@InProceedings{BertoniLiFaSaPiBeAb:2006:ObAtGr,
               author = "Bertoni, F. and Lima, W. and Fagundes, Paulo Roberto and Sahai, Y. 
                         and Pillat, V. and Becker-Guedes, F. and Abalde, Jos{\'e} 
                         Ricardo",
          affiliation = "Center for Atmospheric and Space Physics, Centro 
                         Universit{\'a}rio Luterano de Palmas and Center for Atmospheric 
                         and Space Physics, Centro Universit{\'a}rio Luterano de Palmas 
                         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 
                         {Universidade do Vale do Para{\'{\i}}ba (UNIVAP)} and 
                         {Universidade do Vale do Para{\'{\i}}ba (UNIVAP)}",
                title = "Observations of atmospheric gravity waves near equatorial region 
                         and its relationship with the F2-layer stratification",
            booktitle = "Proceedings...",
                 year = "2006",
         organization = "Committe on Space Research, 36. (COSPAR).",
             abstract = "Atmospheric gravity waves (AGWs) can be generated by different 
                         sources: During geomagnetic disturbances (e.g. Joule heating by 
                         particle precipitations at high latitudes) and tropospheric 
                         disturbances (e.g. cold fronts, lightning etc.). When such 
                         wave-like disturbances propagate through the atmosphere, either 
                         horizontally or vertically, they can be observed in ionospheric 
                         sounding observations, in the form of the traveling ionospheric 
                         disturbances (TIDs). A digital ionosonde located at Palmas 
                         (10.16°S, 48.2°W, dip 11), Brazil, operates in two distinct modes: 
                         in the first one frequencies between 1 and 20 MHz are swept 
                         (generating the well known ionograms every 5 min.), in the second 
                         one ionospheric soundings are carried out at six fixed frequencies 
                         (3, 4, 5, 6, 7 and 8 MHz) with high time resolution (100 sec.). 
                         Using the second mode, it is possible to observe the temporal 
                         variations of the height changes for different sounding 
                         frequencies (iso-frequency plots). Such plots make possible to 
                         observe the presence or absence of the AGWs. An analysis of 
                         observations on several geomagnetically quiet days in December 
                         2003, January 2004 and February 2004 showed some evidences of the 
                         presence of AGWs, possibly associated with tropospheric 
                         disturbances, just before the occurrence of stratification of the 
                         F2-layer (generating an additional F3-layer), suggesting some 
                         relation between them. In this work, we present results and 
                         discuss the possibility of inter-relation between the occurrence 
                         of AGW and stratification of the F2-layer.",
  conference-location = "Beijing, China",
      conference-year = "2006-07-16",
                label = "self-archiving-INPE-MCTIC-GOV-BR",
             language = "en",
           targetfile = "bertoni_observations.pdf",
        urlaccessdate = "19 maio 2024"
}