Sprites Observed by ASIM: First Imaging Data Set and Temporal UV Emission Patterns

We present the first data set analysis of 41 imaging‐confirmed sprite events detected by the ASIM‐MMIA instrument. They were visible in the 337 nm camera images from an initial list of 102 candidates identified by the ultraviolet (UV 180–230 nm) photometer. The spatial distribution of confirmed sprites (mapped with the ASIM‐MMIA imaging locations) reveals a distribution largely constrained to land areas and pronounced tropical clustering, with 61% of events over Africa, 24% in the Americas, 12% in Asia, and 2% in Europe. Cloud‐to‐ground (CG) lightning parent strokes were positive in 89% of the cases and negative in 11% according to the GLD360 network. High‐resolution UV photometer temporal profiles enabled classification into three groups: (a) Elve‐preceded sprites (20% of events), featuring a short rise‐time UV peak (∼150 µs) during the elve and a short sprite onset delay (<4 ms in 75% of cases) associated with >100 kA positive strokes; (b) Single‐peak UV sprites (56%), exhibiting one major UV pulse delayed by 100–1,000 ms; and (c) Multiple‐peak UV sprites (24%), characterized by several UV peaks and pronounced long‐continuing currents. Both groups 2 and 3 exhibited UV rise‐times between 1 and 2 ms. Comparative high‐speed ground‐based video confirms that the MMIA‐UV photometer reliably captures maximum sprite irradiance, though low‐intensity substructures might fall below detection thresholds. Space‐based sprite imaging at 337 nm confirmed column, carrot and branching structures consistent with ground observations, demonstrating Atmosphere‐Space Interactions Monitor capability to resolve sprite morphology from orbit.