@Article{SantanaSobrTakaTayl:2001:OpStIo,
author = "Santana, Daniela Cristina and Sobral, Jos{\'e} Humberto Andrade
and Takahashi, Hisao and Taylor, Michael J.",
title = "Optical studies of the ionospheric irregularities over the
Brazilian region by nocturnal images of the OI 630 nm emission",
journal = "Advances in Space Research",
year = "2001",
volume = "27",
number = "6-7",
pages = "1207--1212",
keywords = "AERONOMIA, Brasil, bolhas de plasma, ionosf{\'e}ricas,
irregularidades, aeroluminesc{\^e}ncia, imagnes, plasma bubbles,
ionospherics, irregularities, airglow, images.",
abstract = "This study is an extension of previous statistical studies (Sobral
et al., 1990,1991,1999)of both the local time and latitude
variations of the zonal drift velocities of ionospheric plasma
depletions, over the Brazilian low latitude station Cachoeira
Paulista - CP (22.54 degreesS, 45.00 degreesW). The past studies
were based on OI 630 nm scanning photometer data and the present
one is based on digital OI 630 nm airglow images obtained by an
all-sky imager system. These data were gathered between October
1998 and October 1999, at CP. The present results show that, in
general, the velocities clearly tended to decrease with local
time. Such a decrease should be associated with decreasing
intensity of the vertical component of the ambient electric field
which, in turn can be accounted for by recombination. All zonal
drifts obtained for the 18 nights were eastwards. During equinox,
the velocities clearly tended to decrease with local time at lower
rates as compared with spring and summer. The highest and lowest
zonal drift velocities, from all three seasons considered here,
were observed to be in the summer similar to 180 ms(-1)at 21:45
LT, and in the spring similar to 25 ms(-1)at 03:15 LT,
respectively. Ionospheric plasma bubbles were detected out to the
maximum extra-tropical geographical latitude of similar to 28
degreesS, which was the highest latitude position analyzed in this
study.",
issn = "0273-1177",
label = "9755",
language = "en",
targetfile = "1-s2.0-S0273117701001995-main.pdf",
urlaccessdate = "10 maio 2024"
}