Excitation and steepening of ion‐acoustic waves in the ionospheric Alfvén resonator
Bibliographic record
Abstract
A nonlinear two‐dimensional fluid model describing excitation of the ionospheric Alfvén resonator by a shear Alfvén wave coming from the magnetosphere is developed. Initially, the plasma is in an equilibrium defined by a balance between the gravity, electric field, and pressure gradient forces. This equilibrium is perturbed when a standing Alfvén wave is excited in the resonator. The nonlinear Lorentz force of the wave creates converging and diverging plasma flows along the geomagnetic field, thus producing compressions and rarefactions in the plasma density. Simulation reveals that density perturbations evolve into ion‐acoustic shock waves in a process similar to the nonlinear steepening of sound waves in neutral gases. A shock associated with compression of hydrogen ions propagates faster than a shock associated with compression of oxygen ions. One‐dimensional shock‐capturing Poisson simulation reveals that the shocks appear as double layers at first, but then they decay into ion‐acoustic wave packets. The drop of potential across each shock is negligible at any stage of shock's development, making these shocks unfavorable for auroral electron acceleration.
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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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| 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) | 0.001 | 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".