author = "Silva, Regia Pereira and Sobral, Jose Humberto Andrade and Koga, 
                         Daiki and Souza, Jonas Rodrigues",
          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 = "Evidence of prompt penetration electric fields during HILDCAA 
              journal = "Annales Geophysicae",
                 year = "2017",
               volume = "35",
                pages = "1165--1176",
             keywords = "Ionosphere (equatorial ionosphere, ionosphere– magnetosphere 
                         interactions, ionospheric disturbances).",
             abstract = "High-intensity, long-duration continuous auroral electrojet (AE) 
                         activity (HILDCAA) events may occur during a long-lasting recovery 
                         phase of a geomagnetic storm. They are a special kind of 
                         geomagnetic activity, different from magnetic storms or substorms. 
                         Ionized particles are pumped into the auroral region by the action 
                         of Alfv{\'e}n waves, increasing the auroral current system. The 
                         Dst index, however, does not present a significant downward swing 
                         as it occurs during geomagnetic storms. During the HILDCAA 
                         occurrence, the AE index presents an intense and continuous 
                         activity. In this paper, the response of Brazilian equatorial 
                         ionosphere is studied during three HILDCAA events that occurred in 
                         the year of 2006 (the descending phase of solar cycle 23) using 
                         the digisonde data located at S{\~a}o Lu{\'{\i}}s, Brazil 
                         (2.33\◦ S, 44.2\◦ W; dip latitude 1.75\◦ S). 
                         Geomagnetic indices and interplanetary parameters were used to 
                         calculate a cross-correlation coefficient between the Ey component 
                         of the interplanetary electric field and the F2 electron density 
                         peak height variations during two situations: the first of them 
                         for two sets daytime and nighttime ranges, and the second one for 
                         the time around the pre-reversal enhancement (PRE) peak. The 
                         results showed that the pumping action of particle precipitation 
                         into the auroral zone has moderately modi- fied the equatorial F2 
                         peak height. However, F2 peak height seems to be more sensitive to 
                         HILDCAA effects during PRE time, showing the highest variations 
                         and sinusoidal oscillations in the cross-correlation indices.",
                  doi = "10.5194/angeo-35-1165-2017",
                  url = "http://dx.doi.org/10.5194/angeo-35-1165-2017",
                 issn = "0992-7689",
             language = "en",
           targetfile = "silva_evidence.pdf",
        urlaccessdate = "01 dez. 2020"