EPISODE is a city-scale 3D-grid Eulerian numerical model with embedded sub-grid gaussian plume and parameterized models for the estimation of refined point ambient concentrations. It has been developed at NILU with a special focus on the Nordic meteorological and chemical conditions. It can consider coarse emissions in the grid, but also consider emissions at high resolution as lines (e.g., roads) and points (e.g., stack chimneys). In its most simplified setup, it considers the atmospheric processes advection, diffusion, and a photostationary steady-state approximation for NO2. As necessary, the complexity can be expanded to consider further chemistry and other processes, including the use of the NORTRIP dust emission model when analysing PM10 ambient concentrations  and the METVED residential heating emission model for PM2.5 concentrations, which are both very relevant in the Nordic countries.

This model can calculate ambient concentrations representative of what is being inhaled by urban inhabitants and in this way it is fit-for-purpose for Air Quality assessments and for Air Quality Planning with the view on bettering the Air Quality in cities.

Annually averaged NO2 concentrations (µg m−3) from the EPISODE model over Oslo (100 m×100 m horizontal resolution) for 2015. The black triangles indicate the locations of air quality observation stations. The dark shaded areas represent the sea, lakes, and rivers. The black lines are roads.
© OpenStreetMap contributors 2019. Distributed under a Creative Commons BY-SA License.

Contact person(s):

Gabriela Sousa Santos (gss@nilu.no) and Paul Hamer (pdh@nilu.no)

References:

PART 1: https://gmd.copernicus.org/articles/13/4323/2020/
PART 2: https://gmd.copernicus.org/articles/12/3357/2019/

Examples of Air Quality Assessment and Measures:

OSLO:

Traffic and air quality calculations. In connection with revised assessment of measures for improved air quality in Oslo and Bærum for 2025-2030. Results for Oslo

Costs and benefits of implementing an Environmental Speed Limit in a Nordic city

Evaluation of traffic control measures in Oslo region and its effect on current air quality policies in Norway

BERGEN: Revised local air quality assessment in Bergen

DRAMMEN: Revised air quality assessment for Drammen municipality

STAVANGER: Revised assessment of local air quality in Stavanger

TROMSØ: Revised air quality assessment for Tromsø

Air Quality and Climate objectives harmonization:

DUBLIN: https://www.epa.ie/publications/research/climate-change/research-286-conair-addressing-conflicts-of-climate-and-air-pollution.php
NORTRIP: https://www.nilu.no/apub/26896/
METVED: https://acp.copernicus.org/articles/19/10217/2019/