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@PhDThesis{Ballarotti:2015:ReLíPo,
               author = "Ballarotti, Maur{\'{\i}}cio Grade",
                title = "Redesenvolvimento do l{\'{\i}}der positivo no rel{\^a}mpago",
               school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
                 year = "2015",
              address = "S{\~a}o Jos{\'e} dos Campos",
                month = "2015-04-23",
             keywords = "rel{\^a}mpago, l{\'{\i}}der, descarga el{\'e}trica, descarga 
                         atmosf{\'e}rica, quebra de rigidez, lightning, leader, electrical 
                         discharge, atmospheric discharge, electrical breakdown.",
             abstract = "Neste trabalho {\'e} caracterizado o processo interno do 
                         rel{\^a}mpago chamado ent{\~a}o de \${{"}}\$l{\'{\i}}der de 
                         recuo\${{"}}\$(LR), respons{\'a}vel pelo redesenvolvimento do 
                         l{\'{\i}}der positivo atrav{\'e}s da quebra de rigidez nos 
                         diversos tipos de rel{\^a}mpagos. {\'E} o processo que, de certo 
                         modo, foi menos estudado e compreendido, ao mesmo tempo em que tem 
                         sido observado indiretamente h{\'a} quase um s{\'e}culo. A 
                         revis{\~a}o da literatura contemplou os seguintes t{\'o}picos: o 
                         ambiente el{\'e}trico do rel{\^a}mpago na nuvem de tempestade; 
                         os processos internos do rel{\^a}mpago nuvem-solo negativo 
                         (quebra de rigidez preliminar, l{\'{\i}}der escalonado, 
                         l{\'{\i}}der ascendente conectivo, descarga de retorno, 
                         l{\'{\i}}deres subsequentes, corrente cont{\'{\i}}nua e 
                         componente M, e processos K e J), do nuvem-solo positivo e dos 
                         ascendentes; o l{\'{\i}}der de recuo; e o rel{\^a}mpago como um 
                         l{\'{\i}}der bidirecional. Foram realizadas duas an{\'a}lises 
                         paralelas de registros do l{\'{\i}}der positivo, com foco no seu 
                         redesenvolvimento: uma baseada em c{\^a}mera r{\'a}pida com o 
                         l{\'{\i}}der exposto fora da nuvem para 18 rel{\^a}mpagos 
                         nuvem-solo positivos e ascendentes negativos, e outra baseada em 
                         c{\^a}mera r{\'a}pida e antenas de campo el{\'e}trico com o 
                         l{\'{\i}}der dentro da nuvem para 16 rel{\^a}mpagos nuvem-solo 
                         negativos. As duas an{\'a}lises foram discutidas em comum nos 
                         seguintes aspectos: caracter{\'{\i}}sticas do l{\'{\i}}der de 
                         recuo (regime, sentido de propaga{\c{c}}{\~a}o, local de 
                         inicia{\c{c}}{\~a}o e assinatura de campo el{\'e}trico); o 
                         l{\'{\i}}der de recuo na estrutura do l{\'{\i}}der positivo 
                         (propaga{\c{c}}{\~a}o do ramo que sofre a ocorr{\^e}ncia dos 
                         l{\'{\i}}deres de recuo, localiza{\c{c}}{\~a}o de uma 
                         s{\'e}rie de l{\'{\i}}deres de recuo, dire{\c{c}}{\~a}o de 
                         propaga{\c{c}}{\~a}o do l{\'{\i}}der de recuo, 
                         fun{\c{c}}{\~o}es do l{\'{\i}}der de recuo e extens{\~a}o de 
                         sua propaga{\c{c}}{\~a}o, taxas de gera{\c{c}}{\~a}o e 
                         particularidades nos diferentes tipos de rel{\^a}mpagos); 
                         intera{\c{c}}{\~a}o do l{\'{\i}}der de recuo com outros 
                         processos (agrupamento, interatividade, interatividade 
                         c{\'{\i}}clica e taxas m{\'e}dias de gera{\c{c}}{\~a}o de 
                         l{\'{\i}}deres de recuo durante diferentes processos no 
                         nuvem-solo negativo); e sobre o mecanismo de disparo do LR. Um 
                         resultado particularmente importante desta tese trata sobre o 
                         papel de uma m{\'{\i}}nima diferen{\c{c}}a de potencial sobre o 
                         ramo deca{\'{\i}}do para o disparo do l{\'{\i}}der de recuo. 
