Observational and modelling studies of atmospheric structure and photochemistry.
Ozone in the stratosphere protects the biosphere from potentially damaging short wavelength solar radiation. Tropospheric ozone initiates many of the chemical processes, which are necessary for the removal of many pollutant gases, while direct exposure can damage animals and plants. Many other gases play important roles: bromine and chlorine oxides are known to play important roles in stratospheric ozone loss, while gases such as NO3 are important in the nighttime chemistry in both the stratosphere and troposphere. Other gases, such as the ubiquitous water vapour play important roles in both chemistry and climate. However, not only are the basic distributions of many of these gases poorly known, but also their detailed roles in the atmospheric system have yet to be tested adequately - studies of these are the focus of the group.
Widely differing measurement methods are used, together with numerical models for these studies. UV, visible and infra-red spectroscopy, coupled to novel laser and detector technologies, is used to study, amongst other things, atmospheric composition and structure in the upper atmosphere (using the new UK research aircraft and a powerful LIDAR and balloon borne instruments, and the marine planetary boundary layer in Mace Head, Ireland where a novel technique (broad-band cavity ring-down spectroscopy) has been used to explore marine chemistry and oceanic emissions. There are numerous developments of these techniques, e.g. super-continuum light sources to produce compact ultra broadband CRDS systems.
At the other end of the instrument size spectrum is the development of lightweight sensors for O3, CO, CO2, NOx, H2O and hydrocarbons which are being used to study the chemistry of volcanic emissions (e.g. Mt. Etna, the composition of the upper atmosphere and for sensor networks for studying real time personal exposure to gases and aerosols in the urban environment for atmospheric science and health.
Solar driven nitrous acid formation on building material surfaces containing titanium dioxide: A concern for air quality in urban areas?, Atmospheric Environment, doi:10.1016/j.atmosenv.2009.06.046 (2009),
Cavity enhanced absorption spectroscopy of multiple trace gas species using a super- continuum radiation source Optics Express, Vol. 16, Issue 14, pp. 10178-10188, (2008)
An ozone monitoring instrument based on the tungsten trioxide (WO3) semiconductor. Sensors and Actuators, B: Chemical B114(1), 507-512, (2006)
Broad-band cavity ring-down spectroscopy, Chemical Reviews, 103 (12): 5239-5262, Dec (2003)