Observations of atmospheric constituents are essential if we are to advance our understanding of the chemistry and radiative properties of the atmosphere. Many reactive atmospheric species exert a profound influence on the chemistry of the atmosphere even at the parts-per-trillion (ppt) level, and detecting these trace species poses a formidable challenge. Our goal in the Venables group is to develop novel approaches for
measuring key atmospheric species and to apply these methods to open questions in
Much of our work has focused on using optical cavities to produce
long effective pathlengths of light through a gas sample. The result is a high sensitivity to small absorptions. In particular, the group is developing and applying broadband optical cavity methods because of their
excellent sensitivity to small absorptions and their suitability for use at visible and ultraviolet wavelengths. This approach achieves comparable sensitivity to long-pass DOAS systems (a cornerstone technique in atmospheric research), but in a much smaller configuration. The resulting high spatial resolution is advantageous for studying short-lived trace gases, the optical properties of aerosols, and for measuring reference spectra of atmospheric molecules. The approach also suited to deployment aboard mobile platforms.
Most recently, the group has focussed on measurements of radical species and on halogen chemistry in field and laboratory studies. These highly reactive species can markedly affect the concentrations of other atmospheric constituents and the overall oxidation capacity of the atmosphere. A further line of investigation is the optical properties of aerosols, particularly at short wavelengths. The influence of aerosols is one of the largest sources of uncertainty in climate research, and such aerosols may also be regionally important in terms of their radiative impact and effect on local photochemistry.
This site describes some of our recent and ongoing research, our group members and collaborators, and the methods that we use. We encourage you to have a closer look at our research and to contact us with any queries.