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Meteorological Aspects Related To Cloud-To-Ground Lightning Ocurrence In Minas Gerais During The Summer Of 1995/96
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 6th International Congress of the Brazilian Geophysical Society, Aug 1999, cp-215-00140
Abstract
Lightning strokes recorded in Southeast Brazil during the summer of 1995/96 in a period of aproximately one<br>month were studied. The main parameters of the discharges (position, date, time, polarity, peak current) were<br>determined and analyzed. Using these data, the mean number of strokes per hour and per day, as well as the<br>mean values of the peak current were calculated. Within the period considered it was possible to distinguish<br>days of high electrical activities from periods of low activities. Those bursts and breaks were characterized<br>meteorologicaly by means of infrared immagery from the GOES satellite and reanalisys data from NCEP. The<br>later were used to calculate the wind fields, the moisture flux convergence, the specific humidity and the<br>equivalent potential temperature. The meteorological systems were identified, and a relashionship was<br>observed between the diurnal cycle of the negative strokes and the meteorological conditions. The correlations<br>between positive and negative discharges and the equivalent potential temperature were determined. It was<br>concluded that the negative strokes, as well as positive strokes with peak currents above 15 kA show good<br>correlations with the equivalent potential temperature. Such a variable seems to be a good parameter for<br>evaluating the electrical activity, as it is for evaluating the depth and vigor of convection.