%0 Conference Proceedings
%4 dpi.inpe.br/plutao/2011/09.22.17.26.15
%2 dpi.inpe.br/plutao/2011/09.22.17.26.16
%F lattes: 4161737266837399 1 CamposSabaSchuSchu:2011:ChOfM
%T Characterization of M components in positive lightning from high-speed video and electric field data
%D 2011
%A Campos, Leandro Zanella de Souza,
%A Saba, Marcelo Magalhães Fares,
%A Schumann, Carina,
%A Schulz, Wolfgang,
%@affiliation Instituto Nacional de Pesquisas Espaciais (INPE)
%@affiliation Instituto Nacional de Pesquisas Espaciais (INPE)
%@affiliation Instituto Nacional de Pesquisas Espaciais (INPE)
%@affiliation Instituto Nacional de Pesquisas Espaciais (INPE)
%@electronicmailaddress leandro.zanella@gmail.com
%@electronicmailaddress msaba@dge.inpe.br
%B International Symposium on Winter Lightning, 3.
%C Sapporo, Japan
%8 15-16 june
%V 1
%S Proceedings
%K Positive lightning, TLE, Sprites, Lightning Physics, M Components.
%X Recent high-speed video experiments have indicated that positive cloud-to-ground lightning (+CG) might present M components during their continuing current period [1]. As only optical data were available, their results consisted mainly on occurrence- and time-related parameters and their statistical distribution. In the present work we address this issue by extending those investigations through the addition of simultaneous slow and fast electric field data (obtained through the use of capacitive antennas) to the high-speed camera recordings (obtained by two different cameras, Red Lake Motion Scope 8000S and Photron Fastcam 512 PCI, operating at frame rates ranging from 1000 or 8000 frames per second). Through the use of an algorithm previously developed by the authors [1-2] we were able to plot luminosity-versus-time curves of each continuing current recorded by the cameras. Once an individual M component is identified in this luminosity data, it is possible to find the electric field change it has produced and that could be measured by the antennas. By using a simple electrostatic model it is possible to estimate the peak current and total charge transfer to ground of each M component observed from the slow electric field data. These intensity-related parameters can be also be correlated to occurrence- and time-related parameters such as duration, elapsed time since the return stroke and time interval between successive M components, making it possible to see at which periods of a continuing current M components can be more or less intense. This type of data is very relevant for both engineering applications (such as EMC studies [3]) and scientific research (especially sprite initiation [4] and the bidirectional leader model for lightning [5])..
%@language en
%3 3_Campos_ua_ISWL_2011[1].pdf
%O Informações Adicionais: Recent high-speed video experiments have indicated that positive cloud-to-ground lightning (+CG) might present M components during their continuing current period. As only optical data were available, their results consisted mainly on occurrence- and time-related parameters and their statistical distribution. In the present work we address this issue by extending those investigations through the addition of simultaneous slow and fast electric field data (obtained through the use of capacitive antennas) to the high-speed camera recordings (obtained by two different cameras, Red Lake Motion Scope 8000S and Photron Fastcam 512 PCI, operating at frame rates ranging from 1000 or 8000 frames per second). Through the use of an algorithm previously developed by the authors we were able to plot luminosity-versus-time curves of each continuing current recorded by the cameras. Once an individual M component is identified in this luminosity data, it is possible to find the electric field change it has produced and that could be measured by the antennas. By using a simple electrostatic model it is possible to estimate the peak current and total charge transfer to ground of each M component observed from the slow electric field data. These intensity-related parameters can be also be correlated to occurrence- and time-related parameters such as duration, elapsed time since the return stroke and time interval between successive M components, making it possible to see at which periods of a continuing current M components can be more or less intense. This type of data is very relevant for both engineering applications (such as EMC studies) and scientific research (especially sprite initiation and the bidirectional leader model for lightning)..