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Nitrogen oxides (NO_xNO+NO₂) play an important role in tropospheric chemistry, in particular in catalytic ozone production. Lightning provides a natural source of nitrogen oxides, dominating the production in the tropical upper troposphere, with strong impact on tropospheric ozone and the atmosphere's oxidizing capacity. Recent estimates of lightning produced NO_x (LNO_x) are of the order of 5 Tg [N] per year with still high uncertainties in the range of one order of magnitude. <P style='line-height: 20px;'> The Global Ozone Monitoring Experiment (GOME) on board the ESA-satellite ERS-2 allows the retrieval of tropospheric column densities of NO₂ on a global scale. Here we present the GOME NO₂ measurement directly over a large convective system over the Gulf of Mexico. Simultaneously, cloud-to-ground (CG) flashes are counted by the U.S.&nbsp;National Lightning Detection Network (NLDN<SUP><SMALL>TM</SMALL></SUP>), and extrapolated to include intra-cloud (IC)+CG flashes based on a climatological IC:CG ratio derived from NASA's space-based lightning sensors. A series of 14&nbsp;GOME pixels shows largely enhanced column densities over thick and high clouds, coinciding with strong lightning activity. The enhancements can not be explained by transport of anthropogenic NO_x and must be due to fresh production of LNO_x. A quantitative analysis, accounting in particular for the visibility of LNO_x from satellite, yields a LNO_x production of 90 (32-240) moles of NO_x, or 1.3 (0.4-3.4) kg [N], per flash. If simply extrapolated, this corresponds to a global LNO_x production of 1.7 (0.6-4.7)Tg [N]/yr.