Integrating model chemical mechanisms with reaction kinetics databases

The role of chemistry in atmospheric modelling is central to research into climate change and air quality. The description of chemistry in these models, known as the 'chemical mechanism', is becoming increasingly complex as we understand more of the processes and chemical species that are important and need to be included. The validity of such chemical mechanisms relies largely on fundamental laboratory measurements of the kinetics of individual chemical reactions. For many years, expert scientists have evaluated published kinetic data and made it available in peer-reviewed literature and for the last 10yrs via the World-Wide-Web (see the IUPAC database at http://www.iupac-kinetic.ch.cam.ac.uk/). Keeping up to date with the latest laboratory measurements of kinetic reaction data is a time-consuming and error prone task for the atmospheric modelling community. Any changes to the mechanism need to be carefully checked and assessed to understand any differences in the results produced by the model. Consequently, it is not unusual for the kinetic data in complex models of the chemical atmospheric to be out of date. The proposed research seeks to begin development of a facility that would make significant improvements to the way in which the atmospheric chemical modelling community update their chemical mechanisms. It would also increase linkage between kinetic databases and end users, and increase their value to the academic, public and private sectors, particularly where users have limited chemical expertise. To achieve this, an important first step is to be able to describe a model's chemical mechanism in a concise but accurate way that a kinetic reaction database can understand. To this end we will exploit outcome from a recently funded NERC Knowledge Transfer project and define a syntax or 'language' based on XML (eXtensible Markup Language - a generic way of describing data or events). This novel approach will allow a chemical mechanism to be uploaded to the database, analyzed and updated. This will remove the possibility of manual typing errors and significantly speed up the process of updating a model's chemical mechanism. This project will begin development of software to show this concept is viable. In principle, by using a common XML schema between atmospheric models and kinetic reaction databases much more analysis of a chemical mechanism could be done e.g. new components of the reaction scheme could be suggested based on new laboratory measurements, but this is outside the scope of this proposal.