@Article{RodriguesZMFPCSB:2019:SyDeSp,
author = "Rodrigues, Fabiano da Silveira and Zhan, Weijia and Milla, Marco
A. and Fejer, Bela G. and Paula, Eurico Rodrigues de and Cunha
Neto, Ac{\'a}cio and Santos, Angela Machado dos and Batista, Inez
Staciarini",
affiliation = "{The University of Texas at Dallas} and {The University of Texas
at Dallas} and {Instituto Geofisicio del Peru} and {Utah State
University} 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)}",
title = "MELISSA: System description and spectral features of pre- and
post-midnight F-region echoes",
journal = "Journal of Geophysical Research: Space Physics",
year = "2019",
volume = "2019",
keywords = "equatorial, irregularities, ionosphere, radar, spread F.",
abstract = "Most of the low-latitude ionospheric radar observations in South
America come from the Jicamarca Radio Observatory, located in the
western longitude sector (similar to 75 degrees W). The deployment
of the 30 MHz FAPESP-Clemson-INPE (FCI) coherent backscatter radar
in the magnetic equatorial site of Sao Luis, Brazil, in 2001
allowed observations to be made in the eastern sector (similar to
45 degrees W). However, despite being operational for several
years (2001-2012), FCI only made observations during daytime and
pre-midnight hours, with a few exceptions. Here, we describe an
upgraded system that replaced the FCI radar and present results of
full-night F-region observations. This radar is referred to as
Measurements of Equatorial and Low-latitude Ionospheric
irregularities over Sao Luis, South America (MELISSA), and made
observations between March 2014 and December 2018. We present
results of our analyses of pre- and post-midnight F-region echoes
with focus on the spectral features of post-midnight echoes and
how they compare to spectra of echoes observed in the post-sunset
sector. The radar observations indicate that post-midnight
F-region irregularities were generated locally and were not a
result of {"}fossil{"} structures generated much earlier in time
(in other longitude sectors) and that drifted into the radar
field-of-view. This also includes cases where the echoes are weak
and that would be associated with decaying equatorial spread F
(ESF) structures. Collocated digisonde observations show modest
but noticeable F-region apparent uplifts prior to post-midnight
ESF events. We associate the equatorial uplifts with disturbed
dynamo effects and with destabilizing F-region conditions leading
to ESF development.",
doi = "10.1029/2019JA027445",
url = "http://dx.doi.org/10.1029/2019JA027445",
issn = "2169-9402",
language = "en",
targetfile = "rodrigues_melissa.pdf",
urlaccessdate = "03 jun. 2024"
}