Mesospheric 2-Day waves observed simultaneously in the equatorial and low latitudes regions of Brazil

Simultaneous observations of the atmospheric neutral winds in the mesosphere and lower thermosphere (MLT) by meteor radar have been carried out at São João do Cariri (7.4ºS, 36.5ºW) and Cachoeira Paulista (22.7ºS, 45.0ºW). From the wind variability we investigate the atmospheric planetary-scale quasi-two-day waves, which were present at both the sites during the winter of 2004 and summer of 2004/2005. The amplitude of the meridional component was larger than that of the zonal component, reaching a maximum value of ~ 60 m/s at the equatorial site and ~ 25 m/s at the low latitude site during the winter. During the January-February period the 2-day wave was very similar at the two sites, with a maximum amplitude of ~ 50 m/s. The phase propagation with height shows a descending mode and upward energy propagation. The vertical wavelength estimated for Cachoeira Paulista (40-67 km) was longer than for São João do Cariri (30-35 km), for all of the observed events. Cross-spectral analysis showed a significant coherence between the quasi-two-day oscillations observed at the two sites. From the phase difference between the two sites we concluded that São João do Cariri leads Cachoeira Paulista. These results denote that amplitude peak at 36.5ºW and subsequently at 45ºW, compatible with a westward propagating wave.

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Main Authors: Lima,Lourivaldo Mota, Medeiros,Amauri F., Buriti,Ricardo A., Batista,Paulo P., Clemesha,Barclay R., Takahashi,Hisao
Format: Digital revista
Language:English
Published: Sociedade Brasileira de Geofísica 2007
Online Access:http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0102-261X2007000600006
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spelling oai:scielo:S0102-261X20070006000062007-11-22Mesospheric 2-Day waves observed simultaneously in the equatorial and low latitudes regions of BrazilLima,Lourivaldo MotaMedeiros,Amauri F.Buriti,Ricardo A.Batista,Paulo P.Clemesha,Barclay R.Takahashi,Hisao quasi-2-day wave planetary-waves meteor radar upper mesosphere Simultaneous observations of the atmospheric neutral winds in the mesosphere and lower thermosphere (MLT) by meteor radar have been carried out at São João do Cariri (7.4ºS, 36.5ºW) and Cachoeira Paulista (22.7ºS, 45.0ºW). From the wind variability we investigate the atmospheric planetary-scale quasi-two-day waves, which were present at both the sites during the winter of 2004 and summer of 2004/2005. The amplitude of the meridional component was larger than that of the zonal component, reaching a maximum value of ~ 60 m/s at the equatorial site and ~ 25 m/s at the low latitude site during the winter. During the January-February period the 2-day wave was very similar at the two sites, with a maximum amplitude of ~ 50 m/s. The phase propagation with height shows a descending mode and upward energy propagation. The vertical wavelength estimated for Cachoeira Paulista (40-67 km) was longer than for São João do Cariri (30-35 km), for all of the observed events. Cross-spectral analysis showed a significant coherence between the quasi-two-day oscillations observed at the two sites. From the phase difference between the two sites we concluded that São João do Cariri leads Cachoeira Paulista. These results denote that amplitude peak at 36.5ºW and subsequently at 45ºW, compatible with a westward propagating wave.info:eu-repo/semantics/openAccessSociedade Brasileira de GeofísicaRevista Brasileira de Geofísica v.25 suppl.2 20072007-01-01info:eu-repo/semantics/articletext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0102-261X2007000600006en10.1590/S0102-261X2007000600006
institution SCIELO
collection OJS
country Brasil
countrycode BR
component Revista
access En linea
databasecode rev-scielo-br
tag revista
region America del Sur
libraryname SciELO
language English
format Digital
author Lima,Lourivaldo Mota
Medeiros,Amauri F.
Buriti,Ricardo A.
Batista,Paulo P.
Clemesha,Barclay R.
Takahashi,Hisao
spellingShingle Lima,Lourivaldo Mota
Medeiros,Amauri F.
Buriti,Ricardo A.
Batista,Paulo P.
Clemesha,Barclay R.
Takahashi,Hisao
Mesospheric 2-Day waves observed simultaneously in the equatorial and low latitudes regions of Brazil
author_facet Lima,Lourivaldo Mota
Medeiros,Amauri F.
Buriti,Ricardo A.
Batista,Paulo P.
Clemesha,Barclay R.
Takahashi,Hisao
author_sort Lima,Lourivaldo Mota
title Mesospheric 2-Day waves observed simultaneously in the equatorial and low latitudes regions of Brazil
title_short Mesospheric 2-Day waves observed simultaneously in the equatorial and low latitudes regions of Brazil
title_full Mesospheric 2-Day waves observed simultaneously in the equatorial and low latitudes regions of Brazil
title_fullStr Mesospheric 2-Day waves observed simultaneously in the equatorial and low latitudes regions of Brazil
title_full_unstemmed Mesospheric 2-Day waves observed simultaneously in the equatorial and low latitudes regions of Brazil
title_sort mesospheric 2-day waves observed simultaneously in the equatorial and low latitudes regions of brazil
description Simultaneous observations of the atmospheric neutral winds in the mesosphere and lower thermosphere (MLT) by meteor radar have been carried out at São João do Cariri (7.4ºS, 36.5ºW) and Cachoeira Paulista (22.7ºS, 45.0ºW). From the wind variability we investigate the atmospheric planetary-scale quasi-two-day waves, which were present at both the sites during the winter of 2004 and summer of 2004/2005. The amplitude of the meridional component was larger than that of the zonal component, reaching a maximum value of ~ 60 m/s at the equatorial site and ~ 25 m/s at the low latitude site during the winter. During the January-February period the 2-day wave was very similar at the two sites, with a maximum amplitude of ~ 50 m/s. The phase propagation with height shows a descending mode and upward energy propagation. The vertical wavelength estimated for Cachoeira Paulista (40-67 km) was longer than for São João do Cariri (30-35 km), for all of the observed events. Cross-spectral analysis showed a significant coherence between the quasi-two-day oscillations observed at the two sites. From the phase difference between the two sites we concluded that São João do Cariri leads Cachoeira Paulista. These results denote that amplitude peak at 36.5ºW and subsequently at 45ºW, compatible with a westward propagating wave.
publisher Sociedade Brasileira de Geofísica
publishDate 2007
url http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0102-261X2007000600006
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