Regional NO sub(x) emission strength for the Indian subcontinent and the impact of emissions from India and neighboring countries on regional O sub(3) chemistry

• Published in: Journal of Geophysical Research. D. Atmospheres 2006-08, Vol.111 (D15)
• Main Authors: Kunhikrishnan, T, Lawrence, Mark G, Von Kuhlmann, Rolf, Wenig, Mark O, Asman, Willem AH, Richter, Andreas, Burrows, John P
• Format: Article
• Language: English
• ISSN: 0148-0227
• DOI: 10.1029/2005JD006036

This study examines the regional NO sub(x) emission strength and influence of external emissions on O sub(3)-related chemistry over the Indian subcontinent based on a three-dimensional chemistry transport model and space-based observations, following up on our earlier work on NO sub(x) chemistry over southern Asia. NO sub(x) mass and emissions from Global Ozone Monitoring Experiment (GOME) and Model of Atmospheric Transport and Chemistry-Max Planck Institute for Chemistry Version (MATCH-MPIC) over India are compared, and the uncertainties in the estimates are briefly discussed. This study also employs the concept of small-perturbation tendencies to compute the scaled sensitivities with modified NO sub(x) emissions for India and the neighboring continents. The sensitivities of NO sub(x), O sub(3), OH, and reservoir species of NO sub(x) over India to NO sub(x) emission from India, Southeast Asia, Africa, China, and the Middle East are discussed with respect to the photochemistry and the regional meteorology. Our study suggests that the mean regional NO sub(x) emission strength for India is close to 2.5 Tg(N)/yr with a seasonal maximum ( similar to 3 Tg(N)/yr) during April and minimum ( similar to 1.6 Tg(N)/yr) during winter. The changes in the O sub(3) concentrations with respect to NO sub(x) and nonmethane hydrocarbon emissions from India show that southern India is relatively more sensitive to local emission.