in this paper size and duration of lightning flashes are examined. Data from the Ebro Valley Laboratory Lightning Mapping Array is used as reference. Additional data from the VLF/LF LINET network and meteorological radar is included. In order to simplify the complex geometry of a lightning flash, each flash is described by a confidence ellipse fitting most of the detected sources. The flash length is represented by the major axis of the ellipse. The analysis of 778 flashes results in a median flash length of 14 km with a median duration of 0.3 s. The results presented here, besides characterizing the storm activity, provide valuable information in order to improve the stroke grouping criteria in the flash algorithm, lightning flash density calculations and lightning warning procedures.

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