@PhDThesis{Gavilán:2015:CaReBa,
               author = "Gavil{\'a}n, Hern{\'a}n Rivero",
                title = "Caracteriza{\c{c}}{\~a}o da resposta da baixa ionosfera a 
                         transientes solares",
               school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
                 year = "2015",
              address = "S{\~a}o Jos{\'e} dos Campos",
                month = "2015-05-25",
             keywords = "explos{\~o}es solares, muita baixa frequ{\^e}ncia, SAVNET, 
                         regi{\~a}o-D, solar flares, very low frequency, D-region.",
             abstract = "A partir de observa{\c{c}}{\~o}es obtidas da rede SAVNET entre 
                         abril 2007 e dezembro 2011, per{\'{\i}}odo que corresponde ao 
                         final do m{\'{\i}}nimo do ciclo solar 23 e come{\c{c}}o do 
                         ciclo solar 24, estudamos 366 eventos solares que produziram um 
                         SPA detect{\'a}vel. Durante o per{\'{\i}}odo de estudo obtemos 
                         que o limite de detec{\c{c}}{\~a}o m{\'{\i}}nimo corresponde 
                         {\`a} eventos classe GOES B3.0, com uma probabilidade de 
                         detec{\c{c}}{\~a}o de 39\% e que eventos solares maiores que 
                         classe GOES B.6 possuem uma probabilidade de detec{\c{c}}{\~a}o 
                         de 100\%. A correla{\c{c}}{\~a}o entre os SPAs normalizados 
                         pelo trajeto iluminado versus o logaritmo do excesso de fluxo de 
                         eventos em raios-X e da flu{\^e}ncia solar na banda de 0,5 - 2 A 
                         mostra uma tend{\^e}ncia exponencial, ao serem considerados na 
                         an{\'a}lise eventos fracos com classifica{\c{c}}{\~a}o GOES 
                         inferior a C1. A correla{\c{c}}{\~a}o entre o tempo de 
                         relaxamento, \$\Delta\$t\$_{rel}\$, e o tempo de crescimento 
                         do fluxo solar, \$\Delta\$T\$_{c}\$, sugere que a 
                         tend{\^e}ncia exponencial, quando inclu{\'{\i}}dos os eventos 
                         em raios-X fracos, poderia estar relacionada com a resposta da 
                         ionosfera frente a competi{\c{c}}{\~a}o entre os mecanismos de 
                         fotoioniza{\c{c}}{\~a}o devido ao incremento do fluxo de raios-X 
                         e os processos de recombina{\c{c}}{\~a}o. ABSTRACT: From SAVNET 
                         network database we study 366 solar events that produced SPAs 
                         between April 2007 to December 2011, period that corresponding to 
                         the minimum of the 23\$^{rd}\$ and beginning of the 
                         24\$^{th}\$ solar cycle. During this period we obtained that the 
                         lower limit detection for producing a significant SPA at this VLF 
                         path corresponds to B3.0 GOES class with a probability of 
                         detection of 39\% and that solar flares greater than B6 GOES 
                         class have a probability detection of 100\%. The correlation 
                         between the SPA s normalized intensity by the illuminated path and 
                         by sec (X\$_{mean}\$) versus the logarithm X-ray solar flux peak 
                         excess, the solar fluence in the 0.5 - 2 A band shows an 
                         exponential response when include faint events, with GOES 
                         classification lesser than C1. Correlation between the relaxation 
                         time, \$\Delta\$t\$_{rel}\$, and the crescent time of solar 
                         flux, \$\Delta\$T\$_{c}\$, suggests that such exponential 
                         behavior, observed when including weak events, might be related to 
                         the role of ionospheric response under the competition between 
                         photoionization due the excess of X-rays radiation and 
                         recombination processes.",
            committee = "Nardin, Clezio Marcos de (presidente) and Correia, Em{\'{\i}}lia 
                         (orientadora) and Dal Lago, Alisson (orientador) and Kantor, Ivan 
                         Jelinek and Raulin, Jean-Pierre and Fernandez, Jos{\'e} 
                         Henrique",
           copyholder = "SID/SCD",
         englishtitle = "Characterization of low ionosphere response to solar transients",
             language = "pt",
                pages = "108",
                  ibi = "8JMKD3MGP3W34P/3JU4DU8",
                  url = "http://urlib.net/ibi/8JMKD3MGP3W34P/3JU4DU8",
           targetfile = "publicacao.pdf",
        urlaccessdate = "27 abr. 2024"
}