The prevailing smog conditions over the Delhi-NCR during the 2022 post monsoon

Abstract

New Delhi experienced worst air-quality days and occurrence of severe smog on 03–04 November 2022. Remote sensing data from various platforms, NOAA HYSPLIT and ERA-5 is utilized to monitor the episode of high smog conditions over Delhi during October- November 2022. It has been observed that AOD has increased up to 4 times till 04 November 2022 when compared to before the starting of burning period. Since the anthropogenic source regions are concentrated around Delhi; the adjoining areas have shown increased burning using fire count data from MODIS Aqua. Study revealed that wind pattern with reduced speeds at lower altitudes is favored to sustain smog for an extended period. The study revealed that the smog over Delhi region for an extended period is formed majorly by the transport of particulate matter and CO emission from nearby areas, compounded by the prevailing fog. Air-mass trajectory analysis confirms that atmosphere over Delhi region was influenced by the transported mass of aerosol particles which corroborated well with the areas characterized by the fire counts, indicating a role of residual burning.