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BIBTEX RIS

Characterization of medium-scale traveling ionospheric disturbances in the brazilian low latitude sector – Statistical Analysis of All-Sky Images of oi 630 nm airglow emission

2012; Brazilian Society of Geophysics; Volume: 30; Issue: 2 Linguagem: Inglês

10.22564/rbgf.v30i2.86

ISSN

1809-4511

Autores

Danielle Cristina de Morais Amorim, A. A. Pimenta, Aline Amorim de Almeida,

Tópico(s)

Solar and Space Plasma Dynamics

Resumo

In order to characterize the phenomenon known as Medium-Scale Traveling Ionospheric Disturbances (MSTIDs), we present in this paper the resultsobtained from the statistical analysis of 10.5 years all-sky images of OI 630 nm airglow emission over the Brazilian low latitude sector. The images, which were obtainedby an all-sky imager installed at Cachoeira Paulista (22.7◦S, 45◦W), show dark band structures propagating from southeast to northwest with velocities of 50-200 m/s.Our results show the greatest occurrence of MSTIDs during solar minimum and a minor occurrence rate during descending and ascending solar activity periods. Duringsolar maximum activity we have not detected MSTIDs signatures on all-sky images. In relation to seasonality, the greatest frequency of occurrence is during local winter.All detected events have occurred during geomagnetically quiet conditions (Kp<3). Possible mechanisms of generation of this phenomenon are discussed.

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