High resolution multi-scale air quality modelling for all streets in Denmark

- Annual concentrations of NO2, PM2.5 and PM10 have been modelled for all addresses in Denmark.
- A multi-scale modelling approach is applied and validated again measurements.
- Traffic data from a newly developed national Danish Transport Model is used.
- A national travel speed dataset based on GPS readings of vehicles is used.
- An air quality map was made publicly available on a website in September 2016 (http://luftenpaadinvej.au.dk).

The annual concentrations of NO2, PM2.5 and PM10 in 2012 have for the first time been modelled for all 2.4 million addresses in Denmark based on a multi-scale air quality modelling approach. All addresses include residential, industrial, institutional, shop, school, restaurant addresses etc. The approach is based on a suite of chemistry-transport models all developed at Aarhus University and includes regional modelling, urban background modelling and street modelling. Information about traffic volumes is based on a newly developed national Danish Transport Model, and national travel speed data have been obtained from a recent dataset based on GPS readings of vehicles. Air quality model results are validated by comparisons with measurements obtained from the fixed site monitoring stations under the Danish Air Quality Monitoring Programme. The validation showed that calculated street concentrations of NO2 for the five available street monitoring stations are within −27% to +12%. The model results were also verified with comparisons with previous model results for NO2 at 98 selected streets in Copenhagen and 31 streets in Aalborg. The verification showed good correlation in Copenhagen (r2 = 0.70) and fairly good agreement in Aalborg (r2 = 0.60). The target groups for the air quality mapping of all Danish addresses are the general public for information and awareness about air quality, and local and national authorities whom may use the information as a screening tool for air quality assessment. The air quality map has been provided on a WebGIS platform on the internet in September 2016 (http://luftenpaadinvej.au.dk). The air quality map is named AirStreet for Air Quality at Your Street.