Produção Nacional
Observations of gravity waves from multispectral mesospheric nightglow emissions observed at 23°S
1995; Elsevier BV; Volume: 57; Issue: 4 Linguagem: Inglês
10.1016/0021-9169(94)e0007-a
ISSN1878-593X
AutoresP. R. Fagundes, H. Takahashi, Y. Sahai, D. Gobbi,
Tópico(s)GNSS positioning and interference
ResumoAbstract Simultaneous measurements of the 015 57.7 nm, O2 atmospheric (0,1) band, NaD and OH (9,4) band emissions obtained during the period October November 1989 at Cachoeira Paulista (23°S, 45°W), Brazil, have been analysed to study gravity waves in the mesospheric region at a low-latitude station in the southern hemisphere. It was found that, when these emissions showed large temporal intensity variations, there were also short period quasi-coherent temporal variations superposed on them, suggesting a possible passage of internal gravity waves in the emission layers. Cross-correlation analysis indicates that the time lag between the different emissions is smaller for short period variations compared with the long period variations. The wave parameters, namely a vertical wavelength of 12 km, a horizontal derived wavelength of 200 km with a period of 80 min, estimated from one of the observed short-period coherent oscillations, are typical of the internal gravity waves at the airglow emission height.
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