Multispacecraft observations of fundamental poloidal waves without ground magnetic signatures
Bibliographic record
Abstract
Abstract Poloidal standing Alfvén waves observed by spacecraft usually have a second harmonic standing wave structure. On very rare occasions, fundamental poloidal waves have been observed in association with giant pulsations observed on the ground. In this paper, we report multisatellite observations of fundamental poloidal waves that did not produce any clearly associated magnetic pulsations on the ground. The waves were observed on 10 November 2008, at ~1830 Universal Time (UT) at THEMIS‐A and THEMIS‐D and at ~2010 UT at THEMIS‐E as these spacecraft passed L ~ 11 and magnetic local time (MLT) ~ 0900. The GOES‐11 geostationary satellite ( L ~ 7) also observed poloidal waves at ~1730 UT when it was at ~0900 MLT. The poloidal waves at THEMIS were characterized by narrow‐band oscillations (frequency ~4 mHz) of the ion bulk velocity and magnetic field in the radial direction. We identify the waves at THEMIS to be the fundamental mode on the basis of the wave properties observed slightly south of the magnetic equator: large velocity amplitude, small magnetic field amplitude, and ~90° phase delay of the magnetic field relative to the velocity. The azimuthal wave number is found to be ~70 (if we assume westward propagation) or ~200 (if we assume eastward propagation) from the phase delay between THEMIS‐A and THEMIS‐D. This wave number explains why there were no corresponding magnetic field oscillations on the ground. These observations imply that only a subset of fundamental poloidal waves excited in the magnetosphere is observed on the ground as giant pulsations.
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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 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 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 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".