Análise das características das nuvens convectivas geradoras e não geradoras de descargas elétricas atmosféricas no estado de Alagoas

Abstract

This study aimed to analyze the differences between generating and nonlightning clouds in the state of Alagoas, using data from Meteosat and lightning location data from WWLLN (Word Wide Lightning Location Network). For this, the difference in brightness temperature between channels 6.2 and 10.8 of Meteosat was used to analyze the depth of convection of the clouds on the days studied, and the difference in brightness temperature between channels 8.7 and 10.8 to analyze ice formation. , as well as the 10.8 channel brightness temperature. From this, thresholds of values above -5 K were found as characteristics of the generating clouds for the difference between channels 6.2 and 10.8, values below 240K for brightness temperature of channel 10.8 and differences close to 0 K between the channels 8.7 and 10.8, the difference between the water vapor channel and the infrared channel being more characteristic in the distinction between the lightning and nonlightning clouds. For the presence or formation of ice at the top of the clouds, it was observed that both the lightning and nonlightning clouds had not only ice but also super-cooled water, which is not so different for these two situations. It was also observed that the greater the amount of ice in relation to super-cooled water was observed, the less frequency of lightning clouds discharged.