@InProceedings{EgitoBuriBatiPanc:2021:LoVaNo,
               author = "Egito, F. and Buriti, R. A. and Batista, Paulo Prado and Pancheva, 
                         D.",
          affiliation = "{Universidade Federal do Rec{\^o}ncavo da Bahia} and 
                         {Universidade Federal de Campina Grande (UFCG)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {Bulgarian Academy of 
                         Sciences}",
                title = "Longitudinal variability of the nonlinear interaction between 
                         ultrafast Kelvin waves and diurnal tides",
                 year = "2021",
         organization = "Simp{\'o}sio Brasileiro de Geof{\'{\i}}sica Espacial e 
                         Aeronomia, 8. (SBGEA)",
             abstract = "The nonlinear interaction between tides and planetary scale waves 
                         contributes to the short-term variability of the MLT dynamics and 
                         is a pathway for the coupling between the neutral atmosphere and 
                         the ionosphere-thermosphere (I-T) system. By using MLT wind 
                         measurements carried out at Cariri (7.4oS, 36.5oW) and at 
                         Ascension Island (7.9oS, 14.4oW) we have investigated the 
                         nonlinear interaction between an ultrafast Kelvin wave (UFKW) and 
                         the diurnal tide. Along with the signature of an UFKW 
                         (\∼0.25 cycle/day), we observed periodic oscillations in 
                         the zonal wind, at both Cariri and Ascension Island, consistent 
                         with the secondary waves generated via the nonlinear interaction 
                         between the UFKW and the diurnal tide (1 cycle/day). In addition, 
                         we observed the modulation of the diurnal tide amplitude in the 
                         zonal wind at the period of the UFKW. At Cariri only the 0.75 
                         cycle/day secondary wave related to the difference between the 
                         frequencies of the diurnal tide (1 cycle/day) and the UFKW was 
                         observed. On the other hand, at Ascension, both secondary waves 
                         related to the sum (1.25 cycle/day) and difference (0.75 
                         cycle/day) between the diurnal tide and UFKW frequencies were 
                         observed. The vertical structure of these periodic oscillations 
                         also exhibited distinct behavior. At Cariri, the 0.75 cycle/day 
                         secondary wave exhibited a well-defined vertical structure with 
                         downward phase progression, indicating upward propagation with 
                         vertical wavelength of 44 km. On the other hand, at Ascension, 
                         while the 0.75 cycle/day secondary wave did not exhibit clear 
                         phase progression, either downward or upward, the 1.25 cycle/day 
                         secondary wave exhibited downward phase progression, and then 
                         upward propagation, with vertical wavelength of approximately 20 
                         km. In this paper we will present and discuss in more details the 
                         characteristics and possible impacts of the nonlinear interaction 
                         in the mesosphere-thermosphere-ionosphere system.",
  conference-location = "Online",
      conference-year = "22-26 mar.",
             language = "en",
        urlaccessdate = "03 maio 2024"
}