Tropospheric NO2 from GOME measurements Original Research Article

Measurements from the Global Ozone Monitoring Experiment (GOME) have been analysed for tropospheric NO2 using the Differential Optical Absorption method. The retrieval technique is described and a detailed error analysis is given. A case study of tropospheric NO2 above Africa in fall 1997 is presented, showing the influence of both biomass burning and lightning. Comparison of clear and cloudy pixels reveals, that substantial amounts of NO2 are present in the free troposphere over the African continent and in the outflow regions over the Southern Atlantic and the Indian Ocean. This has important implications for the formation of the tropospheric ozone maxima observed in these areas.