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Found 14 entries in the Bibliography.
Showing entries from 1 through 14
| 2022 |
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Using a suite of instruments, which included a chain of ground-based dual-frequency GPS receivers, and magnetometers, we have studied the importance of thermospheric meridional wind circulation in controlling the distribution of plasma over the Indian low latitude ionospheric regions during the period of a severe geomagnetic storm. The storm on 15 May 2005, which had its onset coinciding with the local noon time sector for the Indian ionospheric zone, was a severe geomagnetic storm with symH ∼ - 305 nT. A steep increase i ... Published by: Advances in Space Research Published on: oct YEAR: 2022 DOI: 10.1016/j.asr.2022.06.027 Compositional disturbances; Equatorial ionosphere; geomagnetic storm; total electron content |
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This study investigates the sequence of solar and interplanetary events that drove the 1 June 2013 and October 2015 geomagnetic storms and how the American (68°–78oE) and African (32°–42oE) Equatorial Ionization Anomaly (EIA) regions responded to them. We constructed the EIA structures by using Total Electron Content (TEC) and ionospheric irregularities derived from Global Navigation Satellite System (GNSS) receivers along with the study locations. We also analyzed disturbed time ionospheric electric field and model da ... Oyedokun, Oluwole; Amaechi, P.; Akala, A.; Simi, K.; Ogwala, Aghogho; Oyeyemi, E.; Published by: Advances in Space Research Published on: mar YEAR: 2022 DOI: 10.1016/j.asr.2021.12.027 geomagnetic storm; total electron content; Corotating Interacting Region; ionospheric irregularities |
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We present the results of study on the variations of ionospheric total electron content (TEC) by using global, hemispheric, and regional electron contents computed from the global ionospheric maps (GIMs) for the period from 1999 to 2020. For a low and moderate solar activity, the global and regional electron contents vary linearly with solar 10.7 cm radio flux and EUV flux. While a saturation effect in the electron content verses EUV and F10.7 is found during the high solar activity periods at all regions, the maximum effec ... Younas, Waqar; Amory-Mazaudier, C.; Khan, Majid; Amaechi, Paul; Published by: Advances in Space Research Published on: jul YEAR: 2022 DOI: 10.1016/j.asr.2022.07.029 annual variation; global electron content; Ionosphere; semi-annual variation; total electron content |
| 2021 |
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This work analyzes the geo-effectiveness of Coronal Mass Ejection- (CME-) induced storms by investigating the responses of ionospheric Vertical Total Electron Content (VTEC) and the Equatorial Ionization Anomaly (EIA) over the Indian sector to two storms. One of the storms occurred on February 19, 2014 (SYM-H: −120 nT), while the other occurred on June 23, 2015 (SYM-H: −204 nT). Both storms were driven by full halo CMEs. Global TEC maps were used to characterize VTEC variations during the storms. June 23, 2015 storm was ... Simi, K.; Akala, A.; Krishna, Siva; Amaechi, Paul; Ogwala, Aghogho; Ratnam, Venkata; Oyedokun, O.; Published by: Advances in Space Research Published on: oct YEAR: 2021 DOI: 10.1016/j.asr.2021.06.013 Coronal mass ejection; Disturbance dynamo electric field; geomagnetic storm; prompt penetration electric field; total electron content |
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Assessment of the predictive capabilities of NIGTEC model over Nigeria during geomagnetic storms The Nigerian Total Electron Content (NIGTEC) is a regional neural network-based model developed by the Nigerian Centre for Atmospheric Research to predict the Total Electron Content (TEC) at any location over Nigeria. The addition of the disturbance storm time (Dst) index as one of NIGTEC s input layer neurons raises a question of its accuracy during geomagnetic storms. In this paper, the capability of NIGTEC in predicting the variability of TEC during geomagnetic storms has been assessed. TEC data predicted by NIGTEC is com ... Amaechi, Paul; Humphrey, Ibifubara; Adewoyin, David; Published by: Geodesy and Geodynamics Published on: nov YEAR: 2021 DOI: 10.1016/j.geog.2021.09.003 geomagnetic storm; global navigation satellite system; Nigerian Total Electron Content (NIGTEC); total electron content |
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Effects of the 12 May 2021 Geomagnetic Storm on Georeferencing Precision In this work, we present the positioning error analysis of the 12 May 2021 moderate geomagnetic storm. The storm happened during spring in the northern hemisphere (fall in the south). We selected 868 GNSS stations around the globe to study the ionospheric and the apparent position variations. We compared the day of the storm with the three previous days. The analysis shows the global impact of the storm. In the quiet days, 93\% of the stations had 3D errors less than 10 cm, while during the storm, only 41\% kept this level o ... Valdés-Abreu, Juan; Díaz, Marcos; Báez, Juan; Stable-Sánchez, Yohadne; Published by: Remote Sensing Published on: jan YEAR: 2021 DOI: 10.3390/rs14010038 Geomagnetic storms; total electron content; global navigation satellite system; Global positioning system; precise point positioning; rate of change of the tec index |
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B2 Thickness Parameter Response to Equinoctial Geomagnetic Storms The thickness parameters that most empirical models use are generally defined by empirical relations related to ionogram characteristics. This is the case with the NeQuick model that uses an inflection point below the F2 layer peak to define a thickness parameter of the F2 bottomside of the electron density profile, which is named B2. This study is focused on the effects of geomagnetic storms on the thickness parameter B2. We selected three equinoctial storms, namely 17 March 2013, 2 October 2013 and 17 March 2015. To invest ... Migoya-Orué, Yenca; Alazo-Cuartas, Katy; Kashcheyev, Anton; Amory-Mazaudier, Christine; Radicella, Sandro; Nava, Bruno; Fleury, Rolland; Ezquer, Rodolfo; Published by: Sensors Published on: jan YEAR: 2021 DOI: 10.3390/s21217369 Geomagnetic storms; total electron content; ionospheric empirical models; NeQuick model; thickness parameter |
