosonde observation. The aloft floating dust layer up to 3–4 km has been noticed even after shallow rainfall and persisted at almost the same height for the next 34 hrs due to low-level clouds. Meanwhile, the sub dust layer below 1 km is formed due to local activity, which also sustains for a long time. Moreover, the cumulative losses in terms of the impediment in airline operations (delay and diversion), live causalities, and deaths were estimated at US$1.3 million over these dust period.