Implementation of the Fast-JX Photolysis scheme into the UKCA component of the MetUM chemistry climate model
1NCAS Climate, University of Cambridge, Cambridge CB2 1EW, UK
2Centre for Atmospheric Science, Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
3Met Office Hadley Centre, Exeter, UK
4National Institute of Water and Atmospheric Research, Lauder, New Zealand
5Institute for Climate and Atmospheric Science, School of Earth and Environment, University of Leeds, UK
Abstract. Atmospheric chemistry is driven by photolytic reactions, making their modelling a crucial component of atmospheric models. We describe the implementation and validation of Fast-JX, a state of the art model of interactive photolysis, into the MetUM chemistry climate model. This allows for interactive photolysis frequencies to be calculated in the troposphere and augments the calculation of the frequencies in the stratosphere by accounting for clouds and aerosols in addition to ozone. In order to demonstrate the effectiveness of this new photolysis scheme we employ new methods of validating the model, including techniques for sampling the model to compare to flight track and satellite data.