Characteristics of spatiotemporal sizes of specific types of lightning flashes

Abstract:
The duration and horizontal extension distance (HED) of intracloud (IC), negative cloud-to-ground (NCG), positive cloud-to-ground (PCG), and bipolar cloud-to-ground (BCG) lightning are analysed using data from the Oklahoma Lightning Mapping Array and the National Lightning Detection Network. BCG lightning has the greatest average spati-otemporal size, owing to its longest-duration and largest-spatial-extension discharge process after the first return stroke (RS). Compared with NCG lightning, PCG lightning tends to include longer-duration and greater-spatial-extension dis-charge processes before the first RS, making the latter have a larger average spatiotemporal size. IC lightning exhibits the smallest average spatiotemporal size, with a higher concentration of samples in smaller size intervals. The NCG lightning initiated below approximately 6 km tends to exhibit similar HED before the first RS and increased HED after the first RS. However, for NCG lightning initiated above approximately 6 km, the HED before the first RS is notably greater than the increased HED after the first RS.