Lightning is one of the main sources of NO in the Earth's atmosphere. However, there is a large variability in NO production during the lifetime of thunderstorms. In this study, we used the TROPOspheric Monitoring Instrument (TROPOMI) cloud and NO research products along with Lightning Mapping Array (LMA) measurements to investigate the possible relation between the amount of NO produced per lightning flash and flash channel length in the Ebro Valley. We found that there is a positive relationship between both variables. In turn, the vertical structure of the analyzed lightning flashes indicates that longer flashes could release more LNO at lower altitudes than shorter flashes, while higher flash rates produce less LNO per flash. © 2023. The Authors.

The project that gave rise to these results received the support of a fellowship from"la Caixa" Foundation (ID 100010434). The fellowship code is LCF/BQ/PI22/11910026 (F.J.P.I.). Additionally, this work was supported by grants PID2019-109269RB-C43 (F.J.P.I. and F.J.G.V), PID2022-136348NB-C31 (F.J.P.I. and F.J.G.V) and PID2019-109269RB-C42 (O.V.W., J.M. and J.L.) funded by MCIN/AEI/10.13039/501100011033 and "ERDF A way of making Europe." F.J.P.I. and F.J.G.V. acknowledge financial support from the grant CEX2021-001131-S funded by MCIN/AEI/10.13039/501100011033.