School of Chemistry
(Prof. John Dyke)
In this project, electronic structure calculations will be used to perform calculations on key reactions relevant to atmospheric chemistry, climate change and remote sensing.
For example, in the remote marine boundary layer, where contributions from anthropogenic SO2 are small, gas-phase oxidation of DMS is the most important source of oxidized sulphur compounds---notably SO2, methanesulphonic acd (MSA), dimethylsulphoxide (DMSO) and sulphuric acid. Through the production of sulphuric acid, it has been proposed that atmospheric oxidation of DMS may lead to aerosol production and cloud formation, and hence reduction of the solar radiation reaching the earth. This negative feedback to the earth's radiative balance is the basis of the CLAW hypothesis.
In recent studies of the kinetics and mechanism of the reaction of molecular chlorine with DMS by the Southampton group, it has been shown that this reaction could play an important role in DMS oxidation and the interaction between halogens and DMS has to be included in climate studies (see Chemical Physics 324, 2006, 85-95). It is proposed to compute key parts of the potential energy surfaces of selected reactions of atmospheric importance (e.g. DMS + Cl2) in order to elucidate their mechanisms and calculate important values such as the energy released and rate constants. By using these values in a simple atmospheric model, the effect of these reactions on atmospheric chemistry (e.g. on cloud formation) can be understood. This project could also be extended to study ion-molecule reactions and ion-molecule complexes of importance in the upper atmosphere and in remote sensing, and to simulate spectra obtained from reactive intermediates in the earth's atmosphere.
This postgraduate studentship could also involve some experimental work to measure the branching ratios and rate coefficients of selected reactions and the study of selected reaction intermediates of atmospheric importance using a range of photoionization methods coupled to a flow-tube with mass spectrometry and photoelectron spectroscopy.
Applications for this postgraduate position should have, or be expected to have, a first or second class honours degree.
Application details can be obtained from Mrs Chun Borodzicz, cb10@soton.ac.uk
Click here for Employer Profile
