DATE2026.06.18 #Press Releases
Giant Magnetic Storm Transports Large Amounts of Oxygen Ions from Earth's Atmosphere to Space
Disclaimer: machine translated by DeepL which may contain errors.
Discovery of Extreme Conditions and New Supply Mechanism for O+ Over 90% in the Near-Earth Region
Summary
A research group led by Project Associate Professor Yuki Ohana of the International Space and Planetary Environment Science Center (i-SPES) at Kyushu University has discovered an anomalous increase in oxygen ions (O+) in near-Earth space during a huge magnetic storm on May 10-11, 2024, by combining ground magnetometer observation networks mainly in New Zealand and observation data from JAXA's geospace satellite “ARASE”.
The analysis revealed that an extremely high density state with a plasma mass density of about 35,000 amu/cm3 occurred in space above New Zealand at about 2.2 times the Earth's radius. Furthermore, analysis in combination with electron density observations by the ARASE satellite indicates that the average ion mass in this region reached about 15 amu, indicating that more than 90% of the plasma may have been occupied by oxygen ions.
The increase in oxygen ions is usually observed in the relatively outward region of 3-5 times the Earth's radius during the recovery phase of a magnetic storm, and the percentage of oxygen ions in this region is estimated to be about 10-20%. In contrast, the present study indicates that O+ may account for more than 90% of the O+ in the vicinity of 2.2 times the Earth's radius during the main phase of a magnetic storm, which is an extreme condition that has not been expected in the past.
Furthermore, observations by the ARASE and DMSP satellites confirmed the coexistence of relatively energetic ions of several keV and cold high-density plasma, as well as a decrease in the total ionospheric electron count (TEC) and an increase in ionospheric electron temperature. These results indicate that oxygen ions may have been efficiently supplied from the ionosphere via electron heating by relatively energetic ions, suggesting the existence of a new O+ supply mechanism.
The findings are expected to greatly advance our understanding of the space environment around the Earth during giant magnetic storms and contribute to space weather research related to satellite failures and energetic particle environmental changes.
The research results were published in the international journal Earth, Planets and Space, published by Springer Nature, on Saturday, May 23, 2026 (local time).
The journal is published in the journal Earth, Planets and Space, published by Springer Nature.
Related Links
Kyushu University
Journals
| Journal name |
Earth, Planets and Space (Springer Nature)
|
|---|---|
| Title of paper |
Extreme O+ Enrichment in the Deep Inner Magnetosphere: The May 2024 Geomagnetic Storm |