Atmospheric Chemistry

There are three strands to my research in Atmospheric Chemistry. First, we have developed a range of computer models that describe the troposphere (~ lowest 10 km) on urban, regional and global scales and have developed the CRI (Common Representative Intermediates) methodology. The CRI methodology allows us to generate chemical schemes that are compact and traceable back to smog chamber data. Hence we are able to estimate chemical model uncertainty and in addition to generate secondary organic aerosol in a self consistent way for the first time. A particular focus has been the interaction of chemical emissions from terrestrial vegetation and the atmosphere. Using the CRI we have been able to investigate elements of the degradation of isoprene (C₅H₈) in the atmosphere that provide clues about how the OH radical may be recycled efficiently. Such recycling is important in determining greenhouse gas lifetimes in past, present and future climates.

Second, we have developed an inert tracer technique to track air flow both indoors and outdoors, using cyclic perfluorocarbons. This work has allowed us to derive a range of parameterisations to estimate the concentration of a pollutant downwind of either a stationary or moving source as a function of building geometry and wind speed. Recently, we have developed a reactive tracer that allows us to probe the OH field in the urban environment and also indoors. We have also developed instruments based on GC technology to measured very short lived halocarbons that are also implicated in the Earth's climate, where they are believed to be atmospheric coolers.

Third, in collaboration with Dr. Carl Percival and Prof. John Dyke at Manchester Uni. and Drs. Craig Taatjes and Dave Osborn at the Sandia Lab. in SanFrancisco, we have developed a number of novel laboratory systems to measure the kinetics and products of key radical-radical and radical-stable reactions believed to occur in the atmosphere. Most notably, in 2008, we were the first group in the world to observe a Criegee biradical in the gas-phase.

Science Education

My interests are very varied, but I have three main themes. First, the role of context in science education, in particular mathematics. I am interested in a range of generating problems at primary, secondary and tertiary level that generate a desire to investigate and explore science contexts. In mathematics I have explored a number of chemistry contexts that allow mathematical tools to be introduced quite naturally and even students who are fearful or loathing of mathematics can adapt and use these mathematical concepts as tools. Second, I am interested in transitions across the key stages in the UK context and from primary to secondary and from secondary to tertiary, what are the barriers to smooth transition? what are the elements that enhance and augment these transitions? Third, I am interested in understanding how to make public engagement interventions as effective as possible, in terms of cognition, aspiration raising and long term impact.