Regional Distribution of Aerosol over Land, Derived from ATSR-2 and GOME

Two aerosol optical depth retrieval algorithms, using different instruments and different methods, are compared. The first method uses both the directional and the spectral information of the Along Track Scanning Radiometer 2 (ATSR-2) to compute the aerosol optical depth in the visible and near-infrared ranges. The second algorithm uses data in the wavelength range between 0.340 μm and 0.400 μm from the Global Ozone Monitoring Experiment (GOME) to determine the aerosol optical depth in the ultraviolet. Both ATSR-2 and GOME are onboard the ERS-2 satellite. The two methods are applied to data from the ERS-2 overpass over northwestern Europe on 25 July 1995. The retrieved aerosol optical depths compare favorably. Also, there is good comparison between satellite retrievals and ground-based measurements. Optical depth images show a large aerosol plume over Belgium and northern France. Back-trajectories indicate that the sources for this aerosol plume are the industrialized regions in Germany and Belgium.