To gain more quantitative insights into the location, brightness, mobility, and shape of the discharges, we created a Python-based toolbox that extracts these parameters for each discharge for each frame. For the following results, we use a dataset consisting of 6000 frames and ca. 55 000 discharge spots. Note that the number of distinct discharges is lower since they appear as individual spots in consecutive images (see discharges followed by arrows in Fig. ). The code for extracting the individual discharge spots from its local brightness in the image can be found in the Data Availability Statement. In the following, we only focus on the conceptual ideas and the results.