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Technical description

UBM: A high-resolution air pollution model

The Urban Background Model (UBM, Brandt et al., 2001; 2003) is a high resolution air pollution model for prediction of background concentrations with a 1 km x 1 km resolution. It is capable of calculating hourly values of 17 health related chemical components in the period 1979 to present.

The chemical components include nitrogen-oxides (NOx, NO2), ozone (O3), carbon monoxide (CO), sulphur-dioxide (SO2), particulate matter (PM10, PM2.5), mineral dust, black carbon (BC), organic matter (OM), nitrate (NO3), sulphate (SO4), ammonium (NH4), (and the sum of the latter three; Secondary Inorganic Aerosols (SIA)), ammonia NH3, Secondary Organic Aerosols (SOA) and sea salt.

The model is coupled to the long-range chemical transport model, DEHM, for chemical boundary conditions and to the WRF model for meteorology. UBM is developed for downscaling air pollution at high resolution using a Gaussian plume-in-grid model applying high-resolution emission data and includes chemistry for O3, NO2 and NO. The model is recently validated over a long time period for different countries (see e.g. Hvidtfeldt et al., 2018; Kumar et al., 2019; Khan et al., 2019).

The model has been used for air pollution forecasting at high resolution for cities since 1998 and is a central part of the Danish Air Quality Monitoring Programme for calculating air pollution levels and trends as well as input to the EVA model system for performing assessments of health impacts and related external costs. UBM has been used in many advisory projects for Governmental decision support. The model also forms the basis for a large number of epidemiological and health impact assessment research projects (see e.g., NordicWelfAir.au.dk).