@Article{CamposSabaPintBall:2009:WaCoCu,
               author = "Campos, Leandro Zanella de Souza and Saba, Marcelo Magalh{\~a}es 
                         Fares and Pinto J{\'u}nior, Osmar and Ballarotti, 
                         Maur{\'{\i}}cio Grade",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {Instituto Nacional de 
                         Pesquisas Espaciais (INPE)} and {Instituto Nacional de Pesquisas 
                         Espaciais (INPE)}",
                title = "Waveshapes of continuing currents and properties of M-components 
                         in natural positive cloud-to-ground lightning",
              journal = "Atmospheric Research",
                 year = "2009",
               volume = "91",
                pages = "416--424",
             keywords = "Continuing current waveshapes, M-components, Positive lightning, 
                         High-speed video.",
             abstract = "This work analyses the waveshapes of continuing currents and 
                         parameters of M-components in positive cloud-to-ground (CG) 
                         flashes through high-speed GPS synchronized videos. The dataset is 
                         composed of only long continuing currents (with duration longer 
                         than 40 ms) and was selected from more than 800 flashes recorded 
                         in S{\~a}o Jos{\'e} dos Campos (45.864°W, 23.215°S) and 
                         Uruguaiana (29.806°W, 57.005°S) in Southeast and South of Brazil, 
                         respectively, during 2003 to 2007 summers. The videos are compared 
                         with data obtained by the Brazilian Lightning Location System 
                         (BrasilDAT) in order to determine the polarity of each flash and 
                         select only positive cases. There are only two studies of 
                         waveshapes of continuing currents in the literature. One is based 
                         on direct current measurements of triggered lightning, in which 
                         four different types of waveshapes were observed; and the other is 
                         based on measurements of luminosity variations in high-speed 
                         videos of CG negative lightning, in which besides the four types 
                         above mentioned two additional types were observed. The present 
                         work is an extension of the latter, using the same method but now 
                         applied to obtain the waveshapes of positive CG lightning. As far 
                         as the authors know, this is the first report on M-components in 
                         positive continuing currents. We also have used the 
                         luminosity-versus-time graphs to observe their occurrence and 
                         measure some parameters (duration, elapsed time and time between 
                         two successive M-components), whose statistics are presented and 
                         compared in detail to the data for negative flashes. We have 
                         plotted a histogram of the M-components elapsed time over the 
                         total duration of the continuing current for positive flashes, 
                         which presented an exponential decay (correlation coefficient: 
                         0.83), similar to what has been observed for negative flashes.",
                  doi = "10.1016/j.atmosres.2008.02.020",
                  url = "http://dx.doi.org/10.1016/j.atmosres.2008.02.020",
                 issn = "0169-8095",
                label = "self-archiving-INPE-MCTIC-GOV-BR",
             language = "en",
           targetfile = "Atmosph.Research.pdf",
        urlaccessdate = "21 maio 2024"
}