Deviations from model predictions in measured electron density profiles for low latitudes: A critique

In situ electron density profiles obtained from equatorial stations in Brazil using conventional Langmuir probes and High Frequency Capacitance probes are compared with IRI predictions in the light of the spectral distribution of the plasma density irregularities observed. Plasma instability mechani...

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Detalles Bibliográficos
Autores: Muralikrishna, P., Vieira, L. P., Abdu, M. A., de Paula, E. R.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2004
País:México
Institución:UNIVERSIDAD NACIONAL AUTÓNOMA DE MÉXICO
Repositorio:Geofísica Internacional
Idioma:español
inglés
OAI Identifier:oai:revistagi.geofisica.unam.mx:article/861
Acceso en línea:http://revistagi.geofisica.unam.mx/index.php/RGI/article/view/861
Access Level:acceso abierto
Palabra clave:Less Región F
Ionosfera
Densidad electrónica
Prueba de Langmuir
Modelo IRI
Burbujas de plasma
F-region
Ionosphere
Electron density
IRI model
Plasma bubble
Langmuir probe
Descripción
Sumario:In situ electron density profiles obtained from equatorial stations in Brazil using conventional Langmuir probes and High Frequency Capacitance probes are compared with IRI predictions in the light of the spectral distribution of the plasma density irregularities observed. Plasma instability mechanisms, especially Rayleigh-Taylor and Cross-Field instability mechanisms responsible for the generation of observed plasma irregularities, are used to estimate the growth time and the minimum scale size of irregularities at different height regions along the electron density profile. Simple polynomial approximations are used to represent the observed electron density profiles. A comparative study of the observed plasma irregularities with those expected from theory can give information on the reliability of the observed profiles. This reliability estimate is important because the techniques used for the measurement of electron density are known to be associated with some problems. Thus one can see whether the deviations of the observed electron density profiles from IRI predictions are genuine, and what are the physical parameters responsible for the observed deviations in the profiles. Some improvements in the methods used for IRI predictions in low latitudes are suggested.