Substorm-time magnetic field perturbations in the polar magnetosphere: POLAR observations
Bibliographic record
Abstract
We present a case study of substorm-time magnetic field perturbations in the high-altitude polar magnetosphere, corresponding to the polar lobe, using data from the POLAR spacecraft together with ground-based CANOPUS observations and WIND solar-wind observations. The substorm of this paper had a clear growth phase and one clear major expansion onset, enabling an unmistakable comparison of the substorm timings and those of the magnetic field perturbations observed by POLAR. During the growth phase, the magnetic field strength ( B total ) increased and the flaring angle of the field line decreased at POLAR: They are ascribed to the pileup of magnetic field lines over the polar magnetosphere and to the braking effect of the ionosphere on the tailward motion of the piled-up field lines, respectively. For ∼ 28 min after the expansion onset, B total at POLAR did not decrease toward its presubstorm value, in contrast to past tail-lobe observations where B total decreased during the expansion phase. This absence of the field-decrease signature in the polar lobe for ∼ 28 min, reported for the first time in this paper, could be ascribed to dipolarization/compression of the inner magnetosphere during the expansion phase, cancelling the field-decreasing effect.
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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 | 0.001 | 0.001 |
| 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".