                         Baseado em diversas evid{\^e}ncias sintetizadas ao longo das duas 
                         an{\'a}lises, foi elaborado um modelo el{\'e}trico simplificado 
                         do disparo do l{\'{\i}}der de recuo, aplic{\'a}vel a diferentes 
                         tipos e situa{\c{c}}{\~o}es observadas de rel{\^a}mpagos. Tal 
                         diferen{\c{c}}a de potencial {\'e} apresentada em 
                         fun{\c{c}}{\~a}o da temperatura e do comprimento do ramo 
                         deca{\'{\i}}do. Sugere-se a mudan{\c{c}}a na nomenclatura de 
                         l{\'{\i}}der de recuo para l{\'{\i}}der de redesenvolvimento. 
                         ABSTRACT: This thesis characterizes the internal lightning process 
                         called recoil leader, which is responsible for the positive leader 
                         redevelopment based on breakdown in many types of lightning 
                         discharges. This process is somehow the least analyzed and 
                         understood, at the same time that it has been indirectly observed 
                         for almost a century. The literature review treated the following 
                         subjects: thunderstorm electrical environment for lightning; 
                         internal processes of the negative cloud-to-ground lightning 
                         (preliminary breakdown, stepped-leader, upward connecting leader, 
                         return stroke, subsequent leaders, continuing current and M 
                         component, K and J processes), of the positive cloud-to-ground and 
                         the upward lightning; recoil leader; and lightning as a 
                         bidirectional leader. Two analyses of the positive leader were 
                         performed in parallel, focusing on its redevelopment: one based on 
                         high-speed camera records of exposed leader (outside the cloud) on 
                         18 events of positive cloud-to-ground and negative upwards, and 
                         the other based on high-speed camera and electric field antennas 
                         records of hidden leader (inside the cloud) on 16 events of 
                         negative cloud-to-ground lightning. Both analyses were discussed 
                         together in the following topics: recoil leader characteristics 
                         (regime, propagation direction, initiation location and electric 
                         field signature); recoil leader in the positive leader structure 
                         (branch propagation during recoil leader, location of a recoil 
                         leader series, propagation direction and extent of the recoil 
                         leader, recoil leader roles, generation rates, particular 
                         behaviors in different lightning types); recoil leader interaction 
                         with other process (grouping, interactivity, cyclic interactivity, 
                         recoil leader generating rates during different processes of the 
                         negative cloud-to-ground lightning); and about the recoil leader 
                         triggering mechanism. A particularly important result of the 
                         present thesis shows the key role of a minimum potential 
                         difference over the decayed branch as an important condition for 
                         recoil leader triggering. Based on several evidences synthesized 
                         from both analyses, a simplified electrical model of the recoil 
                         leader triggering was developed, and applied to different 
                         lightning types and conditions. Such potential difference is 
                         presented as a function of decayed branch temperature and length. 
                         In terms of nomenclature, it is also suggested redevelopment 
                         leader instead of recoil leader.",
            committee = "Lago, Alisson Dal (presidente) and Pinto Junior, Osmar 
                         (orientador) and Saba, Marcelo Magalh{\~a}es Fares (orientador) 
                         and Souza, Jonas Rodrigues de and Piantini, Alexandre and 
                         Martinez, Manuel Luiz Barreira and Ferro, Marco Antonio da Silva",
           copyholder = "SID/SCD",
         englishtitle = "Positive leader redevelopment in lightning",
             language = "pt",
                pages = "226",
                  ibi = "8JMKD3MGP3W34P/3J7Q4E8",
                  url = "http://urlib.net/rep/8JMKD3MGP3W34P/3J7Q4E8",
           targetfile = "publicacao.pdf",
        urlaccessdate = "01 dez. 2020"
}


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