scholarly journals Ionospheric precursors to scintillation activity

2014 ◽  
Vol 57 (1) ◽  
Author(s):  
Paul S.J. Spencer
Keyword(s):  
Electron Density ◽  
Ionospheric Scintillation ◽  
Small Scale ◽  
Navigation Systems ◽  
Radio Waves ◽  
Ionospheric Electron Density ◽  
Plasma Drift ◽  
L Band ◽  
Electron Density Irregularities ◽  
Tomographic Inversions

<p>Ionospheric scintillation is the rapid fluctuation of both phase and amplitude of trans-ionospheric radio waves due to small scale electron density irregularities in the ionosphere. Prediction of the occurrence of scintillation at L band frequencies is needed to mitigate the disruption of space-based communication and navigation systems. The purpose of this paper is to present a method of using tomographic inversions of the ionospheric electron density obtained from ground-based GPS data to infer the location and strength of the post-sunset plasma drift vortex. This vortex is related to the pre-reversal enhancement in the eastwards electric field which has been correlated to the subsequent occurrence of scintillation.</p>

scholarly journals Numerical simulation of oblique ionospheric heating by powerful radio waves

2018 ◽  
Vol 36 (3) ◽  
pp. 855-866
Author(s):  
Moran Liu ◽  
Chen Zhou ◽  
Xiang Wang ◽  
Bin Bin Ni ◽  
Zhengyu Zhao
Keyword(s):  
Ray Tracing ◽  
Electron Density ◽  
Oblique Incidence ◽  
Three Dimensional ◽  
Radio Waves ◽  
Powerful Radio ◽  
Ionospheric Electron Density ◽  
Ionospheric Heating ◽  
Tracing Algorithm ◽  
Electron Density And Temperature

<p><strong>Abstract.</strong> In this paper, we investigate the ionospheric heating by oblique incidence of powerful high-frequency (HF) radio waves using three-dimensional numerical simulations. The ionospheric electron density and temperature perturbations are examined by incorporating the ionospheric electron transport equations and ray-tracing algorithm. The energy distribution of oblique incidence heating waves in the ionosphere is calculated by the three-dimensional ray-tracing algorithm. The calculation takes into consideration the electric field of heating waves in the caustic region by the plane wave spectral integral method. The simulation results show that the ionospheric electron density and temperature can be disturbed by oblique incidence of powerful radio waves, especially in the caustic region of heating waves. The oblique ionospheric heating with wave incidence parallel and perpendicular to the geomagnetic field in the mid-latitude ionosphere is explored by simulations, results of which indicate that the ionospheric modulation is more effective when the heating wave propagates along the magnetic field line. Ionospheric density and temperature striations in the caustic region due to thermal self-focusing instability are demonstrated, as well as the time evolution of the corresponding fluctuation spectra.</p>

scholarly journals Spatial structure of auroral day-time ionospheric electron density irregularities generated by a powerful HF-wave

1998 ◽  
Vol 16 (7) ◽  
pp. 812-820 ◽  
Author(s):  
E. D. Tereshchenko ◽  
B. Z. Khudukon ◽  
M. T. Rietveld ◽  
A. Brekke
Keyword(s):  
Statistical Analysis ◽  
Radio Wave ◽  
Electron Density ◽  
Large Scale ◽  
Density Fluctuations ◽  
Small Scale ◽  
Ionospheric Heating ◽  
Mean Values ◽  
Hf Wave ◽  
Electron Density Irregularities

Abstract. We describe an experiment in satellite radio-wave probing of the ionosphere, modified by powerful waves from the HF heating facility at Tromsø (Norway) in May 1995. Amplitude scintillations and variations of the phase of VHF signals from Russian navigational satellites passing over the heated region were observed. We show that both large-scale electron density irregularities (several tens of kilometers in size) and small-scale ones (from hundreds of meters to kilometers) can be generated by the HF radiation. Maximum effects caused by small-scale irregularities detected in the satellite signals are observed in the directions sector approximately parallel to the geomagnetic field lines although large-scale structures can be detected within a much larger area. The properties of small-scale irregularities (electron density fluctuations) are investigated by applying a statistical analysis and by studying experimental and model mean values of the logarithm of the relative amplitude of the signal. The results indicate that satellite radio probing can be a supporting diagnostic technique for ionospheric heating and add valuable information to studies of effects produced by HF modification.Key words. Satellite radio-wave probing · HF radiation · Electron density irregularities · Statistical analysis · Ionospheric heating

scholarly journals Experimental observations of medium and small scale electrostatic waves associated with ionospheric electron density fluctuations

2004 ◽  
Vol 43 (2) ◽  
pp. 173-186
Author(s):  
P. Muralikrishna ◽  
L. P. Vieira ◽  
M. A. Abdu
Keyword(s):  
Electron Density ◽  
Density Fluctuations ◽  
Small Scale ◽  
Ionospheric Electron Density ◽  
Electrostatic Waves ◽  
Electron Density Fluctuations

El 18 de diciembre, 1995 a las 21:17 hrs (TL) se colocaron a bordo de la SONDA III brasileña una prueba de Langmuir yuna de Capacitancia de Alta Frecuencia. Esta sonda fue lanzada desde la estación de lanzamiento de Alcantara (2.31°S; 44.4°W) en Brasil, para realizar mediciones de las variaciones con la altura del campo eléctrico ionosférico y de la densidad electrónica. La nave alcanzó una altitud de 557 km y cubrió un rango horizontal de 589 km. Se operaron desde tierra varios equipos para monitorear las condiciones ionosféricas durante el lanzamiento de modo que la nave alcanzara la región F, donde se presentan las burbujas de plasma. La nave alcanzó la altitud de 557 km y atravesó varias burbujas de plasma de mediano tamaño principalmente en donde se encuentra un perfil downleg de densidad. La densidad electrónica en la parte upleg del perfil mostró la presencia de una muy definida base de la región F alrededor de los 300 km, mientras que el downleg mostró la presencia de un amplio espectro de campo eléctrico e irregularidades en la densidad electrónica y el upleg de la capa F. El análisis espectral de las fluctuaciones en la densidad electrónica y el campo eléctrico indican la presencia de picos espectrales muy definidos a varias alturas que en la mayoría de los casos están asociados unos con otros. Probablemente esto indica la naturaleza electrostática de las ondas eléctricas que se excitan probablemente al inicio de la inestabilidad del plasma junto con las ondas de densidad. Se presentan algunos nuevos resultados de la asociación de estas fluctuaciones con las burbujas de plasma.

Sign in / Sign up

Export Citation Format

Share Document