Dr Daniel Stone

Research interests

My research focuses on the study of oxidation processes in atmospheric and combustion chemistry. In particular, my interests lie in the chemistry of reactive species such as OH, HO₂ and Criegee intermediates (R₂COO) that control atmospheric composition and fuel combustion, requiring a combination of laboratory experiments, field measurements and numerical modelling.

Recent laboratory experiments to investigate the kinetics of the CH₂OO Criegee intermediate have provided the first direct measurements of CH₂OO reaction kinetics as a function of pressure, obtained by monitoring the HCHO reaction products by laser-induced fluorescence (LIF) spectroscopy (Stone et al., 2014). This work also have indicated significant yields of CH₂OO following photolysis of CH₂I₂ in the presence of O₂ under atmospheric conditions (Stone et al., 2013), with impacts on our understanding of oxidation chemistry in iodine-rich coastal regions.

Future work will involve the development of a quantum cascade laser (QCL) infrared absorption experiment to monitor Criegee intermediates directly under atmospheric conditions, and to monitor the production of SO₃ in reactions of Criegee intermediates with SO₂. These experiments will enable assessment of the atmospheric impacts of Criegee chemistry on production of sulfuric acid and sulfate aerosol, and thus on air quality and climate change.

I have also participated in several field campaigns to measure OH, HO₂ and OH reactivity in the atmosphere, and was involved in the Clean air for London (ClearfLo) campaign to monitor atmospheric composition during the London 2012 Olympics. My investigation of nighttime aircraft measurements using numerical models of atmospheric chemistry has shown that nighttime oxidation chemistry over the UK is more important than previously expected, and indicates that models currently used to assess air quality and climate change will underestimate atmospheric oxidation rates (Stone et al., 2014). Analysis of data obtained over Borneo (Stone et al., 2011) and West Africa (Stone et al., 2010) has demonstrated significant problems with our understanding of isoprene oxidation chemistry, with important consequences for climate modelling.

Research groups and institutes

• Atmospheric and Planetary Chemistry

Projects

<li><a href="//phd.leeds.ac.uk/project/1408-real-time-gas-sensing-using-terahertz-quantum-cascade-lasers">Real-time gas sensing using terahertz quantum-cascade lasers</a></li>