@Article{CandidoSBBCAMBCWL:2019:CaSt,
author = "Candido, Cl{\'a}udia Maria Nicoli and Shi, Jiankui and Batista,
Inez Staciarini and Becker Guedes, F{\'a}bio and Correia,
Em{\'{\i}}lia and Abdu, Mangalathayil Ali and Makela, Jonathan
and Balan, Nanan and Chapagain, Narayan and Wang, Chi and Liu,
Zhengkuan",
affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Chinese
Academy of Sciences} and {Instituto Nacional de Pesquisas
Espaciais (INPE)} and {Instituto Nacional de Pesquisas Espaciais
(INPE)} and {Instituto Nacional de Pesquisas Espaciais (INPE)} and
{Instituto Nacional de Pesquisas Espaciais (INPE)} and {University
of Illinois at Urbana–Champaign} and {Chinese Academy of Sciences}
and {Tribhuvan University} and {Chinese Academy of Sciences} and
{Chinese Academy of Sciences}",
title = "Postmidnight equatorial plasma irregularities on the June solstice
during low solar activity - a case study",
journal = "Annales Geophysicae",
year = "2019",
volume = "37",
number = "4",
pages = "657--672",
month = "July",
abstract = "We present a case study of unusual spread-F structures observed by
ionosondes at two equatorial and low-latitude Brazilian stations -
Sao Luis (SL: 44.2 degrees W, 2.33 degrees S; dip angle: -6.9
degrees) and Fortaleza (FZ: 38.45 degrees W, 3.9 degrees S; dip
angle: -16 degrees). The irregularity structures observed from
midnight to postmidnight hours of moderate solar activity (F10.7 <
97 sfu, where 1 sfu = 10(-22) W m(-2) s(-1)) have characteristics
different from typical post-sunset equatorial spread F. The
spread-F traces first appeared at or above the F-layer peak and
gradually became well-formed mixed spread F. They also appeared as
plasma depletions in the 630.0 nm airglow emissions made by a
wide-angle imager located at the nearby low-latitude station
Cajazeiras (CZ: 38.56 degrees W, 6.87 degrees S; dip angle: -21.4
degrees). The irregularities appeared first over FZ and later over
SL, giving evidence of an unusual westward propagation or a
horizontal plasma advection. The drift-mode operation available in
one of the ionosondes (a digital portable sounder, DPS-4) has
enabled us to analyze the horizontal drift velocities and
directions of the irregularity movement. We also analyzed the
neutral wind velocity measured by a Fabry-Perot interferometer
(FPI) installed at CZ and discuss its possible role in the
development of the irregularities.",
doi = "10.5194/angeo-37-657-2019",
url = "http://dx.doi.org/10.5194/angeo-37-657-2019",
issn = "0992-7689",
language = "en",
targetfile = "candido_postmi.pdf",
urlaccessdate = "21 maio 2024"
}