@Article{MoroXDRSLLYWS:2019:SoIoVa,
author = "Moro, Juliano and Xu, J and Denardin, Clezio Marcos and Resende,
Laysa Cristina Ara{\'u}jo and Silva, R{\'e}gia Pereira da and
Liu, Z. and Li, H. and Yan, C. and Wang, C. and Schuch, Nelson
Jorge",
affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Chinese
Academy of Sciences (CAS)} and {Instituto Nacional de Pesquisas
Espaciais (INPE)} and {} and {Instituto Nacional de Pesquisas
Espaciais (INPE)} and {} and {Chinese Academy of Sciences (CAS)}
and {Chinese Academy of Sciences (CAS)} and {Chinese Academy of
Sciences (CAS)} and {Instituto Nacional de Pesquisas Espaciais
(INPE)}",
title = "On the Sources of the Ionospheric Variability in the South
American Magnetic Anomaly During Solar Minimum",
journal = "Journal of Geophysical Research: Space Physics",
year = "2019",
volume = "124",
pages = "1",
abstract = "t We investigate for the first time the variability of the F2
layer critical frequency (foF2), its peak height (hmF2), the
thickness parameter B0, and the E region critical frequency (foE)
over Santa Maria (29.7° S, 53.7° W, dip angle = \−37°), a
station located in the central region of the South American
Magnetic Anomaly. The selected ionospheric parameters were
obtained from ionograms recorded by a recent Digisonde Portable
Sounder 4\‐D. The time period covers 309 days from 1
September 2017 to 30 August 2018. The diurnal analyses revealed a
large day\‐to\‐day ionospheric variability, with
some peculiarities as a strong semiannual pattern superimposed to
expected ionospheric behavior. Furthermore, the results show
significant differences between the averaged foF2 in December and
June solstices, revealing a possible presence of the annual
asymmetry. The coefficient of variation (CV) is used as a
quantitative description of the variability of each parameter
versus time and season. Considering low solar flux and
geomagnetically quiet days only, we note that CV is smaller during
the daytime and larger during nighttime for all parameters. The
least variable ionospheric parameter in our study is foE, while
the most variable one is B0. Regarding the F2 layer parameters, we
observe that foF2 is much more variable than hmF2. We attribute
the observed CV to the neutral atmosphere source over Santa Maria.
The ionospheric variability is in general enhanced during
geomagnetically disturbed periods. The estimated CV is higher over
Santa Maria than Wuhan, China (30.5° N, 114.4° E, dip angle =
46°), a station with no influence of the South American Magnetic
Anomaly.",
doi = "10.1029/2019ja026780",
url = "http://dx.doi.org/10.1029/2019ja026780",
issn = "2169-9402",
label = "lattes: 0549130828972280 10 MoroXNRSLLYWS:2019:SoIoVa",
language = "en",
targetfile = "moro_sources.pdf",
urlaccessdate = "29 mar. 2024"
}