Midlatitude ionospheric disturbances during magnetic storms and substorms
Bibliographic record
Abstract
We present periodic (∼2 hour) magnetospheric and ionospheric oscillations observed with multiple space‐based and ground‐based instruments during the severe magnetic storm of 25 September 1998. Periodic particle injections were observed at geosynchronous orbit. Ground magnetometers registered very large, as high as 3000 nT, magnetic deviations in the nightside auroral zone. The Millstone Hill incoherent scatter radar at magnetic latitude 55° measured periodic enhancements of ionospheric eastward ion velocity from midnight to ∼1000 MLT. The periodic variations in the magnetometers and Millstone Hill radar were well correlated with the magnetospheric particle injections. The observations are consistent with the occurrence of periodic magnetospheric substorms during a magnetic storm. During each substorm cycle the ionospheric auroral zone expanded to the latitude of the Millstone Hill radar, so the radar was periodically within the auroral zone and detected the auroral plasma return flows. After substorm activity stopped, the Millstone Hill radar measured near‐noon in‐phase periodic oscillations of the ionospheric F‐region electron density and temperature, which may be due to particle precipitation from the ring current and/or plasmasphere into the midlatitude ionosphere. We suggest that magnetospheric substorms during magnetic storms have a cycle time of ∼2 hours. The magnetosphere can sustain similar oscillations for several cycles even though the substorm activity has stopped. All the observed periodic variations in the geosynchronous particle injections, in the auroral magnetic deviations, and in the ionospheric ion velocity are related to the periodic magnetospheric substorms and oscillations.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".