author = "Bilibio, Anderson Vestena and Wrasse, Cristiano Max and 
                         Figueiredo, Cosme Alexandre Oliveira Barros and Schuch, Nelson 
                         Jorge and Paulino, I. and Takahashi, Hisao",
          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)} and {Universidade Federal de Campina Grande 
                         (UFCG)} and {Instituto Nacional de Pesquisas Espaciais (INPE)}",
                title = "Medium-scale gravity waves observed in the airglow over Cachoeira 
                 year = "2018",
         organization = "Latin American Conference on Space Geophysics, 11. (COLAGE)",
             abstract = "Medium-scale gravity waves were observed in the mesosphere and 
                         lower thermosphere region between 1998 and 2013 at the Observatory 
                         of Cachoeira Paulista, SP, (22.4oS; 45.0oO). Images obtained from 
                         OH and OI (557.7 nm) airglow emissions were used to investigate 
                         the wave characteristics, using the keograma technique. The 
                         results showed that 142 gravity wave events observed in the 
                         airglow emission have the following characteristics: horizontal 
                         wavelength between 50 and 500 km, observed period between 20 and 
                         80 minutes, phase velocity between 40 and 100 m/s. Medium-scale 
                         gravity wave propagation directions were analyzed for each season 
                         of the year and presented the following propagation 
                         characteristics: summer propagation to Northeast and Southeast, 
                         autumn mainly propagation to Northwest, winter showed a 
                         quasi-isotropic propagation and during spring the waves propagated 
                         to Northeast and Southeast. A comparison of the propagation 
                         directions between small and medium scale gravity wave was also 
                         performed. The mainly propagation directions of small and 
                         medium-scale gravity waves are similar for each season of the 
                         year. This may indicate that the possible wave sources of 
                         medium-scale gravity wave may be related to the same 
                         meteorological phenomena that generate small-scale gravity waves 
                         over Cachoeira Paulista, such as frontal systems and convective 
  conference-location = "Buenos Aires, Argentina",
      conference-year = "16-20 abr.",
             language = "en",
        urlaccessdate = "15 jan. 2021"