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Improved model of ionosphere variability and study for long-term statistical characteristics Ionospheric variability is influenced by many factors, such as solar radiation, neutral atmosphere composition, and geomagnetic disturbances. Mainly characterized by the total electron content (TEC) and electron density, the climatology of the ionosphere features temporal and spatial changes. Establishing a multivariant regression model helps substantially in better understanding the ionosphere characteristics and their long-term variability. In this paper, an improvement of the existing ionosphere multivariate linear fittin ... Published by: Chinese Journal of Aeronautics Published on: feb YEAR: 2021 DOI: 10.1016/j.cja.2020.03.018 total electron content; Analysis of anomalies; Long-term statistics; Regression model |
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The delayed ionospheric response is analyzed for two well-defined 27-day solar rotation periods in the year 2019 with solar radio flux index F10.7 and Global-scale Observations of the Limb and Disk (GOLD) data, like solar extreme ultraviolet (EUV) flux proxy, O/N2 column density ratio and peak electron density, as well as International Global Navigation Satellite System Service rapid high-rate total electron content (TEC) map data. Although the correlation between GOLD solar EUV flux proxy and TEC is similar to the correlati ... Schmölter, Erik; Berdermann, Jens; Codrescu, Mihail; Published by: Journal of Geophysical Research: Space Physics Published on: YEAR: 2021 DOI: 10.1029/2020JA028861 Ionosphere; solar proxies; time delay; total electron content |
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Equatorial Ionospheric Electrodynamics The low-latitude ionosphere is one of the most dynamic regions of the Earth s upper atmosphere. The morphology of this region is controlled by radiative and coupled chemical, neutral, and plasma transport processes. Equatorial electrodynamics plays a fundamental role on the low-latitude plasma density, total electron content (TEC), and plasma structures and waves extending from the E-region to the protonosphere. Ground-based and satellite measurements over the last six decades determined the climatology of quiet- and storm-t ... Published by: Published on: YEAR: 2021 DOI: 10.1002/9781119815617.ch9 total electron content; equatorial ionospheric electrodynamics; low-latitude plasma density; quiet-time equatorial plasma drifts; storm-time equatorial electric fields |
| 2015 |
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We studied the contribution of the global plasmaspheric and ionospheric electron content (PEC and IEC) into total electron content (TEC). The experimental PEC was estimated by comparison of GPS TECobservations and FORMOSAT-3/COSMIC radio occultation IEC measurements. Results are retrieved for the winter solstice (January and December 2009) conditions. Global maps of COSMIC-derived IEC, PECand GPS TEC were compared with Global Self-consistent ... Klimenko, M.V.; Klimenko, V.V.; Zakharenkova, I.E.; Cherniak, Iu.V.; Published by: Advances in Space Research Published on: 06/2014 YEAR: 2015 DOI: 10.1016/j.asr.2014.06.027 FORMOSAT-3/COSMIC; GPS; Numerical modeling; Plasmasphere; total electron content |
| 2013 |
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Ionospheric symmetry caused by geomagnetic declination over North America We describe variations in total electron content (TEC) in the North American sector exhibiting pronounced longitudinal progression and symmetry with respect to zero magnetic declination. Patterns were uncovered by applying an empirical orthogonal function (EOF) decomposition procedure to a 12 year ground-based American longitude sector GPS TEC data set. The first EOF mode describes overall average TEC, while the strong influence of geomagnetic declination on the midlatitude ionosphere is found in the second EOF mode (or t ... Zhang, Shun-Rong; Chen, Ziwei; Coster, Anthea; Erickson, Philip; Foster, John; Published by: Geophysical Research Letters Published on: 10/2014 YEAR: 2013 DOI: 10.1002/grl.v40.2010.1002/2013GL057933 geomagnetic field; midlatitude ionosphere; thermospheric winds; total electron content |
| 2009 |
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This paper presents an investigation of geomagnetic storm effects in the equatorial and middle-low latitude F-region in the West Pacific sector during the intense geomagnetic storm on 13\textendash17 April, 2006. The event, preceded by a minor storm, started at 2130 UT on April 13 while interplanetary magnetic field (IMF)\ Bzcomponent was ready to turn southward. From 14\textendash17 the ionosphere was characterized by a large scale enhancement in critical frequency, foF2 (4\~6\ MHz) and tota ... Zhao, Biqiang; Wan, Weixing; Liu, Libo; Igarashi, K.; Yumoto, K.; Ning, Baiqi; Published by: Journal of Atmospheric and Solar-Terrestrial Physics Published on: Jan-01-2009 YEAR: 2009 DOI: 10.1016/j.jastp.2008.09.029 |
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Ionospheric response to the geomagnetic storm on 13–17 April 2006 in the West Pacific region This paper presents an investigation of geomagnetic storm effects in the equatorial and middle-low latitude F-region in the West Pacific sector during the intense geomagnetic storm on 13–17 April, 2006. The event, preceded by a minor storm, started at 2130 UT on April 13 while interplanetary magnetic field (IMF) Bz component was ready to turn southward. From 14–17 the ionosphere was characterized by a large scale enhancement in critical frequency, foF2 (4∼6MHz) and total electron content (TEC) (∼30TECU, 1TECU=1×1016 ... Zhao, Biqiang; Wan, Weixing; Liu, Libo; Igarashi, K.; Yumoto, K.; Ning, Baiqi; Published by: Journal of Atmospheric and Solar-Terrestrial Physics Published on: YEAR: 2009 DOI: https://doi.org/10.1016/j.jastp.2008.09.029 |
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