Research


1. Biomass burning emissions and implications for radiative forcing

Objectives:

  • Understand the fate of brown carbon (BrC) from biomass burning emissions;
  • Understand ozone formation from biomass burning emissions and its impact on global oxidation capacity;

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:

  • Zak Tourville (PhD student), Ragen Davey (MS student), James Campbell (Undergraduate), and collaborators including Xuan Wang (Harvard), Judy Chow (DRI) and L.-W. Antony Chen (U of Nevada).

Reference:

  • Mao, J., L. W. Horowitz, V. Naik, S. Fan, J. Liu, and A. M. Fiore (2013), Sensitivity of tropospheric oxidants to biomass burning emissions: implications for radiative forcing, Geophys. Res. Lett., 40(6), 1241-1246.
(photo courtesy of Cameron McNaughton)

2. Wintertime aerosol pollution in Fairbanks 

Objectives:

  • Understand multiphase chemistry of TMI in ambient aerosols including sulfate and organics;
  • Understand the role of TMI in global biogeochemical cycling of Fe and Cu;
  • Investigate the adverse health effects of TMI in ambient aerosols.

Approach:

  • Use field observations and models to examine possible TMI chemistry in ambient aerosols;
  • Measure soluble Fe and Cu in ambient aerosols.

People:

  • Ragen Davey (MS student),James Campbell (Undergraduate), and collaborators including Bill Simpson (UAF) and Rodney Weber (Georgia Tech).

Funding:

  • Alaska Space Grant, UAF BLaST Pilot Project.

Reference:

  • Mao J., Fan, S., Jacob, D. J., and Travis, K. R.: Radical loss in the atmosphere from Cu-Fe redox coupling in aerosols, Atmos. Chem. Phys.,  13, 509-519, doi:10.5194/acp-13-509-2013, 2013 (link).
  • Mao, J., Fan, S., and Horowitz, L. W.: Soluble Fe in Aerosols Sustained by Gaseous HO2 Uptake, Environmental Science & Technology Letters, 4, 98-104, 10.1021/acs.estlett.7b00017, 2017. (link)

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:

  • 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, accepted.
  • 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.
  • J. Mao, F. Paulot, D.J. Jacob, R.C. Cohen, J.D. Crounse, P.O. Wennberg, C.A. Keller, R.C. Hudman, M.P. Barkley, and L.W. Horowitz : Ozone and organic nitrates over the eastern United States: sensitivity to isoprene chemistry, J. Geophys. Res., 118(19), 11,256–11,268.

4. Chemical fingerprint of Arctic greening

Objectives:

  • Provide ground validation of satellite HCHO observations at high latitudes
  • Understand trend of BVOC emissions in Arctic as a result of Arctic greening
  • Determine the major drivers of BVOC emission trend in Arctic and its possible impact on atmospheric composition

Approach:

  • Use Pandora, MAXDOAS, and satellite observations to evaluate HCHO variability in Arctic
  • Use ground, satellite and global models to determine BVOC emissions and long-term trends
  • Use global models to determine the impact of Arctic greening on atmospheric composition

People:

  • Sujai Banerji (PhD student), and collaborators including Bill Simpson (UAF), Bob Swap (NASA GSFC), Gonzalo Gonzalez Abad (Harvard CFA),

    Caroline R Nowlan(Harvard CFA).

Funding:

  • NASA EPSCoR program