The lightning data were obtained from the Global Atmospherics, Incorporated, Tucson, Arizona. The interest and assistance of Ken Cummins in this project are greatly appreciated. We thank Barbara Orville for her editorial assistance. Data handling at Texas A&M University is under the direction of Jerry Guynes and we thank him for his assistance. This research is part of a lightning program supported by the National Science Foundation (ATM-9806189) and the National Oceanic and Atmospheric Administration (Cooperative Agreement NA87WA0063).
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