Equatorial F-region irregularities generated by the Rayleigh-Taylor instability mechanism: rocket observations from Brazil
Autor(a) principal: | |
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Data de Publicação: | 2007 |
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=S0102-261X2007000600016 |
Resumo: | Several sounding rockets carrying plasma diagnostic experiments were launched from the Brazilian rocket launching stations in Natal (5.9ºS, 35.2ºW Geog. Lat.) and Alcântara (2.31ºS, 44.4ºW Geog. Lat.). Langmuir Probes (LP) were used to measure the height profiles of electron density and electron temperature and High Frequency Capacitance (HFC) probes were used to measure electron density. The LP's were also used to measure the amplitude of electron density fluctuations. A detailed study of the characteristic features of electron density irregularities in the scale size range of less than a meter to a few kilometres, observed by rocket-borne electron density probes under different ionospheric conditions is presented here. The main objective of these studies is the identification of these irregularities from the point of view of the dynamic and electrodynamic processes responsible for their generation. The existing theories of the Rayleigh Taylor Instability (RTI) mechanism applicable for conditions of the geomagnetic equatorial ionosphere over Brazil are critically examined in the light of the observations. The observed characteristics of the irregularities during four rocket launches are compared with the theoretically expected characteristics. These results confirm the operation of a cascade process that is responsible for the generation of a wide spectrum of irregularities. The large-scale irregularities are first generated probably by the RTI mechanism that creates conditions favourable for the operation of the Cross-Field (CFI) or the Gradient Drift Instability (GDI) mechanism. From the k-spectra of irregularities it is possible to obtain the spectral index n corresponding to the height chosen. In most of the cases the estimated spectral indices agree well with those published in the literature for the cases of irregularities generated by the GDI mechanism. |
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Equatorial F-region irregularities generated by the Rayleigh-Taylor instability mechanism: rocket observations from Brazilspace plasmaionosphereF-regionRayleigh-Taylor instabilityCross-Field instabilitySeveral sounding rockets carrying plasma diagnostic experiments were launched from the Brazilian rocket launching stations in Natal (5.9ºS, 35.2ºW Geog. Lat.) and Alcântara (2.31ºS, 44.4ºW Geog. Lat.). Langmuir Probes (LP) were used to measure the height profiles of electron density and electron temperature and High Frequency Capacitance (HFC) probes were used to measure electron density. The LP's were also used to measure the amplitude of electron density fluctuations. A detailed study of the characteristic features of electron density irregularities in the scale size range of less than a meter to a few kilometres, observed by rocket-borne electron density probes under different ionospheric conditions is presented here. The main objective of these studies is the identification of these irregularities from the point of view of the dynamic and electrodynamic processes responsible for their generation. The existing theories of the Rayleigh Taylor Instability (RTI) mechanism applicable for conditions of the geomagnetic equatorial ionosphere over Brazil are critically examined in the light of the observations. The observed characteristics of the irregularities during four rocket launches are compared with the theoretically expected characteristics. These results confirm the operation of a cascade process that is responsible for the generation of a wide spectrum of irregularities. The large-scale irregularities are first generated probably by the RTI mechanism that creates conditions favourable for the operation of the Cross-Field (CFI) or the Gradient Drift Instability (GDI) mechanism. From the k-spectra of irregularities it is possible to obtain the spectral index n corresponding to the height chosen. In most of the cases the estimated spectral indices agree well with those published in the literature for the cases of irregularities generated by the GDI mechanism.Sociedade Brasileira de Geofísica2007-01-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0102-261X2007000600016Revista Brasileira de Geofísica v.25 suppl.2 2007reponame:Revista Brasileira de Geofísica (Online)instname:Sociedade Brasileira de Geofísica (SBG)instacron:SBG10.1590/S0102-261X2007000600016info:eu-repo/semantics/openAccessMuralikrishna,PolinayaVieira,Leandro Paulinoeng2007-11-22T00:00:00Zoai:scielo:S0102-261X2007000600016Revistahttp://www.scielo.br/rbgONGhttps://old.scielo.br/oai/scielo-oai.php||sbgf@sbgf.org.br1809-45110102-261Xopendoar:2007-11-22T00:00Revista Brasileira de Geofísica (Online) - Sociedade Brasileira de Geofísica (SBG)false |
