Observations of thunderstorms with a neuromorphic camera: First results of the THOR-DAVIS experiment on the International Space Station.

THOR-DAVIS is an experiment on the International Space Station to observe thunderclouds and their electrical activity with a neuromorphic camera and a co-aligned video camera. A neuromorphic camera, or 'event camera,' only reads pixels when there is a change in pixel illumination, allowing for a temporal resolution that may reach 10 microseconds. Launched by the SpaceX Commercial Resupply Service mission on June 5, 2023, THOR-DAVIS was part of Danish ESA astronaut Andreas Mogensen’s Huginn mission. The scientific focus was to conduct video observations of electrical activity at the cloud tops and the stratosphere above and to extract their altitudes. The technical objective was to test the neuromorphic concept for observations of thunderstorms from space. Andreas Mogensen performed 15 days of observations, passing over 48 thunderstorms, most forecasted by us a day in advance following a procedure inherited from previous ISS experiments (THOR (2015), ILAN-ES (2022)) and some at his own initiative. In all, 36 thunderstorms were recorded in both cameras, totaling ~3 hours of observations. Most notably, Andreas Mogensen secured the first observations of sprites and of an elve with a neuromorphic camera. In addition, numerous lightning flashes, including spider lightning with leader branches extending above the clouds, were observed. The presentation will provide an overview of the THOR-DAVIS payload design, laboratory measurements, and some of the observations from the ISS.