5. Summary and conclusions
ISS LIS has completed more than three years on orbit. During that time, it has met all of its major science objectives, including detection of lightning during day and night, at storm-scale (~4-km) spatial resolution, with millisecond timing and reasonably high flash detection efficiency (64% relative to a comparable optical sensor) without a land/ocean bias. ISS LIS also measures radiant energy, which though not discussed in depth in this paper is relevant to many studies such as NOx generation by lightning [e.g.,Pickering et al. , 2016] and differences in land/ocean flash characteristics [e.g., Nag and Cummins , 2017]. ISS LIS also provides background images/intensity, and delivers near-realtime lightning data. In addition, it has produced a lightning climatology that is fundamentally consistent with previous lightning climatologies, while also enabling the extension of the climatologies into the current era as well as to higher latitudes (± 55°). Global-scale flash rates (3-year average: ~44 s-1) are within 5-10% of previous datasets [e.g., Cecil et al. , 2014], and the spatial and diurnal distributions of global lightning are consistent with expectations [e.g., Blakeslee et al. , 2014]. ISS LIS has demonstrated its value as a calibration/validation tool for current and future spaceborne lightning datasets. The near-realtime ISS LIS data have opened up applications within operational weather forecasting and related applications, including public safety. Finally, ISS LIS is demonstrating utility as part (or potential part) of cross-platform studies examining a diverse array of topics, including lightning physics, thunderstorm processes, convective precipitation, and atmospheric composition.