14:30 〜 14:45
[PEM12-10] Electrodynamic, ionospheric and thermospheric effects during the 10-11 May 2024 geomagnetic superstorm
★Invited Papers
キーワード：Ionosphere, Thermosphere, geomagnetic storm
On 10 May 2024, powerful coronal mass ejections (CME) arrived at Earth and caused a major geomagnetic storm. With the minimum SYM-H excursion of -518 nT, this storm is the strongest geomagnetic disturbance that occurred on Earth since March 1989.
In this work, we use a set of ground-based (GNSS-receivers, magnetometers) and space-borne (Swarm, DMSP, GOLD) instruments to analyse the electrodynamic, ionospheric and thermospheric response to this superstorm event.
With the CME arrival at 17:05UT, the dayside low-latitude magnetic field measurements (dH) showed a major sudden increase of +150 +220 nT, indicating extreme storm-time alterations of the equatorial electric fields due to the prompt penetration electric fields (PPEF). Following this major impact, we observed the development of a significant super-fountain effect and the uplift of the ionospheric plasma throughout the whole dayside, from the pre-noon to the evening local hours. During the maximum disturbance at ~23:30UT on 10 May, the distance between the equatorial ionization anomaly (EIA) crests reached unprecedented 60 degrees of latitude, and the GNSS total electron content (TEC) within the EIA crests increased to 170 TECU, which is ~15 times higher than the undisturbed values. Concurrently, data from Swarm A data (19LT) showed an extreme increase of the up-looking vertical electron content up to 130 TECU above ~470 km of altitude, which represents ~75% of the TEC between 0 and 20200 km. Moreover, the DMSP satellite measurements in the evening sector showed the presence of a 2-peak EIA and a dramatic 500-600% increase of the total ion density above ~850 km, which are extremely rare observations.
We note that, while the observed dayside ionospheric effects are quite significant, they are less intense than those that occurred during the 15 July 2000 and 29-30 October 2003 superstorms. During the recovery phase, a severe negative storm was observed in the American sector, associated with vortex-like changes in the thermospheric composition O/N2 ratio. The negative deviation occurred during the recovery phase of the May 2024 storm is one of the strongest ever observed since the beginning of the GPS/GNSS VTEC era.
In this work, we use a set of ground-based (GNSS-receivers, magnetometers) and space-borne (Swarm, DMSP, GOLD) instruments to analyse the electrodynamic, ionospheric and thermospheric response to this superstorm event.
With the CME arrival at 17:05UT, the dayside low-latitude magnetic field measurements (dH) showed a major sudden increase of +150 +220 nT, indicating extreme storm-time alterations of the equatorial electric fields due to the prompt penetration electric fields (PPEF). Following this major impact, we observed the development of a significant super-fountain effect and the uplift of the ionospheric plasma throughout the whole dayside, from the pre-noon to the evening local hours. During the maximum disturbance at ~23:30UT on 10 May, the distance between the equatorial ionization anomaly (EIA) crests reached unprecedented 60 degrees of latitude, and the GNSS total electron content (TEC) within the EIA crests increased to 170 TECU, which is ~15 times higher than the undisturbed values. Concurrently, data from Swarm A data (19LT) showed an extreme increase of the up-looking vertical electron content up to 130 TECU above ~470 km of altitude, which represents ~75% of the TEC between 0 and 20200 km. Moreover, the DMSP satellite measurements in the evening sector showed the presence of a 2-peak EIA and a dramatic 500-600% increase of the total ion density above ~850 km, which are extremely rare observations.
We note that, while the observed dayside ionospheric effects are quite significant, they are less intense than those that occurred during the 15 July 2000 and 29-30 October 2003 superstorms. During the recovery phase, a severe negative storm was observed in the American sector, associated with vortex-like changes in the thermospheric composition O/N2 ratio. The negative deviation occurred during the recovery phase of the May 2024 storm is one of the strongest ever observed since the beginning of the GPS/GNSS VTEC era.