Produção Nacional
Analysis of storm-time low-latitude simultaneous ionospheric and nightglow emission measurements
1990; Elsevier BV; Volume: 52; Issue: 9 Linguagem: Inglês
10.1016/0021-9169(90)90007-a
ISSN1878-593X
AutoresY. Sahai, J. A. Bittencourt, H. Takahashi, N. R. Teixeira, Brian A. Tinsley, R. P. Rohrbaugh,
Tópico(s)Earthquake Detection and Analysis
ResumoThe first simultaneous ground-based observations of the permitted atomic oxygen OI 777.4 nm emission line and the forbidden OI 630.0 and 557.7 nm emission lines have been carried out from Cachoeira Paulista (22.7°S, 45.0°W) and Fortaleza (3.9°S, 38.4°W), Brazil, during the period November 1986–March 1988. In addition, N2+ 391.4 nm emission observations have been carried out at Cachoeira Paulista during the same period. At both stations ionosonde measurements are carried out on a routine basis. These simultaneous multispectral optical and ionospheric measurements have made possible studies on the response of the equatorial and low-latitude ionospheric F-region to magnetic storms. A comparison of the observations obtained during magnetically quiet and disturbed conditions shows that the nocturnal intensity variations of the atomic oxygen emissions observed are well correlated with the variations of the F-region parameters (ƒ0F2 and h'F), showing the dominant role played by the enhanced F-region dynamical processes during disturbed periods, possibly induced by substorm-associated electric fields and disturbed neutral winds in the low-latitude F-region. While the N2+ emission is enhanced in disturbed periods, as expected from energetic neutral particle precipitation, any enhancements in the atomic oxygen emissions were not detectable against the airglow due to recombination processes.
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