Intermingled Open and Closed Magnetic Field Lines near the Radial Origin of the Heliospheric Current Sheet
Bibliographic record
Abstract
Abstract On 2024 March 30, the Parker Solar Probe crossed the heliospheric current sheet at 13 solar radii while encountering two distinctly different regions at sharp boundaries on several occasions. The two regions had very different plasma densities, electric-field spectra, and magnetic-field geometries. In one region the strahl flowed only along the direction from the Sun, and there were relatively few particles at pitch angles near 90°, while in the other region the strahl flowed both toward and away from the Sun, and there were relatively many particles at pitch angles near 90°. These different properties are interpreted as being due to the spacecraft being in the heliospheric current sheet on long open magnetic field lines in the case of unidirectional strahl flow and the spacecraft being in coronal loops having much shorter closed magnetic field lines in the case with bidirectional strahl flow. The two regions intermingled on time scales less than 100 ms to create a complex magnetic field geometry. Broadband waves were observed in the open field-line regions, while narrowband electrostatic harmonic waves were observed in both regions. These harmonic frequencies correlated with the proton plasma frequency, f pp, with the lowest frequency at ∼0.1f pp. This result, plus the field-aligned electric field waves and plasma density fluctuations, requires that the observed electrostatic mode and associated harmonics were ion acoustic waves.
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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 | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".