Deviations from the O3-NO-NO2 photo-stationary state in Delhi, India

Chate, Dilip M., Ghude, Sachin D., Beig, Gurfan, Mahajan, Anoop S., Jena, Chinmay, Srinivas, Reka ORCID:, Dahiya, Anita and Kumar, Nandini (2014) Deviations from the O3-NO-NO2 photo-stationary state in Delhi, India. Atmospheric Environment, 96. pp. 353-358. ISSN 1352-2310

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A network of air quality and weather monitoring stations was set-up across Delhi, India, under the System of Air quality Forecasting And Research (SAFAR) project. The objective of this network was to enable better understanding of air quality in terms of atmospheric chemistry, emissions and forecasting in Delhi, one of the largest metropolises in the world. In this study, we focus on the O3-NO-NO2-triad Photo Stationary State (PSS), and investigate site-specific deviations in the Leighton Ratio (Φ) during a short period in 2012 (1-31 December). Large variations were observed in the NO (<1ppbv to a peak of 295ppbv), NO2 (<2ppbv-47ppbv) and O3 (4ppbv-95ppbv) mixing ratios, all of which showed strong diurnal variation. The Φ values showed large deviations from unity over the measurement period, with mostly negative deviations (Φ<1), showing that the air masses were dominated by local sources of NOx and that the PSS was not achieved. Positive deviations (Φ>1) were also observed occasionally, and these data were used to estimate the total peroxy radical (PO2) mixing ratios. This is the first estimate of PO2 reported for the city of Delhi and compares well with the results in the literature.

Item Type: Article
Additional Information: Funding Information: Indian Institute of Tropical Meteorology, Pune is supported by the Ministry of Earth Sciences (MoES), Government of India, New Delhi. Authors acknowledge the support of Prof. B. N. Goswami, Director IITM Pune. Authors appreciate the efforts of entire team involved in SAFAR project under the MoES.
Uncontrolled Keywords: leighton ratio,nitrogen oxides,ozone,photo-stationary state,safar,environmental science(all),atmospheric science,sdg 11 - sustainable cities and communities ,/dk/atira/pure/subjectarea/asjc/2300
Faculty \ School: Faculty of Science > School of Environmental Sciences
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Depositing User: LivePure Connector
Date Deposited: 04 Nov 2022 09:30
Last Modified: 27 Oct 2023 02:14
DOI: 10.1016/j.atmosenv.2014.07.054

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