Distinguishing Subauroral Ion Drifts From Birkeland Current Boundary Flows
Bibliographic record
Abstract
Abstract The Swarm satellites regularly observe latitudinally narrow ion velocity jets exceeding 1 km/s relative to the surrounding plasma at high latitude. Two distinct categories of duskward directed flow channels are observed. The most common are situated between the Region 1 and Region 2 currents, are observed primarily during quiet geomagnetic conditions, and are called Birkeland current boundary flows. During active conditions, a second type of duskward directed ion velocity jet is observed at the equatorward edge of the Region 2 currents, colocated with a sharp poleward directed plasma density gradient, consistent with subauroral ion drifts. Pedersen current and electric field estimates from the Swarm satellites show both types of flow channel to be associated with low height‐integrated Pedersen conductivity relative to the surrounding plasma. In this study we show two cases in which the Swarm satellites passed through both types of event on the same orbit, as well as the average ion velocity, field‐aligned current, and plasma density surrounding 57 of these events. Some field‐aligned current morphologies previously associated with subauroral ion drifts suggest that they may have instead been Birkeland current boundary flows. In this study we provide a comparative description of both phenomena to facilitate their distinction in future studies.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| 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".