Relativistic electron pitch‐angle scattering by electromagnetic ion cyclotron waves during geomagnetic storms
Bibliographic record
Abstract
During magnetic storms, relativistic electrons execute nearly circular orbits about the Earth and traverse a spatially confined zone within the duskside plasmapause where electromagnetic ion cyclotron (EMIC) waves are preferentially excited. We examine the mechanism of electron pitch‐angle diffusion by gyroresonant interaction with EMIC waves as a cause of relativistic electron precipitation loss from the outer radiation belt. Detailed calculations are carried out of electron cyclotron resonant pitch‐angle diffusion coefficients D αα for EMIC waves in a multi‐ion (H + , He + , O + ) plasma. A simple functional form for D αα is used, based on quasi‐linear theory that is valid for parallel‐propagating, small‐amplitude electromagnetic waves of general spectral density. For typical observed EMIC wave amplitudes (1–10 nT ), the rates of resonant pitch‐angle diffusion are close to the limit of “strong” diffusion, leading to intense electron precipitation. In order for gyroresonance to take place, electrons must possess a minimum kinetic energy E min which depends on the value of the ratio (electron plasma frequency/electron gyrofrequency); E min also depends on the properties of the EMIC wave spectrum and the ion composition. Geophysically interesting scattering, with E min comparable to 1 MeV, can only occur in regions where (electron plasma frequency/electron gyrofrequency) ≥10, which typically occurs within the duskside plasmapause. Under such conditions, electrons with energy ≥1 MeV can be removed from the outer radiation belt by EMIC wave scattering during a magnetic storm over a time‐scale of several hours to a day.
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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 | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| 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".