@InProceedings{PaesBatCanPauJon:2013:IoBeOv,
               author = "Paes, Ricardo da Rosa and Batista, Inez Staciarini and Candido, 
                         Cl{\'a}udia M. N. and Paula, Eurico Rodrigues de and Jonah, 
                         Olusegun Folarin",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {Instituto Nacional de 
                         Pesquisas Espaciais (INPE)}",
                title = "The ionospheric behavior over the Brazilian region during SSW 
                         events",
            booktitle = "Abstracts...",
                 year = "2013",
         organization = "IAGA 2013. - Sientific Assembly, 12.",
             keywords = "ionosphere, SSW events.",
             abstract = "This study refers to the connection between the stratosphere and 
                         ionosphere, investigating, specifically, the behavior of the 
                         equatorial ionization anomaly (EIA) and ionospheric effects over 
                         the Brazilian region during sudden stratospheric warming (SSW) 
                         events that occurred in northern hemisphere winter (2005-2006 and 
                         2008-2009) and a stratospheric warming period that occurred in the 
                         southern hemisphere winter in 2010, when, in both cases, the solar 
                         activity was low. During SSW events, through mechanisms not yet 
                         well known, planetary waves can be amplified and cause 
                         disturbances in the upper atmosphere winds. As it is already 
                         known, the winds are responsible for the dynamo mechanism which 
                         generates the ionospheric electric fields. These fields, in turn, 
                         are fundamental in the formation of the EIA. In this study the 
                         ionospheric behavior was investigated using a parameter ??, which 
                         express the EIA relative intensity for the Brazilian sector. This 
                         parameter is calculated from the ionospheric F2 layer critical 
                         frequency relative variation, which is obtained from Digisondes 
                         installed nearby the geomagnetic equator, S{\~a}o Lu{\'{\i}}s 
                         (2.6° S, 44.2° W) or Fortaleza (3.8° S, 38° W) and near the EIA 
                         southern crest, Cachoeira Paulista (22.5° S, 45° W). The results 
                         for the Brazilian region show, mainly after SSW temperature peak, 
                         an increase in the EIA intensity in the morning, followed by a 
                         decrease in the afternoon. This behavior is preserved for a number 
                         of days equal to the polar region thermal stabilization phase and 
                         it is very similar to the results obtained in pioneering studies 
                         in the Peruvian sector, in which TEC data was used. In the 
                         Brazilian case, the negative variation is stronger than the 
                         positive, being noticeably more intense around the pre-reversal 
                         enhancement time, when the EIA is strongly suppressed.",
  conference-location = "Merida, Mexico",
      conference-year = "aug. 26–31, 2013",
                label = "self-archiving-INPE-MCTI-GOV-BR",
             language = "en",
        urlaccessdate = "15 jun. 2024"
}