| Autor: |
Fashae, J. B.1 (AUTHOR) Joshua.fashae@bowen.edu.ng, Bolaji, O. S.1,2 (AUTHOR), Rabiu, A. B.1,3 (AUTHOR), Ajani, O. O.1 (AUTHOR), Fadiji, J. O.1 (AUTHOR) |
| Předmět: |
|
| Zdroj: |
Journal of Geophysical Research. Space Physics. Oct2023, Vol. 128 Issue 10, p1-16. 16p. |
| Abstrakt: |
This study investigates the response of the Asian‐Australian low‐latitude ionosphere to the 2013 Sudden Stratospheric Warming (SSW) event. The equatorial ionization anomaly structures were built from the latitudinal distribution of Total Electron Content (TEC) measured from 10 Global Positioning System receivers along 115°E in the Asian‐Australian sector. A pair of magnetometers and NASA Thermosphere‐Ionosphere‐Mesosphere Energetics and Dynamics satellite airglow instrument were also employed to measure the equatorial electrojet strength (inferred E × B drift) and to unveil the changes in the neutral thermospheric O/N2 ratio during the SSW event, respectively. The relocation of the northern crests to higher latitudes during the SSW compared to the non‐SSW periods was mainly attributed to the combined effect of enhanced magnetometer‐inferred upward‐directed E × B drift and increasing solar flux. The local time shift in the thermospheric O/N2 ratio, a slight enhancement in the magnitude of the semi‐diurnal magnetometer‐inferred upward‐directed E × B drift, and changes in solar flux were primarily responsible for the hemispheric TEC enhancement during mid‐January compared to SSW onset. Additionally, the photo‐ionization effect due to increasing solar flux further enhances the TEC magnitude during the relaxing phase. On the other hand, the strong thermospheric equatorward wind played a crucial role in moving the plasma to lower latitudes during the zonal wind transition phases. A moderate geomagnetic storm of 17 January 2013 did not perturb the Asian‐Australian ionosphere. However, on 18 January 2013, the storm had a significant impact and greatly diminished the effect of the SSW. Plain Language Summary: The ionospheric response of the 2013 Sudden Stratospheric Warming (SSW) event over the Asian‐Australian sector was investigated using the data from Global Positioning System receivers to plot the daily equatorial ionization anomaly signature. We employed a pair of magnetometers and the NASA Thermosphere‐Ionosphere‐Mesosphere Energetics and Dynamics satellite airglow instrument revealing the varying vertical inferred E × B drift and global changes in the neutral composition O/N2 ratio respectively. The northern poleward movement of plasma was observed during the SSW periods compared to the non‐SSW period. This poleward movement is significantly due to the combined physical processes such as enhanced inferred upward‐directed E × B drift and increasing solar flux. The enhancement in Total Electron Content magnitude during the relaxing period was mainly due to the increasing solar flux. A moderate geomagnetic storm of 17 January 2013 did not play any significant role in the Asian‐Australian ionosphere due to differences in local time. Key Points: The coupling between the lower and upper atmosphere is most visible during the Sudden Stratospheric Warming (SSW) eventThe relocation of the northern crests to higher latitudes was primarily attributed to inferred E × B drift and thermospheric poleward windIncreasing solar flux was responsible for the enhancement in hemispheric Total Electron Content magnitude during the SSW relaxing phase [ABSTRACT FROM AUTHOR] |
| Databáze: |
GreenFILE |
| Externí odkaz: |
|
Plný text