Evaluation of E-Layer Dominated Ionosphere Events Using CHAMP, COSMIC/FORMOSAT-3 and FY3C Data

2020 ◽  
Author(s):  
Sumon Kamal ◽  
Norbert Jakowski ◽  
Mohammed M. Hoque ◽  
Jens Wickert
Keyword(s):  
Electron Density ◽  
Space Weather ◽  
Geomagnetic Storms ◽  
Weather Conditions ◽  
Polar Regions ◽  
High Latitudes ◽  
Density Profiles ◽  
Temporal Occurrence ◽  
Electron Density Profiles ◽  
Activity Dependent

<p>Under certain space weather conditions the ionization level of the ionospheric E layer can dominate over that of the F2 layer. This phenomenon is known as “E layer dominated ionosphere” (ELDI) and occurs primarily at high latitudes in the polar regions. The corresponding electron density profiles show their peak ionization at the E layer height between 80 km and 150 km above the Earth’s surface. In this work we have evaluated the influence of space weather and geophysical conditions on the occurrence of ELDI events at high latitudes in the northern and southern hemispheres. For this, we used electron density profiles derived from ionospheric radio occultation measurements aboard CHAMP, COSMIC and FY3C satellites. The used CHAMP data covers the years from 2001 to 2008, the COSMIC data the years from 2006 to 2018 and the FY3C data the years from 2014 to 2018. This provides us continuous data coverage for a long period from 2001 to 2018, containing about 4 million electron density profiles. In addition to the geospatial distribution, we have also investigated the temporal occurrence of ELDI events in the form of the diurnal, the seasonal and the solar activity dependent variation. We have further investigated the influence of geomagnetic storms on the spatial and temporal occurrence of ELDI events.</p>

NeQuick2 and IRI2012 models applied to mid and high latitudes, and the Antarctic ionosphere

2017 ◽  
Vol 29 (3) ◽  
pp. 265-276 ◽  
Author(s):  
M. Pietrella ◽  
B. Nava ◽  
M. Pezzopane ◽  
Y. Migoya Orue ◽  
A. Ippolito ◽  
...  
Keyword(s):  
Electron Density ◽  
Activity Index ◽  
High Latitudes ◽  
Limited Sample ◽  
Density Profiles ◽  
Solar Activity Index ◽  
Macquarie Island ◽  
Electron Density Profiles ◽  
The Antarctic ◽  
Better Than

AbstractWithin the framework of the AUSPICIO (AUtomatic Scaling of Polar Ionograms and Co-operative Ionospheric Observations) project, a limited sample of ionograms recorded mostly in 2001 and 2009, and to a lesser extent in 2006–07 and 2012–15, at the ionospheric observatories of Hobart and Macquarie Island (mid-latitude), Comandante Ferraz and Livingstone Island (high latitude), and Casey, Mawson, Davis and Scott Base (inside the Antarctic Polar Circle (APC)) were considered to study the capability of the NeQuick2 and IRI2012 models for predicting the behaviour of the ionosphere at mid- and high latitudes and over the Antarctic area. The applicability of NeQuick2 and IRI2012 was evaluated as i) climatological models taking as input the F10.7 solar activity index and ii) assimilative models ingesting the foF2 and hmF2 measurements obtained from the electron density profiles provided by the Adaptive Ionospheric Profiler (AIP). The statistical analysis results reveal that the best description of the ionosphere’s electron density is achieved when the AIP measurements are ingested into the NeQuick2 and IRI2012 models. Moreover, NeQuick2 performance is far better than IRI2012 performance outside the APC. Conversely, the IRI2012 model performs better than the NeQuick2 model inside the APC.

scholarly journals Temporal and spatial variations in ionospheric electron density profiles over South Africa during strong magnetic storms

2013 ◽  
Vol 13 (2) ◽  
pp. 375-384 ◽  
Author(s):  
Y. B. Yao ◽  
P. Chen ◽  
S. Zhang ◽  
J. J. Chen
Keyword(s):  
South Africa ◽  
Electron Density ◽  
Geomagnetic Storms ◽  
Magnetic Storms ◽  
Electron Content ◽  
Vertical Total Electron Content ◽  
Ionospheric Electron Density ◽  
Density Profiles ◽  
Total Electron ◽  
Electron Density Profiles

