author = "Figueiredo, Cosme Alexandre Oliveira Barros and Takahashi, Hisao 
                         and Wrasse, Cristiano Max and Otsuka, Yuichi and Shiokawa, Kazuo 
                         and Silva, Diego Barros",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {Instituto Nacional de 
                         Pesquisas Espaciais (INPE)} and {Nagoya University} and {Nagoya 
                         University} and {Instituto Nacional de Pesquisas Espaciais 
                title = "Investigation of nighttime MSTIDS observed by optical thermosphere 
                         imagers at Low Latitudes: morphology, propagation direction, and 
                         wind filtering",
              journal = "Journal of Geophysical Research: Space Physics",
                 year = "2018",
               volume = "123",
               number = "9",
                pages = "7843--7857",
                month = "Sept",
             keywords = "Gravity waves, TIDs, MSTIDs, Ionoshere, Thermosphere, Airglow 
             abstract = "Different types of medium-scale traveling ionospheric disturbances 
                         (MSTIDs) have been observed at Cachoeira Paulista (22.4 degrees S; 
                         45.0 degrees W), Brazil, from June 2013 to December 2015, using 
                         airglow OI 630.0-nm images. During the period, 58 MSTIDs were 
                         identified and classified as follows: dark band MSTIDs (around 10 
                         events) and periodic MSTIDs (48 events). Dark band MSTIDs present 
                         phase velocity between 50 and 200m/s and propagation direction to 
                         northwestward. On the other hand, periodic MSTIDs have phase 
                         velocity of 50 to 200 m/s, horizontal wavelengths from 80 to 160 
                         km, periods ranging between 5 and 45 min, and propagation 
                         directions are mainly north-northeastward. The wave parameters 
                         indicate that periodic MSTIDs have different characteristics when 
                         compared to dark band MSTIDs, suggesting that periodic MSTIDs are 
                         not generated through the well-known Perkins and E-F coupling 
                         instability. In addition to it, the present study indicates that 
                         the spectral characteristics found in Brazil are different from 
                         other regions such as Japan and Indonesia. Therefore, we intend to 
                         do the statistics of the wave parameters (wavelength, phase 
                         velocity, period, propagation direction, and time occurrence) and 
                         investigate the generation mechanisms of periodic MSTIDs at low to 
                         middle latitude for the first time. Furthermore, the anisotropy 
                         observed in periodic MSTID propagation direction can be explained 
                         by different mechanisms.",
                  doi = "10.1029/2018JA025438",
                  url = "http://dx.doi.org/10.1029/2018JA025438",
                 issn = "2169-9402",
             language = "en",
           targetfile = "Figueiredo_investigation.pdf",
        urlaccessdate = "01 dez. 2020"