North American Lightning Detection Network (NALDN) - First Results: 1998-2000

Cloud-to-ground lightning data have been analyzed for the years 1998-2000 for North America (Canada plus the contiguous United States) for all ground flashes, positive flashes, the percentage of positive lightning, peak currents for negative and positive lightning, and for negative and positive multiplicity. The authors examined a total of 88.4 million flashes divided among the three years, 30.6 million (1998), 29.6 million (1999), and 28.3 million (2000). The highest flash densities, uncorrected for flash detection efficiency, occur in the provinces of Alberta and Saskatchewan (1-3 flashes km-2) in Canada, and along the Gulf Coast and in Florida (exceeding 9 flashes km-2) in the United States. Maximum positive flash densities in Canada range from 0.1 to 0.3 flashes km-2 and in the United States, to over 0.7 flashes km-2 (areas in the Midwest, the Gulf Coast, and Florida).