Ion outflows and artificial ducts in the topside ionosphere at HAARP

2010 ◽  
Vol 37 (18) ◽  
pp. n/a-n/a ◽  
Author(s):  
G. M. Milikh ◽  
E. Mishin ◽  
I. Galkin ◽  
A. Vartanyan ◽  
C. Roth ◽  
...  
Keyword(s):  
Topside Ionosphere

scholarly journals Looking for a proxy of the ionospheric turbulence with Swarm data

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Paola De Michelis ◽  
Giuseppe Consolini ◽  
Alessio Pignalberi ◽  
Roberta Tozzi ◽  
Igino Coco ◽  
...  
Keyword(s):  
Electron Density ◽  
Geomagnetic Activity ◽  
Density Fluctuations ◽  
Rate Of Change ◽  
Topside Ionosphere ◽  
Joint Probability Distribution ◽  
Activity Levels ◽  
Scaling Exponents ◽  
Electron Density Fluctuations ◽  
Scaling Features

AbstractThe present work focuses on the analysis of the scaling features of electron density fluctuations in the mid- and high-latitude topside ionosphere under different conditions of geomagnetic activity. The aim is to understand whether it is possible to identify a proxy that may provide information on the properties of electron density fluctuations and on the possible physical mechanisms at their origin, as for instance, turbulence phenomena. So, we selected about 4 years (April 2014–February 2018) of 1 Hz electron density measurements recorded on-board ESA Swarm A satellite. Using the Auroral Electrojet (AE) index, we identified two different geomagnetic conditions: quiet (AE < 50 nT) and active (AE > 300 nT). For both datasets, we evaluated the first- and second-order scaling exponents and an intermittency coefficient associated with the electron density fluctuations. Then, the joint probability distribution between each of these quantities and the rate of change of electron density index was also evaluated. We identified two families of plasma density fluctuations characterized by different mean values of both the scaling exponents and the considered ionospheric index, suggesting that different mechanisms (instabilities/turbulent processes) can be responsible for the observed scaling features. Furthermore, a clear different localization of the two families in the magnetic latitude—magnetic local time plane is found and its dependence on geomagnetic activity levels is analyzed. These results may well have a bearing about the capability of recognizing the turbulent character of irregularities using a typical ionospheric plasma irregularity index as a proxy.

Anomalous features of the electron density in the topside ionosphere

1969 ◽  
Vol 311 (1507) ◽  
pp. 501-516 ◽  
Keyword(s):  
Electron Density ◽  
Power Supply ◽  
Data Rate ◽  
Power Lines ◽  
Topside Ionosphere ◽  
Telemetry Data ◽  
Electron Density And Temperature

The instruments which measure electron density and temperature are quite separate and independent in operation, but on account of the limitations in power supply and telemetry data rate the two experiments share the same power lines and some data channels.

scholarly journals Deriving the effective scale height in the topside ionosphere based on ionosonde and satellite in situ observations

2014 ◽  
Vol 119 (10) ◽  
pp. 8472-8482 ◽  
Author(s):  
Libo Liu ◽  
He Huang ◽  
Yiding Chen ◽  
Huijun Le ◽  
Baiqi Ning ◽  
...  
Keyword(s):  
Scale Height ◽  
Topside Ionosphere ◽  
In Situ Observations

scholarly journals Topside Ionosphere and Plasmasphere Modelling Using GNSS Radio Occultation and POD Data

2021 ◽  
Vol 13 (8) ◽  
pp. 1559
Author(s):  
Fabricio S. Prol ◽  
M. Mainul Hoque
Keyword(s):  
Solar Activity ◽  
Electron Density ◽  
Radio Occultation ◽  
Geomagnetic Latitude ◽  
Low Earth Orbit ◽  
Activity Level ◽  
Topside Ionosphere ◽  
Electron Content ◽  
Total Electron ◽  
Solar Activity Level

A 3D-model approach has been developed to describe the electron density of the topside ionosphere and plasmasphere based on Global Navigation Satellite System (GNSS) measurements onboard low Earth orbit satellites. Electron density profiles derived from ionospheric Radio Occultation (RO) data are extrapolated to the upper ionosphere and plasmasphere based on a linear Vary-Chap function and Total Electron Content (TEC) measurements. A final update is then obtained by applying tomographic algorithms to the slant TEC measurements. Since the background specification is created with RO data, the proposed approach does not require using any external ionospheric/plasmaspheric model to adapt to the most recent data distributions. We assessed the model accuracy in 2013 and 2018 using independent TEC data, in situ electron density measurements, and ionosondes. A systematic better specification was obtained in comparison to NeQuick, with improvements around 15% in terms of electron density at 800 km, 26% at the top-most region (above 10,000 km) and 26% to 55% in terms of TEC, depending on the solar activity level. Our investigation shows that the developed model follows a known variation of electron density with respect to geographic/geomagnetic latitude, altitude, solar activity level, season, and local time, revealing the approach as a practical and useful tool for describing topside ionosphere and plasmasphere using satellite-based GNSS data.

scholarly journals WN4 effect on longitudinal distribution of different ion species in the topside ionosphere at low latitudes by means of DEMETER, DMSP-F13 and DMSP-F15 data

2009 ◽  
Vol 27 (7) ◽  
pp. 2893-2902 ◽  
Author(s):  
L. Bankov ◽  
R. Heelis ◽  
M. Parrot ◽  
J.-J. Berthelier ◽  
P. Marinov ◽  
...  
Keyword(s):  
Density Distribution ◽  
Major Ions ◽  
Local Times ◽  
Longitudinal Distribution ◽  
Topside Ionosphere ◽  
Regular Feature ◽  
Ion Density ◽  
F Region ◽  
Longitudinal Variations ◽  
Ion Species

Abstract. Plasma probe data from DMSP-F13, DMSP-F15 and DEMETER satellites were used to examine longitudinal structures in the topside equatorial ionosphere during fall equinox conditions of 2004 year. Since the launch of DEMETER satellite on 29 June 2004, all these satellites operate close together in the topside ionosphere. Here, data taken from Special Sensor-Ion, Electron and Scintillations (SSIES) instruments on board DMSP-F13, F15 and Instrument Analyser de Plasma (IAP) on DEMETER, are used. Longitudinal variations in the major ions at two altitudes (~730 km for DEMETER and ~840 km for DMSP) are studied to further describe the recently observed "wavenumber-four" (WN4) structures in the equatorial topside ionosphere. Different ion species H+, He+ and O+ have a rather complex longitudinal behavior. It is shown that WN4 is almost a regular feature in O+ the density distribution over all local times covered by these satellites. In the evening local time sector, H+ ions follow the O+ behavior within WN4 structures up to the pre-midnight hours. Near sunrise H+ and later in the daytime, He+ longitudinal variations are out of phase with respect to O+ ions and effectively reduce the effect of WN4 on total ion density distribution at altitudes 730–840 km. It is shown that both a WN4 E×B drift driver and local F-region winds must be considered to explain the observed ion composition variations.

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