Developing a new modelling tool to measure air quality in the UK

The Community Multiscale Air Quality model (CMAQ) is an open-source air quality management tool developed by the United States Environmental Protection Agency (USEPA). It simultaneously models multiple air pollutants, including ozone and particulate matter, to help regulators determine the best air quality management approaches for their towns, cities and countries. Ricardo Energy & Environment has been appointed by the United Kingdom Department for Environment, Food and Rural Affairs (Defra) to investigate the potential of using CMAQ in the UK.


CMAQ is one of the world’s most sophisticated air pollution models, incorporating state-of-the-art science and numerical modelling techniques involving complex interactions between emissions, meteorology, dispersion and atmospheric chemistry. A major challenge is that CMAQ has not been approved for UK policy applications. A consortium led by Ricardo Energy & Environment is evaluating how CMAQ might meet Defra’s needs, including compliance with air quality reporting to the European Union and quantifying the effects of policies aimed at reducing emissions and improving air quality nationally.


The project is being carried out in two phases. The first, which began in September 2011, has used Ricardo Energy & Environment’s world-leading expertise in air quality modelling to identify and assess to what extent CMAQ could meet UK policy needs and a provisional UK configuration of the model, CMAQ-UK, has been developed. Phase 2 involves modelling concentrations of PM2.5, NO2, O3 and other key pollutants in the UK for the years for 2009 – 2011 and 2019 – 2021 to test CMAQ-UK’s potential for air quality reporting and future scenario analysis 


Ricardo Energy & Environment has successfully provided detailed technical reports and recommendations for Defra and circulated these for peer review by other modelling experts. The demonstration pollutant modelling activities in Phase 2 will take forward the lessons learned during the initial assessment of CMAQ’s applicability to the UK.