Wave-associated sporadic neutral layers in the upper atmosphere
Autor(a) principal: | |
---|---|
Data de Publicação: | 1997 |
Outros Autores: | , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Revista Brasileira de Geofísica (Online) |
Texto Completo: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0102-261X1997000300003 |
Resumo: | Sporadic neutral layers, with thicknesses between a few hundred meters and several kilometers, are observed by lidar in the same height range as ionospheric sporadic E. Ns layers were first observed in sodium, 20 years ago, and more recently have also been seen in potassium, iron and calcium. As in the case of Es there is a strong link with atmospheric waves, and a number of studies have shown evidence for a possible connection with tidal oscillations in the lower thermosphere. Recent observations at São José dos Campos, Brazil, have shown that sporadic sodium layers are frequently observed to occur at the heights of peaks in sodium concentration corresponding to a propagating atmospheric wave. In cases where the vertical wavelength of the propagating wave is short, as many as three complete oscillations can sometimes be seen, and the sporadic layer always occurs at the highest wave maximum, typically in the range 95-100 km. In the case of long-lived events the Ns layer is observed to accompany the downward phase propagation of the atmospheric wave. On the basis of these observations a case is made for the recombination of sodium ions as the source of the observed sporadic layers. |
id |
SBG-3_9675e668e8412aae1019952b4a27215a |
---|---|
oai_identifier_str |
oai:scielo:S0102-261X1997000300003 |
network_acronym_str |
SBG-3 |
network_name_str |
Revista Brasileira de Geofísica (Online) |
repository_id_str |
|
spelling |
Wave-associated sporadic neutral layers in the upper atmosphereNsEsSporadic layersSporadic-ESodiumSporadic neutral layers, with thicknesses between a few hundred meters and several kilometers, are observed by lidar in the same height range as ionospheric sporadic E. Ns layers were first observed in sodium, 20 years ago, and more recently have also been seen in potassium, iron and calcium. As in the case of Es there is a strong link with atmospheric waves, and a number of studies have shown evidence for a possible connection with tidal oscillations in the lower thermosphere. Recent observations at São José dos Campos, Brazil, have shown that sporadic sodium layers are frequently observed to occur at the heights of peaks in sodium concentration corresponding to a propagating atmospheric wave. In cases where the vertical wavelength of the propagating wave is short, as many as three complete oscillations can sometimes be seen, and the sporadic layer always occurs at the highest wave maximum, typically in the range 95-100 km. In the case of long-lived events the Ns layer is observed to accompany the downward phase propagation of the atmospheric wave. On the basis of these observations a case is made for the recombination of sodium ions as the source of the observed sporadic layers.Sociedade Brasileira de Geofísica1997-11-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0102-261X1997000300003Revista Brasileira de Geofísica v.15 n.3 1997reponame:Revista Brasileira de Geofísica (Online)instname:Sociedade Brasileira de Geofísica (SBG)instacron:SBG10.1590/S0102-261X1997000300003info:eu-repo/semantics/openAccessClemesha,B. R.Batista,P. P.Simonich,D. M.eng2001-06-08T00:00:00Zoai:scielo:S0102-261X1997000300003Revistahttp://www.scielo.br/rbgONGhttps://old.scielo.br/oai/scielo-oai.php||sbgf@sbgf.org.br1809-45110102-261Xopendoar:2001-06-08T00:00Revista Brasileira de Geofísica (Online) - Sociedade Brasileira de Geofísica (SBG)false |
dc.title.none.fl_str_mv |
Wave-associated sporadic neutral layers in the upper atmosphere |
title |
Wave-associated sporadic neutral layers in the upper atmosphere |
spellingShingle |
Wave-associated sporadic neutral layers in the upper atmosphere Clemesha,B. R. Ns Es Sporadic layers Sporadic-E Sodium |
title_short |
Wave-associated sporadic neutral layers in the upper atmosphere |
title_full |
Wave-associated sporadic neutral layers in the upper atmosphere |
title_fullStr |
Wave-associated sporadic neutral layers in the upper atmosphere |
title_full_unstemmed |
Wave-associated sporadic neutral layers in the upper atmosphere |
title_sort |
Wave-associated sporadic neutral layers in the upper atmosphere |
author |
Clemesha,B. R. |
author_facet |
Clemesha,B. R. Batista,P. P. Simonich,D. M. |
author_role |
author |
author2 |
Batista,P. P. Simonich,D. M. |
author2_role |
author author |
dc.contributor.author.fl_str_mv |
Clemesha,B. R. Batista,P. P. Simonich,D. M. |
dc.subject.por.fl_str_mv |
Ns Es Sporadic layers Sporadic-E Sodium |
topic |
Ns Es Sporadic layers Sporadic-E Sodium |
description |
Sporadic neutral layers, with thicknesses between a few hundred meters and several kilometers, are observed by lidar in the same height range as ionospheric sporadic E. Ns layers were first observed in sodium, 20 years ago, and more recently have also been seen in potassium, iron and calcium. As in the case of Es there is a strong link with atmospheric waves, and a number of studies have shown evidence for a possible connection with tidal oscillations in the lower thermosphere. Recent observations at São José dos Campos, Brazil, have shown that sporadic sodium layers are frequently observed to occur at the heights of peaks in sodium concentration corresponding to a propagating atmospheric wave. In cases where the vertical wavelength of the propagating wave is short, as many as three complete oscillations can sometimes be seen, and the sporadic layer always occurs at the highest wave maximum, typically in the range 95-100 km. In the case of long-lived events the Ns layer is observed to accompany the downward phase propagation of the atmospheric wave. On the basis of these observations a case is made for the recombination of sodium ions as the source of the observed sporadic layers. |
publishDate |
1997 |
dc.date.none.fl_str_mv |
1997-11-01 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0102-261X1997000300003 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0102-261X1997000300003 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
10.1590/S0102-261X1997000300003 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
text/html |
dc.publisher.none.fl_str_mv |
Sociedade Brasileira de Geofísica |
publisher.none.fl_str_mv |
Sociedade Brasileira de Geofísica |
dc.source.none.fl_str_mv |
Revista Brasileira de Geofísica v.15 n.3 1997 reponame:Revista Brasileira de Geofísica (Online) instname:Sociedade Brasileira de Geofísica (SBG) instacron:SBG |
instname_str |
Sociedade Brasileira de Geofísica (SBG) |
instacron_str |
SBG |
institution |
SBG |
reponame_str |
Revista Brasileira de Geofísica (Online) |
collection |
Revista Brasileira de Geofísica (Online) |
repository.name.fl_str_mv |
Revista Brasileira de Geofísica (Online) - Sociedade Brasileira de Geofísica (SBG) |
repository.mail.fl_str_mv |
||sbgf@sbgf.org.br |
_version_ |
1754820935861403648 |