Beth S Nelson, Daniel J Bryant, Mohammed S Alam, Roberto Sommariva, William J Bloss, Mike J Newland, Will S Drysdale, Adam R Vaughan, W Joe F Acton, C Nicholas Hewitt, Leigh R Crilley, Stefan J Swift, Pete M Edwards, Alastair C Lewis, Ben Langford, Eiko Nemitz, Shivani, Ranu Gadi, Bhola R Gurjar, Dwayne E Heard, Lisa K Whalley, Ülkü A Şahin, David C S Beddows, James R Hopkins, James D Lee, Andrew R Rickard, Jacqueline F Hamilton
Delhi, India, suffers from periods of very poor air quality, but little is known about the chemical production of secondary pollutants in this highly polluted environment. During the postmonsoon period in 2018, extremely high nighttime concentrations of NOx (NO and NO2 ) and volatile organic compounds (VOCs) were observed, with median NOx mixing ratios of ∼200 ppbV (maximum of ∼700 ppbV). A detailed chemical box model constrained to a comprehensive suite of speciated VOC and NOx measurements revealed very low nighttime concentrations of oxidants, NO3 , O3 , and OH, driven by high nighttime NO concentrations...
June 13, 2023: Environmental Science & Technology Letters