Professor David Waltham (Department of Earth Sciences, Royal Holloway, University of London)
Dr Becky Welbourn (Rutherford-Appleton Laboratory)
The atmosphere of the Earth is an oxidizing medium and effectively acts as a low temperature, dilute fuel, combustion system, oxidizing complex compounds and returning them to the surface of the Earth via cloud water and dry deposition. The chemical composition of particulate matter affects climate directly, by scattering and absorbing solar radiation, and indirectly, owing to its ability to act as cloud condensation nuclei, leading to a change in cloud formation rainfall patterns. Cloud processing of atmospheric particulate matter changes the optical properties of clouds.
Atmospheric mineral particulate matter contains organic films that effect the reactivity of the particle and its potential to act as cloud condensation nuclei. You will study the optical properties and kinetics of atmospheric oxidants reacting with organic films on mineral aerosol. The kinetics will give an atmospheric lifetime and optical properties will enable calculation of the change in climatic radiative forcing. If the lifetime is less than ten days and more than 1 minute then it is important.
You will be partly based at the enviable facilities of the Rutherford-Appleton laboratory (Oxfordshire) and undertake experiments at the ISIS neutron source and central laser facility with supervisors currently working with RHUL candidates. You will extract organic material from atmospheric aerosol, place it on silica, alumina and rutile and subject it to atmospheric oxidation. Neutron reflection studies will determine the morphology and thickness of the organic material allowing an assessment of its atmospheric lifetime. Laser tweezer studies will determine the refractive index of the material during oxidation allowing the estimation of a change in radiative forcing of the oxidation.
You will train in bleeding-edge facility techniques to study the interface between minerals and water. The Rutherford-Appleton Laboratory will allow you to interact with many world-leading scientists. You will be trained in laser spectroscopy, neutron reflection, chemical extraction, atmospheric sampling and atmospheric modelling achieving a PhD with modelling, field and laboratory components.
Candidates with degrees in Chemistry, Physics, Engineering or Earth science are encouraged to apply.