Characterizing lightning NOx production in the Ebro Valley with meteosat 12 LI and LMA observations

Kurzfassung

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 TROPOspheric 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.