@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 = "01 jun. 2024"
}