Nocturnal disturbances of total electron content and their correlation with VHF radio wave scintillations in the Pacific-Asia region

Radio Science ◽  
1993 ◽  
Vol 28 (5) ◽  
pp. 767-773 ◽  
Author(s):  
J. S. Xu ◽  
K. C. Yeh
Keyword(s):  
Radio Wave ◽  
Total Electron Content ◽  
Electron Content ◽  
Total Electron ◽  
The Pacific ◽  
Pacific Asia

scholarly journals Emergence of a localized total electron content enhancement during the severe geomagnetic storm of 8 September 2017

2019 ◽  
Vol 37 (2) ◽  
pp. 153-161 ◽  
Author(s):  
Carlos Sotomayor-Beltran ◽  
Laberiano Andrade-Arenas
Keyword(s):  
Statistical Method ◽  
Total Electron Content ◽  
Geomagnetic Storm ◽  
Orbit Determination ◽  
Geomagnetic Storms ◽  
Electron Content ◽  
Ionospheric Disturbances ◽  
Total Electron ◽  
Equatorial Ionization Anomaly ◽  
The Pacific

Abstract. In this work, the results of the analysis on total electron content (TEC) data before, during and after the geomagnetic storm of 8 September 2017 are reported. One of the responses to geomagnetic storms due to the southern vertical interplanetary magnetic field (Bz) is the enhancement of the electron density in the ionosphere. Vertical TEC (VTEC) from the Center for Orbit determination in Europe (CODE) along with a statistical method were used to identify positive and/or negative ionospheric storms in response to the geomagnetic storm of 8 September 2017. When analyzing the response to the storm of 8 September 2017 it was indeed possible to observe an enhancement of the equatorial ionization anomaly (EIA); however, what was unexpected was the identification of a local TEC enhancement (LTE) to the south of the EIA (∼40∘ S, right over New Zealand and extending towards the southeastern coast of Australia and also eastward towards the Pacific). This was a very transitory LTE that lasted approximately 4 h, starting at ∼ 02:00 UT on 8 September where its maximum VTEC increase was of 241.2 %. Using the same statistical method, comparable LTEs in a similar category geomagnetic storm, the 2015 St. Patrick's Day storm, were looked for. However, for the aforementioned storm no LTEs were identified. As also indicated in a past recent study for a LTE detected during the 15 August 2015 geomagnetic storm, an association between the LTE and the excursion of Bz seen during the 8 September 2017 storm was observed as well. Furthermore, it is very likely that a direct impact of the super-fountain effect along with traveling ionospheric disturbances may be playing an important role in the production of this LTE. Finally, it is indicated that the 8 September 2017 LTE is the second one to be detected since the year 2016.

scholarly journals Global Distribution of Persistence of Total Electron Content Anomaly

Atmosphere ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 297 ◽  
Author(s):  
Yang-Yi Sun ◽  
Jann-Yenq Liu ◽  
Tsung-Yu Wu ◽  
Chieh-Hong Chen
Keyword(s):  
Total Electron Content ◽  
Orbit Determination ◽  
Electron Content ◽  
Neutral Wind ◽  
Eastern Asia ◽  
Total Electron ◽  
The Pacific ◽  
Longitudinal Sector ◽  
Low Latitudes ◽  
The Pacific Ocean

To better understand the ionospheric morphology response to lithospheric activities, we study the global location preference of the positive and negative total electron content (TEC) anomalies persisting continuously for longer than 24 h at middle and low latitudes (within ±60° N geomagnetic latitudes). The TEC is obtained from the global ionospheric map (GIM) of Center for Orbit Determination in Europe (CODE) under the geomagnetic quiet condition of Kp ≤ 3o during the period of 2005 to 2018. There are a few (less than 4%) TEC anomalies that can persist over 24 h. The conjugate phenomenon is most significant in the eastern Asia to Australia longitudinal sector. The result shows the persistence of the positive TEC anomaly along the ring of fire on the western edge of the Pacific Ocean. The high persistence of the TEC anomalies at midlatitudes suggests that thermospheric neutral wind contributes to the anomaly formation.

scholarly journals Emergence of a localized total electron content enhancement during the G4 geomagnetic storm of September 8, 2017

2018 ◽  
Author(s):  
Carlos Sotomayor-Beltran
Keyword(s):  
Statistical Method ◽  
Total Electron Content ◽  
Geomagnetic Storm ◽  
Geomagnetic Storms ◽  
Eastern Coast ◽  
Electron Content ◽  
The South ◽  
Total Electron ◽  
The Pacific ◽  
First Results

Abstract. In this work, the first results of the analysis on total electron content (TEC) data before, during and after the geomagnetic storm of September 8, 2017 are reported. A common response to geomagnetic storms due to the southern vertical interplanetary magnetic field (Bz) is the enhancement of the electron density in the ionosphere. Vertical TEC (VTEC) from the Center for Orbit determination in Europe (CODE) along with a statistical method were used to identify positive and/or negative ionospheric storms in response to the geomagnetic storm of September 8, 2017. When analysing the response to the G4 storm of September 8, 2017 it was indeed possible to observed an enhancement of the equatorial ionization anomaly (EIA); however what it is was unexpected, was the identification of a local TEC enhancement (LTE) to the south of the EIA (~ 40° S), right over New Zealand and extending towards the south-eastern coast of Australia and also eastward towards the Pacific). This was a very transitory LTE that lasted approximately 2 hours, starting at ~ 02:00 UT on September 8 where its maximum VTEC increase was of 241,2 %. Using the same statistical method we looked for LTEs in a similar category geomagnetic storm, the G4 storm of St. Patrick's day of 2015; however for this storm, no LTEs were identified. As also indicated in a past recent study for the August 15, 2015 geomagnetic storm, an association between the LTE and the excursion of Bz observed during the September 8, 2017 storm is observed. Nevertheless, it is more likely that a direct impact of the super-fountain effect along with another ionospheric physical mechanism may be playing an important role in the production of this LTE.

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