Characterizing Lightning NO_x Production in the Ebro Valley with MTG-LI and LMA Observations

Abstract. Lightning is one of the main sources of NOₓ in the Earth’s atmosphere, yet there is considerable variability in NOₓ production during thunderstorms. In this study, we combined optical lightning data from the Meteosat Third Generation (MTG) Lightning Imaging (LI) instrument, which provides information on the occurrence rate and physical characteristics of lightning flashes, measurements from an extended Lightning Mapping Array (LMA) consisting of 24 sensors, lightning measurements from the Lightning Location System (LLS) of the Meteorological Service of Catalonia (MSC), and TROPO-spheric Monitoring Instrument (TROPOMI) cloud and NO₂ research products to investigate lightning NOₓ emissions in the Ebro Valley (Spain). WRF-Chem simulations were used to calculate the necessary air mass factors and to subtract the NOₓ not produced by lightning from the TROPOMI measurements, allowing a more accurate estimation of lightning-induced NOₓ. We found positive relationships between lightning-produced NOₓ per flash and several lightning properties, including flash channel length, radiance, footprint, duration and the length of the optical continuous signal detected from space. These results highlight the importance of combining detailed lightning observations with atmospheric modeling to quantify NOₓ emissions from thunderstorms.