Lightning study in association of mesoscale convective systems in the Southest region of Brazil / Estudo das Descargas Elétricas Atmosféricas associadas a sistemas convectivos de mesoescala para a Região Sudeste do Brasil

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

In this work it is presented the study of 6 years of detected lightning data in association to the occurrence of mesoscale convective systems in the region located between 15S - 27S and 35W - 55W. The Lightning data were provided by FURNAS Centrais Elétricas S.A. for the period 2002-2007. Geostationary satellite images, enhanced in the infrared channel, were used to identify the cases of interest utilizing -50C as cloud top level temperature threshold for convective clusters. For these days, lightning detected in the study region should attain a minimum value of 1000 during 1 hour in some moment of occurrence during the identified cases. From the 565 days that satisfied this criterion, it was selected 25 cases occurred in 33 days during the years of 2003, 2005 (from October to December due to satellite images limitations), 2006 and 2007. For the period of occurrence of each one of these 25 cases, the detected lightning were counted during an interval of 15 minutes before and after the time of the satellite images used in each case to put in evidence the lightning associated to the observed convective clusters. The quantity of detected lightning in a convective cluster were related to its evolutive cycle.

ASSUNTO(S)

meteorologia lightning mesoscale convective systems região sudeste sistemas convectivos de mesoescala southeast region descargas elétricas atmosféricas

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