After completing my Ph.D in 1986, I began my postdoctoral research in the Atmospheric and Oceanic Sciences group at Princeton University, working on the use of natural radionuclides and metals as tracers of the oceanic particle cycle. I continued this research as a Senior Scientific Officer at the Plymouth Marine Laboratory in the U.K. During my 3 years in Plymouth, I continued to work on the chemical thermodynamics of electrolytes, and in 1990 returned to the University of East Anglia to work on a new system of equations to model the chemical thermodynamics of aqueous solutions to the high concentrations found in atmospheric aerosols. I collaborated closely on this with the late Kenneth Pitzer of U.C. Berkeley. The first practical application of these equations was a demonstration that some types of polar stratospheric cloud (on which ozone depletion reactions occur) could be liquid rather than solid. This work was carried out in collaboration with the research group of Paul Crutzen at the Max Planck Institute in Mainz.

In 1993, I succeeded in winning the first of two consecutive 5 year Advanced Research Fellowships from the Natural Environment Research Council. These awards have allowed me to apply the chemical models I had developed to both stratospheric and tropospheric aerosols problems, to continue to advance understanding of the fundamental thermodynamics of the components of natural waters by measurement and in critical reviews of existing data, and to make available the chemical models I have developed for both research and teaching.

In 1998, I was appointed to the position of Reader in the School of Environmental Sciences. The following year I began a series of international collaborations in order to extend my research in atmospheric aerosol thermodynamics to include the organic components of aerosols. These began with projects at the Oak Ridge National Laboratory, and Electric Power Research Institute (Palo Alto), which have led to current studies with the U.S. Environmental Protection Agency and the California Institute of Technology aimed at improving regional scale air quality models. 

I became a Professor in 2007, and also have an appointment at the University of California at Davis, where I have a number of collaborative projects in the Air Quality Research Centre.

PhD Positions

Click here for current PhD opportunities in the School of Environmental Sciences. However, feel free to email me to discuss projects outside these areas and alternative sources of funding.


  • 1986-1987 Postdoctoral Researcher at Princeton University, USA.
  • 1987-1990 Senior Scientific Officer at the Plymouth Marine Laboratory, U.K.
  • 1990-1993 Leverhulme Trust Fellow, University of East Anglia
  • 1993-2003 NERC Advanced Research Fellow, University of East Anglia
  • 1998-2007 Reader, School of Environmental Sciences, Univesity of East Anglia
  • (2009-present Professional Researcher in the Air Quality Research Centre at the University of California, Davis)

View graph of relations

ID: 43269