On the bow shock θ<sub><i>Bn</i></sub> dependence of upstream 70 keV to 2 MeV ion fluxes
Bibliographic record
Abstract
We present a statistical study of 216 energetic ion events observed just upstream of Earth's bow shock by the Wind spacecraft. The ions that compose this database range in energy from 27 keV to 2 MeV. Of particular interest is the effect of shock geometry on the properties of the energetic ions. Our approach is different from previous studies in that we only include upstream ion events associated with a local bow shock crossing. In this way we determine the shock geometry locally, rather than from extrapolations of remote upstream observations to a model shock source location, providing a better quantitative determination of the properties of the energetic ions in relation to shock geometry. Under typical interplanetary conditions in the absence of a preexisting population of ambient energetic ions ( E ≥ 50 keV), we find that the ion energy spectrum is characterized by an energy cutoff at ∼200–330 keV. Neither the energy cutoff nor the energetic ion spectrum show any dependence on shock geometry as measured by the angle between the shock normal and magnetic field θ Bn . However, when an ambient population of energetic particles is present in the interplanetary medium, ion flux levels measured just upstream of the terrestrial shock reach a minimum near θ Bn ∼ 45° irrespective of energy. The energy spectrum spans up to ∼2 MeV. Moreover, ions with energies E ≥ 550 keV are observed only at θ Bn ≥ 45°. The flux levels of these more energetic ions increase, in an average sense, with increasing values of θ Bn . Lee 's [1982] self‐consistent theory of ion diffusive shock acceleration appears to explain the energetic ion flux levels observed at θ Bn ≤ 40°. Upstream energetic ions with energies E ≥ 550 keV appear to be the result of shock drift acceleration.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| 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".