The analysis of pre-monsoon dust storm over Delhi using ground-based observations

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 airport, New Delhi, India. The results show that after each dust activity, the significant inclusion of dust aerosols loaded in the free troposphere. 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 the first dust storm (DS1), which pinpoints the sudden dust intrusion over NCR, Delhi. However, this dust storm has extensively impacted on the atmospheric vertical dust loading, surface boundary layer mechanisms, and socioeconomic way. Therefore, the detailed analysis of vertical dust distribution and its interaction with mid-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 h 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.