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The above figure shows an example of the excellent comparison between CH3O2 measured using the FAGE methodology (red) with that determined by CRDS (black). The FAGE methodology has been developed at Leeds, whilst the CRDS studies for CH3O2 was developed by Grant Ritchie’s group in Oxford and brought up to Leeds for an intercomparison in…
PhD student Alex Brennan give an oral presentation at the recent AGU conference in New Orleans. Alex’s talk was on the intercomparison with FAGE and CRDS measurements of HO2. The good agreement between these very different methods for monitoring this crucial atmospheric intermediate goes a long way to eliminating the potential for systematic errors in…
Lavinia presented a poster at the prestigious Gordon Research Conference in Atmospheric Chemistry on work taking place on the NERC INFAMOS grant on the development of new methods for RO2 detection and on intercomparisons of FAGE and CRDS based methods for radical analysis. The poster is available in the poster section of the HIRAC site…
Charlotte successfully defended her thesis (external examiner, Prof Paul Monks from Leicester) during the summer and graduated in full regalia in December 2017. Charlotte is enjoying her new job at the Department of Health as an Operational Research Analyst, using some of the statistical skills developed during her PhD work using Monte Carlo methods to…
2017 has seen the publication of two papers from the HIRAC group looking at instrument development. The first paper describes a new method for detection of the CH3O2 radical. The sensitivity is excellent for kinetic measurements in HIRAC and with some modifications could be the basis of a field instrument. The second paper reports results…
HIRAC was well represented at the GK symposium held in York with posters on OH reactivity/butanol oxidation (Charlotte), ether oxidation (Diogo and Iusti), isoprene oxidation (Iusti) and CH3O2 detection (Lavinia and Alex).
A paper on the development of the OH reactivity instrument has been published in AMT. Charlotte Brumby worked on coupling HIRAC and the reactivity instrument and has more recently been looking at the changes in OH reactivity during butanol oxidation.
Using techniques analogous to those for HO2 detection in FAGE, we have measured CH3O2 in HIRAC by conversion of CH3O2 to CH3O and detection of the latter by LIF. We can obtain good kinetics and the detection limits may allow for the technique to be deployed in the field.
Early in 2016 our definitive publication on the OH yields from the above reaction was published in ACP. Carried out in conjunction with Terry Dillon and Matt Evans, this study provides the first simulaneous observations of all the product channels from this reaction which can contribute to OH recycling.
Alex Brennan joins the group to work on CH3O2 detection. Supervised by Dwayne and Paul, and working with Lavinia, Alex will be developing the CH3O2 detection and working with Rob on implementing ROx-LIF detection in HIRAC.