@MastersThesis{Cruz:2022:LíReRa,
               author = "Cruz, Ivan Toucedo",
                title = "L{\'{\i}}deres de recuo em raios ascendentes",
               school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
                 year = "2022",
              address = "S{\~a}o Jos{\'e} dos Campos",
                month = "2022-03-04",
             keywords = "conex{\~a}o, l{\'{\i}}der de recuo, raio ascendente, 
                         connection, recoil leader, upward lightning.",
             abstract = "O objetivo deste trabalho {\'e} estudar os processos de 
                         propaga{\c{c}}{\~a}o dos l{\'{\i}}deres de recuo em raios 
                         ascendentes negativos. Os l{\'{\i}}deres de recuo s{\~a}o 
                         originados em todos os raios (ascendentes, descendentes e 
                         intranuvem), ocorrendo em canais deca{\'{\i}}dos de 
                         l{\'{\i}}deres positivos. Eles s{\~a}o respons{\'a}veis por 
                         alguns processos f{\'{\i}}sicos, tais como: tentativa de 
                         l{\'{\i}}der; l{\'{\i}}der cont{\'{\i}}nuo; l{\'{\i}}der 
                         cont{\'{\i}}nuo escalonado; componente M; entre outros. Para 
                         estudar os l{\'{\i}}deres de recuo foram escolhidos os raios 
                         ascendentes negativos, pois possuem l{\'{\i}}deres positivos se 
                         propagando do solo em dire{\c{c}}{\~a}o {\`a} nuvem. 
                         Diferentemente dos raios intranuvem e descendentes que possuem as 
                         ramifica{\c{c}}{\~o}es dos l{\'{\i}}deres positivos dentro da 
                         nuvem; estes raios n{\~a}o apresentam obstru{\c{c}}{\~a}o na 
                         visualiza{\c{c}}{\~a}o dos l{\'{\i}}deres de recuo, 
                         facilitando as an{\'a}lises. Durante o desenvolvimento desta 
                         disserta{\c{c}}{\~a}o foram analisados oito casos de raios 
                         ascendentes negativos. Um dos resultados foi a 
                         visualiza{\c{c}}{\~a}o de l{\'{\i}}deres de recuo 
                         secund{\'a}rios se conectando a l{\'{\i}}deres de recuo 
                         precedentes. Por meio dessa caracter{\'{\i}}stica foi 
                         poss{\'{\i}}vel compreender melhor alguns processos 
                         f{\'{\i}}sicos produzidos nesses raios. Tamb{\'e}m foi 
                         observado que as propaga{\c{c}}{\~o}es de l{\'{\i}}deres na 
                         nuvem impulsionam o desenvolvimento de l{\'{\i}}deres de recuo 
                         nos raios ascendentes negativos, podendo gerar conex{\~o}es entre 
                         eles. Foram mostrados dois eventos in{\'e}ditos de conex{\~o}es 
                         de l{\'{\i}}deres de recuo com l{\'{\i}}deres positivos na 
                         nuvem, que posteriormente produziram descargas de retorno 
                         subsequentes positivas. Por fim, foi poss{\'{\i}}vel visualizar 
                         em todos os casos analisados l{\'{\i}}deres de recuo 
                         apresentando um padr{\~a}o caracter{\'{\i}}stico. Eles se 
                         desenvolviam pelas bifurca{\c{c}}{\~o}es dos raios ascendentes, 
                         assumindo a forma da letra V do alfabeto romano. Esse padr{\~a}o 
                         caracter{\'{\i}}stico foi explicado durante o desenvolvimento 
                         deste trabalho. ABSTRACT: The aim of this work is to study the 
                         process of propagation of the recoil leaders in negative upward 
                         lightning. The recoil leaders are originated in all lightning 
                         (upward, downward and intracloud), occurring in fallen channels of 
                         positive leaders. They are responsible for some physical 
                         processes, such as: attempt leader; dart leader; dart step leader; 
                         component M; among others. To study the recoil leaders, negative 
                         upward lightning were chosen, because they have positive leaders 
                         propagating from the ground towards the cloud. Differently from 
                         intracloud and downward lightning that have the ramifications of 
                         positive leaders within the cloud; these lightning do not present 
                         any obstruction in the visualization of the recoil leaders, 
                         facilitating the analysis. During the development of this 
                         dissertation, eight cases of negative upward lightning were 
                         analyzed. One result was the visualization of secondary recoil 
                         leaders connecting to preceding recoil leaders. Through this 
                         feature, it was possible to better understand some physical 
                         processes that occur in these lightning. It was also observed that 
                         the propagation of leaders in the cloud boost the development of 
                         recoil leaders in negative upward lightning, being able generate 
                         connections between them. Two unprecedented events of recoil 
                         leader connections with positive leader in the cloud were shown, 
                         which subsequently produced positive subsequent return stroke. 
                         Finally, it was possible to visualize, in all analyzed cases, 
                         recoil leaders preseting a characteristic pattern. They developed 
                         through the bifurcations of the upward lightning, assuming the 
                         form of the letter V of the roman alphabet. This characteristic 
                         pattern was explained during the development of this work.",
            committee = "Silva, Marlos Rockenbach da (presidente) and Saba, Marcelo 
                         Magalh{\~a}es Fares (orientador) and Naccarato, Kleber Pinheiro 
                         and Ferro, Marco Antonio da Silva",
         englishtitle = "Recoil leaders in upward lightning",
             language = "pt",
                pages = "92",
                  ibi = "8JMKD3MGP3W34T/46GLSC2",
                  url = "http://urlib.net/ibi/8JMKD3MGP3W34T/46GLSC2",
           targetfile = "publicacao.pdf",
        urlaccessdate = "20 abr. 2024"
}