@Article{FontesMRJFBPTA:2024:EfNoHe,
               author = "Fontes, Pedro A. and Muella, M{\'a}rcio Tadeu A. H. and Resende, 
                         Laysa Cristina Ara{\'u}jo and Jesus, Rodolfo de and Fagundes, 
                         Paulo R. and Batista, Paulo Prado and Pillat, Valdir G. and 
                         Tardelli, Alexandre and Andrioli, V{\^a}nia F{\'a}tima",
          affiliation = "{Universidade do Vale do Para{\'{\i}}ba (UNIVAP)} and 
                         {Universidade do Vale do Para{\'{\i}}ba (UNIVAP)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {Instituto Nacional de 
                         Pesquisas Espaciais (INPE)} and {Universidade do Vale do 
                         Para{\'{\i}}ba (UNIVAP)} and {Instituto Nacional de Pesquisas 
                         Espaciais (INPE)} and {Universidade do Vale do Para{\'{\i}}ba 
                         (UNIVAP)} and {Universidade do Vale do Para{\'{\i}}ba (UNIVAP)} 
                         and {Instituto Nacional de Pesquisas Espaciais (INPE)}",
                title = "Effects of the Northern Hemisphere sudden stratospheric warmings 
                         on the Sporadic-E layers in the Brazilian sector",
              journal = "Journal of Atmospheric and Solar-Terrestrial Physics",
                 year = "2024",
               volume = "256",
                pages = "e106199",
                month = "Mar.",
             keywords = "Q2DWs periodicity, Sporadic-E layer, Sudden stratospheric warming, 
                         Tidal winds.",
             abstract = "Tidal and Planetary Wave (PWs) amplitudes are strongly influenced 
                         by Sudden Stratospheric Warming (SSW) events. A nonlinear 
                         interaction between the tidal winds and planetary waves during the 
                         SSW may contribute to the intensification of sporadic-E (Es) 
                         layers in the lower thermosphere. This work investigated the 
                         relationship between SSW events in the Northern Hemisphere and the 
                         Es layer occurrence at low latitudes in the Brazilian sector. We 
                         used data from digital ionosondes installed in the observatories 
                         of Araguatins (ARA, 5.65° S; 48.12° W; dip lat. \−5.44°) 
                         and S{\~a}o Jos{\'e} dos Campos (SJC, 23.18° S; 45.89° W; dip 
                         lat. \−21.37°) to analyze the Es layers. Additionally, we 
                         used the temperature, zonal wind, and PWs data at high latitudes 
                         in the Northern Hemisphere during the major SSW event that 
                         occurred in February/2018 and during the events of 
                         Dec/2018Jan/2019 and Dec/2020Jan/2021. The results showed a 
                         maximum frequency peak of 20 MHz (\∼5 × 106 
                         electrons.cm\−3) at ARA and SJC during these SSW events. 
                         The large values of ftEs, fbEs, and electronic densities were 
                         observed between 100 and 115 km height in the Esf/l type layers 
                         during daytime or nighttime periods. The results also showed that 
                         the number of large values of ftEs, fbEs, and electronic density 
                         of the Es layer was much higher in ARA than in SJC, in general. 
                         The wavelet power spectrum analyses of the ftEs and fbEs showed a 
                         periodicity of 2-days before and after the central day of the SSWs 
                         events at the station of ARA, with three prominent peaks in the 
                         2018/2019 event. At the SJC station the quasi-2-day periodicity in 
                         the wavelet analyses of the ftEs was observed after the central 
                         day in all three SSW events, with a peak before the central day 
                         during the 2020/2021 event.",
                  doi = "10.1016/j.jastp.2024.106199",
                  url = "http://dx.doi.org/10.1016/j.jastp.2024.106199",
                 issn = "1364-6826",
             language = "en",
           targetfile = "1-s2.0-S1364682624000270-main.pdf",
        urlaccessdate = "11 maio 2024"
}