dc.title.none.fl_str_mv |
Equatorial F-region irregularities generated by the Rayleigh-Taylor instability mechanism: rocket observations from Brazil |
title |
Equatorial F-region irregularities generated by the Rayleigh-Taylor instability mechanism: rocket observations from Brazil |
spellingShingle |
Equatorial F-region irregularities generated by the Rayleigh-Taylor instability mechanism: rocket observations from Brazil Muralikrishna,Polinaya space plasma ionosphere F-region Rayleigh-Taylor instability Cross-Field instability |
title_short |
Equatorial F-region irregularities generated by the Rayleigh-Taylor instability mechanism: rocket observations from Brazil |
title_full |
Equatorial F-region irregularities generated by the Rayleigh-Taylor instability mechanism: rocket observations from Brazil |
title_fullStr |
Equatorial F-region irregularities generated by the Rayleigh-Taylor instability mechanism: rocket observations from Brazil |
title_full_unstemmed |
Equatorial F-region irregularities generated by the Rayleigh-Taylor instability mechanism: rocket observations from Brazil |
title_sort |
Equatorial F-region irregularities generated by the Rayleigh-Taylor instability mechanism: rocket observations from Brazil |
author |
Muralikrishna,Polinaya |
author_facet |
Muralikrishna,Polinaya Vieira,Leandro Paulino |
author_role |
author |
author2 |
Vieira,Leandro Paulino |
author2_role |
author |
dc.contributor.author.fl_str_mv |
Muralikrishna,Polinaya Vieira,Leandro Paulino |
dc.subject.por.fl_str_mv |
space plasma ionosphere F-region Rayleigh-Taylor instability Cross-Field instability |
topic |
space plasma ionosphere F-region Rayleigh-Taylor instability Cross-Field instability |
description |
Several sounding rockets carrying plasma diagnostic experiments were launched from the Brazilian rocket launching stations in Natal (5.9ºS, 35.2ºW Geog. Lat.) and Alcântara (2.31ºS, 44.4ºW Geog. Lat.). Langmuir Probes (LP) were used to measure the height profiles of electron density and electron temperature and High Frequency Capacitance (HFC) probes were used to measure electron density. The LP's were also used to measure the amplitude of electron density fluctuations. A detailed study of the characteristic features of electron density irregularities in the scale size range of less than a meter to a few kilometres, observed by rocket-borne electron density probes under different ionospheric conditions is presented here. The main objective of these studies is the identification of these irregularities from the point of view of the dynamic and electrodynamic processes responsible for their generation. The existing theories of the Rayleigh Taylor Instability (RTI) mechanism applicable for conditions of the geomagnetic equatorial ionosphere over Brazil are critically examined in the light of the observations. The observed characteristics of the irregularities during four rocket launches are compared with the theoretically expected characteristics. These results confirm the operation of a cascade process that is responsible for the generation of a wide spectrum of irregularities. The large-scale irregularities are first generated probably by the RTI mechanism that creates conditions favourable for the operation of the Cross-Field (CFI) or the Gradient Drift Instability (GDI) mechanism. From the k-spectra of irregularities it is possible to obtain the spectral index n corresponding to the height chosen. In most of the cases the estimated spectral indices agree well with those published in the literature for the cases of irregularities generated by the GDI mechanism. |
publishDate |
2007 |
dc.date.none.fl_str_mv |
2007-01-01 |
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=S0102-261X2007000600016 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0102-261X2007000600016 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
10.1590/S0102-261X2007000600016 |
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.25 suppl.2 2007 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_ |
1754820936878522368 |