[摘要] The Global Ozone Monitoring Experiment (GOME) allows the retrieval oftropospheric vertical column densities (VCDs) of NO
2 on a global scale.Regions with enhanced industrial activity can clearly be detected, but thestandard spatial resolution of the GOME ground pixels (320x40km
2) isinsufficient to resolve regional trace gas distributions or individualcities.
Every 10 days within the nominal GOME operation, measurements are executedin the so called narrow swath mode with a much better spatial resolution(80x40km2). We use this data (1997-2001) to construct a detailedpicture of the mean global tropospheric NO2 distribution. Since - dueto the narrow swath - the global coverage of the high resolutionobservations is rather poor, it has proved to be essential to deseasonalizethe single narrow swath mode observations to retrieve adequate mean maps.This is done by using the GOME backscan information.The retrieved high resolution map illustrates the shortcomings of thestandard size GOME pixels and reveals an unprecedented wealth of details inthe global distribution of tropospheric NO2. Localised spots ofenhanced NO2 VCD can be directly associated to cities, heavy industrycenters and even large power plants. Thus our result helps to check emissioninventories.The small spatial extent of NO2 "hot spots" allows us to estimate anupper limit of the mean lifetime of boundary layer NOx of 17h on aglobal scale.The long time series of GOME data allows a quantitative comparison of thenarrow swath mode data to the nominal resolution. Thus we can analyse thedependency of NO2 VCDs on pixel size. This is important for comparingGOME data to results of new satellite instruments like SCIAMACHY (launchedMarch 2002 on ENVISAT), OMI (launched July 2004 on AURA) or GOME II (to belaunched 2005) with an improved spatial resolution.
