Radar Observations of Flows Leading to Longitudinal Expansion of Substorm Onset Over Alaska
Bibliographic record
Abstract
Abstract Longitudinal expansion of brightening of the substorm onset arc likely represents longitudinal expansion of the substorm onset instability. We used Poker Flat radar campaign auroral observations to identify seven substorm onsets seen east or west of the radar that expanded into the radar field‐of‐view. The radar observations were used to show flows relative to the expanding onset aurora. Flow enhancements were found equatorward (poleward) of the westward (eastward) longitudinal expansion of the onset arc brightening that agree with plasma sheet bubble modeling. This lends significant additional supporting evidence that an incoming reduced entropy flow channel leads to onset. As a flow channel enters the auroral oval (plasma sheet) from the polar cap (magnetotail lobes) and starts to move equatorward (earthward in the plasma sheet) as a bubble, it simultaneously expands azimuthally due to the combination of electric drift along dawnward tilted equipotentials and westward magnetic drift of more energetic ions. As the azimuthally expanding bubble reaches near the equatorward boundary of the electron auroral oval, it leads to the onset instability indicated by the auroral beading and associated flows if conditions are appropriate. The instability grows in the initial onset region, as it simultaneously extends longitudinally with the continued azimuthal expansion of the bubble within the plasma sheet. Additionally, after onset, the auroral bulge expands poleward and can lead to a westward traveling surge. We observe strong flows heading toward the front of the surge that appear to bring low entropy plasma, perhaps from the polar cap, into the surge.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 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 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".