@Article{CorreiaRaunBageDAmi:2020:ChGrWa,
               author = "Correia, Em{\'{\i}}lia and Raunheitte, Luis Tiago Medeiros and 
                         Bageston, Jos{\'e} Valentin and D'Amico, Dino Enrico",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and 
                         {Universidade Presbiteriana Mackenzie} and {Instituto Nacional de 
                         Pesquisas Espaciais (INPE)} and {Universidade Presbiteriana 
                         Mackenzie}",
                title = "Characterization of gravity waves in the lower ionosphere using 
                         very low frequency observations at Comandante Ferraz Brazilian 
                         Antarctic Station",
              journal = "Annales Geophysicae",
                 year = "2020",
               volume = "38",
               number = "2",
                pages = "385--394",
                month = "Mar.",
             abstract = "The goal of this work is to investigate the gravity wave (GW) 
                         characteristics in the low ionosphere using very low frequency 
                         (VLF) radio signals. The spatial modulations produced by the GWs 
                         affect the conditions of the electron density at reflection height 
                         of the VLF signals, which produce fluctuations of the electrical 
                         conductivity in the D region that can be detected as variations in 
                         the amplitude and phase of VLF narrowband signals. The analysis 
                         considered the VLF signal transmitted from the US Cutler, Maine 
                         (NAA) station that was received at Comandante Ferraz Brazilian 
                         Antarctic Station (EACF, 62.1\◦ S, 58.4\◦ W), with 
                         its great circle path crossing the Drake Passage longitudinally. 
                         The wave periods of the GWs detected in the low ionosphere are 
                         obtained using the wavelet analysis applied to the VLF amplitude. 
                         Here the VLF technique was used as a new aspect for monitoring GW 
                         activity. It was validated comparing the wave period and duration 
                         properties of one GW event observed simultaneously with a 
                         co-located airglow all-sky imager both operating at EACF. The 
                         statistical analysis of the seasonal variation of the wave periods 
                         detected using VLF technique for 2007 showed that the GW events 
                         occurred all observed days, with the waves with a period between 5 
                         and 10 min dominating during night hours from May to September, 
                         while during daytime hours the waves with a period between 0 and 5 
                         min are predominant the whole year and dominate all days from 
                         November to April. These results show that VLF technique is a 
                         powerful tool to obtain the wave period and duration of GW events 
                         in the low ionosphere, with the advantage of being independent of 
                         sky conditions, and it can be used during the whole day and 
                         yearround.",
                  doi = "10.5194/angeo-38-385-2020",
                  url = "http://dx.doi.org/10.5194/angeo-38-385-2020",
                 issn = "0992-7689",
             language = "en",
           targetfile = "correia_characterization.pdf",
        urlaccessdate = "27 abr. 2024"
}