Figure S3. Timeseries of relative biases of stratospheric ozone (200 - 5 hPa) from the CAMS reanalysis against ozone sondes [(CAMS-obs)/obs in %] (a) for all available stations in the Arctic (60-90⁰N) and (b) at Ny-Ålesund (78⁰55’N, 11⁰55’E) for the period January 2003 to April 2020.
The comparisons against FTIR data, limb sounding satellite data and ozone sondes shown in this section illustrate that the CAMS reanalysis generally has a small negative bias (5-10%) for stratospheric ozone in the Arctic, often within the measurement uncertainties of the instruments.