Year: 2026
Type: article
Abstract: Post-winter haze events in Delhi, India, comprise great air quality challenges, yet remain poorly understood due to limited measurements of vertical profiles of particulate matter (PM) concentrations. This study employs a drone-mounted PM low-cost sensor (PM-LCS) with an optimized sampling system to capture vertical PM 2.5 profiles during March 2021. Elevated PM 2.5 concentrations (160 µg/m 3 ) were observed at an altitude of 100 m, being 60% higher than ground level. Vertical profiles of the PM 1 /PM 2.5 ratio under humid conditions (RH > 70%), showed that haze formation is likely driven by hygroscopic inorganic aerosols. Comparison with model simulations showed significant underestimation of PM 2.5 (−52.6 ± 5.5%) during morning haze episodes, coinciding with a dry bias in modeled RH (−30.1 ± 8.3%). During non-hazy episodes, PM 2.5 underestimation decreased to 10.8 ± 1.2% with a minimal RH bias. This suggests that the dry bias of the model limits its ability to simulate aerosol hygroscopic growth. Overall, our findings demonstrate that drone-mounted PM-LCS provides a valuable vertical air quality assessment tool.
Source: npj Clean Air
Authors: Ajit Ahlawat, Kajal Julaha, Pravash Tiwari, Shravan Deshmukh, Samira Atabakhsh, Sherin Hassan Bran, Nisar Ali Baig, Palak Balyan, Anil Kumar Mandariya, Dilip Ganguly, Kostas Karatzas, Mayank Kumar, Vikram Singh, Ravindra Khaiwal, Prashant Kumar, George Biskos, Yele Sun, Birgit Wehner, Sagnik Dey, Mira Pöhlker
Institutions: Leibniz Institute for Tropospheric Research, Delft University of Technology, Czech Academy of Sciences, Charles University, Czech Academy of Sciences, Institute of Chemical Process Fundamentals, China University of Mining and Technology, National Astronomical Research Institute of Thailand, Indian Institute of Technology Delhi, Centre National de la Recherche Scientifique, Université Paris-Est Créteil, Université Paris Cité, Laboratoire Interuniversitaire des Systèmes Atmosphériques, Aristotle University of Thessaloniki, Post Graduate Institute of Medical Education and Research, University of Surrey, Cyprus Institute, Chinese Academy of Sciences, Institute of Atmospheric Physics, Korea University, Leipzig University
Language: English
Subfield: Environmental Engineering
Field: Environmental Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $2,590
OpenAlex ID: W7127174930