Atmospheric chemistry of organic aerosols: Insights from aerosol mass spectrometry

SLP Topic for the IITB-WUStl Joint Masters program 

Collaborators: Prof. Brent Williams, WUStL and Prof. Abhishek Chakraborty, IITB-ESED


Air pollution, especially aerosol/particulate matter (PM) pollution, is a severe issue in India with a large contribution of organic components of fine particles, termed organic aerosols (OA) [1,2]. However, our understanding of OA formation and aging/oxidation mechanisms has still not sufficiently advanced. OA components exert toxic effects, while they also modify cloud structure by acting as condensation nuclei [3,4], thus having effects on human health and climate change. In this work, we will investigate which OA species dominate pollution aerosols over India, collected from a network of sites across India under the COALESCE [5] project. State of the art instruments like Aerosol Mass Spectrometer (AMS) [6,7] will be used to better understand possible sources and underlying reactions that lead to the formation of these species.  Continuing work will include evaluation of oxidation reaction kinetics on key organic source marker molecules using a Potential Aerosol Mass (PAM) oxidation flow reactor [8].  This information can be used to help improve models that predict the formation and aging of atmospheric secondary OA derived from specific pollution source types.

Evaluation: Regular progress presentations during the semester to advisors; report and presentation to an examining committee at the end of the semester.


(1)      Jimenez, J. L.; Canagaratna, M. R.; Donahue, N. M.; Prévôt, A. S. H.; Zhang, Q.; Kroll, J. H.; DeCarlo, P. F.; Allan, J. D.; Coe, H.; Ng, N. L.; et al. Evolution of Organic Aerosols in the Atmosphere. Science 2009, 326 (5959), 1525–1529.

(2)      Zhang, Q.; Jimenez, J. L.; Canagaratna, M. R.; Allan, J. D.; Coe, H.; Ulbrich, I.; Alfarra, M. R.; Takami, A.; Middlebrook, A. M.; Sun, Y. L.; et al. Ubiquity and Dominance of Oxygenated Species in Organic Aerosols in Anthropogenically-Influenced Northern Hemisphere Midlatitudes. Geophys. Res. Lett. 2007, 34 (13).

(3)      Li, H.; Zhang, Q.; Jiang, W.; Collier, S.; Sun, Y.; Zhang, Q.; He, K. Characteristics and Sources of Water-Soluble Organic Aerosol in a Heavily Polluted Environment in Northern China. Sci. Total Environ. 2021, 758, 143970.

(4)      Chan, M. N.; Kreidenweis, S. M.; Chan, C. K. Measurements of the Hygroscopic and Deliquescence Properties of Organic Compounds of Different Solubilities in Water and Their Relationship with Cloud Condensation Nuclei Activities. Environ. Sci. Technol. 2008, 42 (10), 3602–3608.

(5)      Venkataraman, C., M. Bhushan, S. Dey, D. Ganguly, T. Gupta, G. Habib, A. Kesarkar, H. Phuleria, R. Sunder Raman (2020) Indian network project on Carbonaceous Aerosol Emissions, Source Apportionment and Climate Impacts (COALESCE), Bull. Am. Met. Soc.,

(6)      DeCarlo, P. F.; Kimmel, J. R.; Trimborn, A.; Northway, M. J.; Jayne, J. T.; Aiken, A. C.; Gonin, M.; Fuhrer, K.; Horvath, T.; Docherty, K. S.; et al. Field-Deployable, High-Resolution, Time-of-Flight Aerosol Mass Spectrometer. Anal. Chem. 2006, 78, 8281–8289.

(7)      Daellenbach, K. R.; Bozzetti, C.; Křepelová, A.; Canonaco, F.; Wolf, R.; Zotter, P.; Fermo, P.; Crippa, M.; Slowik, J. G.; Sosedova, Y.; et al. Characterization and Source Apportionment of Organic Aerosol Using Offline Aerosol Mass Spectrometry. Atmos. Meas. Tech. 2016, 9 (1), 23–39.

(8)      Kang, E., M.J. Root, D.W. Toohey, and W.H. Brune, Introducing the concept of Potential Aerosol Mass (PAM). Atmospheric Chemistry and Physics, 2007. 7(22): p. 5727-5744. 

UG Project Type
Name of Faculty