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Lightning Characteristics In The Southeastern Region Of Brazil: 1999-2000
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 7th International Congress of the Brazilian Geophysical Society, Oct 2001, cp-217-00353
Abstract
Studies on lightning characteristics have been performed<br>in Brazil since 1988 using lightning location<br>systems (called here SLT). In this work the lightning<br>characteristics in the southeastern region of Brazil<br>during summer and winter of 1999 and 2000 were<br>analyzed. Over a million atmospheric discharges were<br>registered by the SLT system owned by CEMIG<br>(Companhia Energética de Minas Gerais). The main<br>objective was to determine the mean values for summer<br>and winter of four basic parameters: the percentage<br>of positive lightning, the peak current, the multiplicity,<br>and the peak current of single and multiple<br>lightning discharges. It was concluded that the peak<br>currents of negative lightning are less intense than the<br>peak currents of positive discharges. However, the<br>negative lightning have a greater number of return<br>strokes with a mean value of 1.74 while in positive<br>lightning the mean value of strokes is 1.05. Negative<br>discharges tend to be more intense in summer with a<br>mean peak current of 36.9kA. The correspondent<br>winter value is 29.9kA. Positive lightning present an<br>inverse behavior with a mean value of 46.9kA in<br>summer and 50.5kA in winter. It was observed that<br>single lightning (both positive and negative) were less<br>intense than the first return stroke of multiple lightning.