Abstract:
A network of ground-based UV/visible DOAS instruments operated by the University of Bremen is used to validate total column measurements from the SCIAMACHY instrument on ENVISAT from the tropics to the Arctic. Measurement quantities include vertical columns of O3, NO2, and BrO. Depending on atmospheric conditions, also slant columns of OClO (during chlorine activation) and SO2, HCHO or IO can be measured. In addition to the standard zenith-sky measurement, all instruments perform off-axis horizon measurements that provide information on the tropospheric burden of the observed species. This quantity will also be used for validation once tropospheric products become available from SCIAMACHY