1. Carbonaceous aerosols from boreal forest fires and implications for radiative forcing 

Objectives:

• Understand  the emission and fate of brown carbon (BrC) and black carbon from boreal forest fires;
• Examine the impact of boreal forest fires on radiative forcing

Approach:

• Measure the optical properties of BrC in the field and lab;
• Use intensive field/satellite observations to evaluate model representation  of brown carbon and ozone;
• Use global climate model to  predict future air pollution influenced by projected biomass burning  emissions.

People:

• Kunal Bali (PhD student), James Campbell (PhD student) and collaborators including L.-W. Antony Chen (U of Nevada) and Judy Chow (DRI).

Funding:

• NSF

Reference:

• Nicole June, Xuan Wang, L.-W. Antony Chen, Judith C. Chow, John G. Watson, Xiaoliang Wang, Barron H. Henderson, Yiqi Zheng, Jingqiu Mao: Spatial and temporal variability of brown carbon in United States: implications for direct radiative effects, Geophysical Research Letters, 47, e2020GL090332. https://doi. org/10.1029/2020GL090332 (link).
• L.-W. Antony Chen, Judith C. Chow, Xiaoliang Wang, Junji Cao, Jingqiu Mao, and John G. Watson: Brownness of Organic Aerosol over the U.S.: Evidences for Seasonal Biomass Burning and Photobleaching Effects, Environ. Sci. Technol. 2021, https://doi.org/10.1021/acs.est.0c08706.

(photo courtesy of  Cameron McNaughton)

3. Anthropogenic influences on biogenic secondary organic aerosol

Objectives:

• Quantify the yields of oxygenated VOCs  from oxidation of biogenic VOCs and their  contribution to aerosols;
• Better understand ozone formation from oxidation of BVOCs under different NOx regimes;
• Evaluate the role of biogenic VOCs in climate system

Approach:

• Use intensive field/satellite observations to evaluate model representation  of BVOC oxidation;
• Use multidecadal  observations to evaluate model representation of ozone and aerosols resulting from emission changes;
• Use global climate model to simulate future air pollution in different future scenarios.

People:

• Yiqi Zheng, and collaborators including Larry Horowitz(GFDL), Vaishali Naik (GFDL), Sally Ng (Georgia Tech), Joel Thornton (U Washington) and Havala Pye (EPA).

Funding:

• NOAA Climate Program Office.

 Reference:

• Zheng, Y., Thornton, J. A., Ng, N. L., Cao, H., Henze, D. K., McDuffie, E. E., Hu, W., Jimenez, J. L., Marais, E. A., Edgerton, E., and Mao, J.: Long-term observational constraints of organic aerosol dependence on inorganic species in the southeast US, Atmos. Chem. Phys. , https://doi.org/10.5194/acp-2020-575, 2020 (link).
• Li., J.  ,  J. Mao, Fiore, A. M., Cohen, R. C., Crounse, J. D., Teng, A. P., Wennberg, P. O., Lee, B. H., Lopez-Hilfiker, F. D., Thornton, J. A., Peischl, J., Pollack, I. B., Ryerson, T. B., Veres, P., Roberts, J. M., Neuman, J. A., Nowak, J. B., Wolfe, G. M., Hanisco, T. F., Fried, A., Singh, H. B., Dibb, J., Paulot, F., and Horowitz, L. W.: Decadal change of summertime reactive nitrogen species and surface ozone over the Southeast United States, Atmos. Chem. Phys., 2018.
• Li., J. ,  J. Mao, R. A. Washenfelder, S. S. Brown , J. Kaiser, F. N. Keutsch, R. Volkamer, G. M. Wolfe and coauthors , Observational constraints on glyoxal production from isoprene oxidation and its contribution to organic aerosol over the Southeastern United States, Journal of Geophysical Research: Atmospheres, 121(16), 9849-9861, doi:10.1002/2016JD025331.

 

4. Chemical fingerprint of Arctic greening