author = "Medeiros, Amauri Fragoso de and Buriti, R A and Machado, E A and 
                         Takahashi, Hisao and Batista, Paulo Prado and Gobbi, Delano and 
                         Taylor, M J",
          affiliation = "Universidade Federal de Campina Grande, Departamento de 
                         F{\'{\i}}sica and INPE and Space Dynamics Laboratory and Physics 
                         Department, Utah State University",
                title = "Comparison of gravity wave activity observed by airglow imaging at 
                         two different latitudes in Brazil",
              journal = "Journal of Atmospheric and Solar-Terrestrial Physics",
                 year = "2004",
               volume = "66",
               number = "6-9",
                pages = "647--654",
                month = "Apr-Jun.",
             keywords = "Gravity wave, airglow, imager, winds.",
             abstract = "An all-sky CCD imager for the OH, O2 and OI (557.7 nm) airglow 
                         emissions was operated at Cachoeira Paulista (CP), Brazil (23 S, 
                         45 W), in collaboration with Utah State University, USA, during 
                         the period of 1998-2000. Another all-sky imager, which belongs to 
                         the Instituto Nacional de Pesquisas Espaciais, has been operating 
                         at S{\~a}o Jo{\~a}o do Cariri (Cariri), Brazil (7 S, 36 W) since 
                         October 2000. Dominant gravity wave components were investigated 
                         by using the image data from the two sites. Wave characteristics 
                         observed at CP (October 1998-September 1999) show horizontal 
                         wavelenghts of 5-60 km, periods of 5-35 min and horizontal phase 
                         velocities of 1-80 m/s. Band-type waves (horizontal wavelenghts 
                         between 10 and 85 km) showed a clear seasonal dependeney in the 
                         horizontal propagation direction, propagating to the southeast in 
                         summer and to the northwest in winter. The Cariri data (September 
                         2000-August 2001) showed horizontal wavelenghts of 5-65 km, with 
                         periods of 5-55 min and horizontal phase velocities of 5-105 m/s, 
                         much higher than CP. Band-type waves also exhibited a seasonal 
                         dependency in the horizontal propagation direction, propagation to 
                         southeast in summer and northeast in winter.The results are 
                         interpreted in terms of wind filtering and a non-uniform 
                         distribution of the gravity wave sources.",
           copyholder = "SID/SCD",
            isbn/issn = "1364-6826",
                 issn = "1364-6826",
             language = "en",
           targetfile = "comparison of gravity.pdf",
        urlaccessdate = "28 jan. 2021"