Open‐closed field line boundary position: A parametric study using an MHD model
Bibliographic record
Abstract
In this paper we investigate the effect of changes in the interplanetary magnetic field (IMF), solar wind dynamic pressure, and dipole tilt angle on the position of the ionospheric projection of the open‐closed field line boundary (OCB) in a magnetohydrodynamic (MHD) model. We carry out a large number of steady state global MHD simulations in order to parameterize the OCB as a function of the solar wind By and Bz which we find to have the largest effect on the OCB location. We interpolate between the values produced by the simulations, which allows us to evaluate the location of the OCB projection into the ionosphere for any values of ∣By∣ < 10 nT and ∣Bz∣ < 10 nT. It is found that, particularly on the nightside, the OCB position is very sensitive to changes in the northward IMF component Bz, but it is much less sensitive to changes in Bz when it is southward. The response of the OCB location to changes in By also depends greatly on whether Bz is northward or southward, being much larger in situations in which Bz > 0 nT. We also find that the polar cap area increases with the increasing solar wind dynamic pressure. The Bx component of the IMF and the dipole tilt angle are found to have relatively small effects on the location of the OCB.
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| 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".