First‐Year Observations From the Meteosat‐12 Lightning Imager: Flash Properties and LI‐FCI Relationships

Abstract The Lightning Imager (LI) is an optical space‐based lightning detector on board the imager platforms of the Meteosat Third Generation program, along with the Flexible Combined Imager (FCI) radiometer. It started delivering data in July 2024, providing unprecedented observations over Europe, Africa, the Atlantic Ocean and a part of South America. This paper presents to the community the statistics of the first year of LI observations, in terms of seasonal lightning density maps, and lightning characteristics like duration, footprint, number of groups and radiance. A comparison with the Météorage ground‐based network is performed, at the flash level, and shows a LI detection efficiency of 76.46% over Western Europe for the summer 2025. Next, case studies combining information from the FCI infrared brightness temperature and LI observations, both flash size and accumulated products, demonstrated that a high density of small flashes can be found in area with cloud top colder than 220K. Conversely, large flashes generally occur in low flash density regions, either in the stratiform part of the cloud or near the edges of the storm. A comparison with the FCI cloud classification suggests that the optical appearance of the cloud‐side flashes is artificially increased by reflection of the optical signal on lower clouds. Overall, the LI instrument presents good quality observations with a strong potential for weather forecasting and research in lightning physics.