@Article{NogueiraAbSoDeBaCoSi:2018:LaDeRe,
               author = "Nogueira, Paulo A. B. and Abdu, Mangalathayil Ali and Souza, Jonas 
                         Rodrigues de and Denardin, Clezio Marcos and Barbosa Neto, Paulo 
                         Fran{\c{c}}a and Costa, Jo{\~a}o P. Serra de Souza da and Silva, 
                         Ana P. M.",
          affiliation = "Instituto Federal de Educa{\c{c}}{\~a}o, Ci{\^e}ncia e 
                         Tecnologia de S{\~a}o Paulo (IFTSP) and {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)} and 
                         Instituto Federal de Educa{\c{c}}{\~a}o, Ci{\^e}ncia e 
                         Tecnologia de S{\~a}o Paulo (IFTSP) and Instituto Federal de 
                         Educa{\c{c}}{\~a}o, Ci{\^e}ncia e Tecnologia de S{\~a}o Paulo 
                         (IFTSP)",
                title = "Latitude-dependent delay in the responses of the equatorial 
                         electrojet and Sq currents to X-class solar flares",
              journal = "Annales Geophysicae",
                 year = "2018",
               volume = "36",
               number = "1",
                pages = "139--147",
             keywords = "Ionosphere (equatorial ionosphere).",
             abstract = "We have analyzed low-latitude ionospheric current responses to two 
                         intense (X-class) solar flares that occurred on 13 May 2013 and 11 
                         March 2015. Sudden intensifications, in response to solar flare 
                         radiation impulses, in the Sq and equatorial electrojet (EEJ) 
                         currents, as detected by magnetometers over equatorial and 
                         low-latitude sites in South America, are studied. In particular we 
                         show for the first time that a 5 to 8 min time delay is present in 
                         the peak effect in the EEJ, with respect that of Sq current 
                         outside the magnetic equator, in response to the flare radiation 
                         enhancement. The Sq current intensification peaks close to the 
                         flare X-ray peak, while the EEJ peak occurs 5 to 8 min later. We 
                         have used the Sheffield University Plasmasphere-Ionosphere Model 
                         at National Institute for Space Research (SUPIM-INPE) to simulate 
                         the E-region conductivity enhancement as caused by the flare 
                         enhanced solar extreme ultraviolet (EUV) and soft Xrays flux. We 
                         propose that the flare-induced enhancement in neutral wind 
                         occurring with a time delay (with respect to the flare radiation) 
                         could be responsible for a delayed zonal electric field 
                         disturbance driving the EEJ, in which the Cowling conductivity 
                         offers enhanced sensitivity to the driving zonal electric field.",
                  doi = "10.5194/angeo-36-139-2018",
                  url = "http://dx.doi.org/10.5194/angeo-36-139-2018",
                 issn = "0992-7689",
                label = "self-archiving-INPE-MCTIC-GOV-BR",
             language = "en",
           targetfile = "nogueira_latitude.pdf",
        urlaccessdate = "27 abr. 2024"
}