Data are monthly and annual mean total and components of PM2.5 over the UK in the lowest model layer for comparison to surface concentrations of PM2.5 and assessment of air quality in the UK and in target cities (Leicester, London, Birmingham).

Specifically, these are the PM2.5 mass concentrations  obtained with all natural and anthropogenic sources (appended as _all-sources.nc). These include total PM2.5 (-total-pm25-), black carbon (-bc-), ammonium (-nh4-), aerosol nitrate (-no3-), organic carbon (-oc-), and sulfate (-so4-*).

Output also includes model values obtained after taking the difference between a simulation with all sources and multiple simulations with individual source contributors turned off. These sensitivity simulations include UK national emissions of agricultural ammonia (geos-chem-pm25-agr-only.nc), UK national emissions of anthropogenic dust (geos-chem-uk-anthrop-dust-only.nc), continental Europe anthropogenic emissions (geos-chem-uk-europe-only.nc), global natural dust emissions (geos-chem-uk-pm25-global-natural-dust-only.nc), global ship emissions (geos-chem-uk-pm25-global-ships-only.nc), all emission sources in Leicester (geos-chem-uk-pm25-Leicester-only.nc), all emission sources in Leicestershire county (geos-chem-uk-pm25-Leicestershire-only.nc), all emissions in London and Birmingham (geos-chem-London-Bham-only.nc), and UK national traffic tailpipe emissions (geos-chem-uk-pm25-traffic-only.nc).