University of California, Riverside

Environmental Sciences

Paul J. Ziemann

Paul J. Ziemann

Paul Ziemann Photo

Professor of Atmospheric Chemistry, Emeritus

Academic Degrees:

  • Ph. D., Penn State, 1991


  • Our research involves experimental studies of the chemistry of submicron atmospheric aerosol particles. Particles in this small size range are generally formed by combustion or by a process referred to as gas-to-particle conversion, which is often quite complex and can include photochemical gas-phase reactions, heterogeneous surface chemistry, homogeneous nucleation, and liquid-phase reactions. The resulting particles play important roles in global climate, urban smog formation, visibility, and human health. In our research, we use a thermal desorption particle beam mass spectrometer we developed, in conjunction with standard tools for aerosol sampling and size and composition analysis, such as cascade impactors, differential mobility analysis, and gas chromatography-mass spectrometry, to investigate fundamental processes responsible for gas-to-particle conversion in the atmosphere. In particular, our work is aimed at elucidating the mechanisms by which volatile anthropogenic and biogenic organic compounds are oxidized to form condensable compounds that form particulate material. Information on the products and mechanisms of reactions of gaseous and condensed-phase species, as well as compound thermochemical properties such as vapor pressure are obtained from environmental chamber studies. These tools are also being used in studies of particle formation in combustion systems, such as diesel engines, and for analysis of ambient atmospheric particles. The results of these studies are used to further our understanding of atmospheric aerosol chemistry and the impact of human activities on the atmospheric environment.

Representative Publications:

  • Tobias, H.J., Kooimann, P.M., Docherty, K.S., and P.J. Ziemann. Real-time chemical analysis of organic aerosols using a thermal desorption particle beam mass spectrometer, Aerosol Sci. Technol. 33: 170-190 (2000)
  • Docherty, K.S., W. Wu, Y.B. Lim, and P.J. Ziemann. Contributions of organic peroxides to secondary aerosol formed from reactions of monoterpenes with O3, Environ. Sci. Technol. 39: 4049-4059 (2005)
  • Prenni, A.J., Petters, M.D., Kreidenweis, S.M., DeMott, P.J., and P.J. Ziemann.  Cloud droplet activation of secondary organic aerosol, J. Geophys. Res. 112:D10223 (2007)
  • Matsunaga, A., and P.J. Ziemann.  Yields of beta-hydroxynitrates and dihydroxnitrates in aerosol formed from OH radical-initiated reactions of linear alkenes in the presence of NOx, J. Phys. Chem. A 113: 599-606 (2009)
  • Lim, Y.B., and P.J. Ziemann.  Effects of molecular structure on aerosol yields from OH radical-initiated reactions of linear, branched, and cyclic alkenes in the presence of NO, Environ. Sci. Technol. 43: 2328-2334 (2009)

Honors and Awards

  • 2001 Kenneth T. Whitby Award, American Association for Aerosol Research

More Information

General Campus Information

University of California, Riverside
900 University Ave.
Riverside, CA 92521
Tel: (951) 827-1012

Department Information

Environmental Sciences
Geology 2460

Tel: (951) 827-5116
Fax: (951) 827-4652