@Article{AndrioliXBPRSFYJCWL:2020:NoSeVa,
author = "Andrioli, V{\^a}nia F{\'a}tima and Xu, Jiyao and Batista, Paulo
Prado and Pimenta, Alexandre Alvares and Resende, Laysa Cristina
de Ara{\'u}jo and Savio, Siomel and Fagundes, Paulo Roberto and
Yang, Guotao and Jiao, J. and Cheng, X. and Wang, Chi and Liu,
Z.",
affiliation = "{Chinese Academy of Sciences} 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 {Universidade do Vale do
Para{\'{\i}}ba (UNIVAP)} and {Chinese Academy of Sciences} and
{Chinese Academy of Sciences} and {Chinese Academy of Sciences}
and {Chinese Academy of Sciences} and {Chinese Academy of
Sciences}",
title = "Nocturnal and seasonal variation of Na and K layers simultaneously
observed in the MLT region at 23°S",
journal = "Journal of Geophysical Research: Space Physics",
year = "2020",
volume = "125",
number = "3",
pages = "e2019JA027164",
month = "Mar.",
abstract = "The present work shows for the first time the study of morphology
of the mesopause sodium (Na) and potassium (K) layers
simultaneously observed by a dual\‐beam LIDAR in the
Southern Hemisphere. We analyze these two alkali metal layers from
November 2016 to February 2019 measured at S{\~a}o Jos{\'e} dos
Campos (23.1°S, 45.9°W) and present their nocturnal and seasonal
behavior. The night of 25 April 2017 was investigated as a
representative of the vertical descending structure frequently
observed in the metal density data at this location. We discuss
here the chemical and dynamical contribution in the formation of
these distinct layers, using simultaneous meteor radar wind and
ionosonde data. These downward structures are seen in 66% of Na/K
LIDAR data and seem to occur preferentially around April. The good
agreement with diurnal tide and the presence of Es layer, suggest
a combining mechanism in the formation of these structures.
Moreover, semiannual variations are observed in both layers;
however, they present different maxima location. The Na density
presents its maxima around May and September; whereas, K density
shows a strong maximum around July and a weaker one around
December. Likewise, semiannual variation with maxima at the
equinoxes is observed in the centroid height for both layers.
However, the column abundances of these two metals show distinct
seasonal variation: Annual variation peaking from one equinox to
the other is observed in Na and semiannual with maxima in the
solstices in K. The same behavior of centroid height for both
layers indicates the same mechanism acting in the seasonal
variation, which is not yet completely understood.",
doi = "10.1029/2019JA027164",
url = "http://dx.doi.org/10.1029/2019JA027164",
issn = "2169-9402",
language = "en",
targetfile = "andrioli_nocturnal.pdf",
urlaccessdate = "27 abr. 2024"
}