Underlying data for CopernicusAtmosphere/air-quality-covid19-response

Hello, for https://github.com/CopernicusAtmosphere/air-quality-covid19-response I would like to know, which are the model runs that are used and how the data is produced. Is there a documentation? For us it is particularly relevant if there is a urban scheme involved and which are the emission-, the in-situ- and the satellite data assimilated, so which products go into there? How are urban cities treated in the model? Thanks a lot