Abstract. Observations from the South African TrigNet global navigation satellite system (GNSS) and vertical total electron content (VTEC) data from the Jason-1 satellite were used to analyze the variations in ionospheric electron density profiles over South Africa before and after the severe geomagnetic storms on 15 May 2005. Computerized ionospheric tomography (CIT) was used to inverse the 3-D structure of ionospheric electron density and its response to the magnetic storms. Inversion results showed that electron density significantly increased at 10:00 UT, 15 May compared with that at the same period on 14 May. Positive ionospheric storms were observed in the inversion region during the magnetic storms. Jason-1 data show that the VTEC observed on descending orbits on 15 May significantly increased, whereas that on ascending orbits only minimally changed. This finding is identical to the CIT result.

Electron density profiles above the F-layer

1973 ◽  
Vol 21 (9) ◽  
pp. 1581-1586
Author(s):  
Michael Anastassiadis ◽  
Georges Moraitis ◽  
Dimitris Matsoukas
Keyword(s):  
Electron Density ◽  
Density Profiles ◽  
Electron Density Profiles

scholarly journals Ionospheric assimilation techniques for ARGOS Low-Resolution Airglow and Aurora Spectrograph (LORAAS) tomographically reconstructed equatorial electron density profiles

Radio Science ◽  
2004 ◽  
Vol 39 (1) ◽  
pp. n/a-n/a ◽  
Author(s):  
J. J. Sojka ◽  
J. V. Eccles ◽  
R. W. Schunk ◽  
S. McDonald ◽  
S. Thonnard ◽  
...  
Keyword(s):  
Electron Density ◽  
Low Resolution ◽  
Density Profiles ◽  
Electron Density Profiles

scholarly journals Variations of topside ionospheric scale heights over Millstone Hill during the 30-day incoherent scatter radar experiment

2007 ◽  
Vol 25 (9) ◽  
pp. 2019-2027 ◽  
Author(s):  
L. Liu ◽  
W. Wan ◽  
M.-L. Zhang ◽  
B. Ning ◽  
S.-R. Zhang ◽  
...  
Keyword(s):  
Electron Density ◽  
Thermal Structure ◽  
Plasma Temperature ◽  
Scale Height ◽  
Incoherent Scatter Radar ◽  
Density Profiles ◽  
Incoherent Scatter ◽  
Scatter Radar ◽  
Vertical Scale ◽  
Electron Density Profiles

Abstract. A 30-day incoherent scatter radar (ISR) experiment was conducted at Millstone Hill (288.5° E, 42.6° N) from 4 October to 4 November 2002. The altitude profiles of electron density Ne, ion and electron temperature (Ti and Te), and line-of-sight velocity during this experiment were processed to deduce the topside plasma scale height Hp, vertical scale height VSH, Chapman scale height Hm, ion velocity, and the relative altitude gradient of plasma temperature (dTp/dh)/Tp, as well as the F2 layer electron density (NmF2) and height (hmF2). These data are analyzed to explore the variations of the ionosphere over Millstone Hill under geomagnetically quiet and disturbed conditions. Results show that ionospheric parameters generally follow their median behavior under geomagnetically quiet conditions, while the main feature of the scale heights, as well as other parameters, deviated significantly from their median behaviors under disturbed conditions. The enhanced variability of ionospheric scale heights during the storm-times suggests that the geomagnetic activity has a major impact on the behavior of ionospheric scale heights, as well as the shape of the topside electron density profiles. Over Millstone Hill, the diurnal behaviors of the median VSH and Hm are very similar to each other and are not so tightly correlated with that of the plasma scale height Hp or the plasma temperature. The present study confirms the sensitivity of the ionospheric scale heights over Millstone Hill to thermal structure and dynamics. The values of VSH/Hp tend to decrease as (dTp/dh)/Tp becomes larger or the dynamic processes become enhanced.

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