ERA-40: The RETRO reanalysis simulations were constrained with meteorological data from the ERA-40 reanalysis of the European Centre for Medium Range Weather Forecast (ECMWF). For details on how these data were applied, see work package 4.
Emissions: The RETRO emission data sets are described here.
Methane: In order to prevent a possible drift in methane concentrations with consequences on the simulation of OH and consequently tropospheric ozone, methane concentrations in the boundary layer were prescribed as climatological zonal mean values. A long-term climatology including a future scenario was constructed based on data from the NOAA-ESRL sampling network and the IPCC, 2001 report of IPCC working group 1.
Stratospheric ozone: The temporal evolution of stratospheric ozone from 1960-2000 was calculated with the FinROSE model by partner FMI. This proved rather difficult because of excessive meridional overturning in the ERA-40 data set. Nevertheless, the agreement between lower stratospheric ozone concentrations from FinROSE and observations from ozone sondes appears reasonable.
Boundary conditions data sets