Monitoring of trace gas emissions from space: tropospheric abundances of BrO, NO_2, H_2CO, SO_2, H_2O, O_2 and O_4 as measured by GOME

摘要

The Global Ozone Monitoring Experiment (GOME) was launched in April 1995 and is since then continuously operating. GOME consists of four separate channels covering the spectral range from 240 to 790 nm with a moderate spectral resolution of 0.2 to 0.4 nm (FWHM). Originally designed for the measurement of ozone it was also possible to identify a large variety of trace gas absorptions of additional atmospheric species in the spectra recorded by GOME. These include several species which are located mostly or at least partly in the troposphere like BrO, NO_2, HCHO, SO_2, and H_2O, O_2, and O_4. Here we present an overview on the analysis and the interpretation of these measurements. While some products (like BrO and NO_2) are already analysed on a routine basis, some others like SO_2 and HCHO are investigated in case studies. Because of the large size of the ground pixels observed by GOME (40 x 320 km~2) nearly all GOME measurements are at least partly covered by clouds which strongly affect the analysis of the tropospheric absorbers. Examples of a cloud correction based on several parameters measured by GOME including e.g. the absorptions of atmospheric oxygen (O_2) and the oxygen dimer (O_4) are presented.