Validating the performance of the Empirical Canadian High Arctic Ionospheric Model (E-CHAIM) with in situ observations from DMSP and CHAMP
Bibliographic record
Abstract
The Empirical Canadian High Arctic Ionospheric Model (E-CHAIM) is a new empirical model of high latitude ionospheric electron density. While the introductory studies regarding E-CHAIM include validations, E-CHAIM’s topside model was notably excluded from independent validation using datasets not included in the model fitting. In this study, we undertake such a validation using in situ electron density observations from the Defense Meteorological Satellite Program (DMSP) constellation of satellites and the Challenging Mini-satellite Payload (CHAMP) mission. Through this validation, we show that E-CHAIM generally outperforms the International Reference Ionosphere (IRI) at DMSP orbit (~830 km altitude), with RMS errors of 8.3–9.8 × 10 9 e/m 3 versus the IRI’s 1.2–1.3 × 10 10 e/m 3 . E-CHAIM’s improvement over the IRI is consistent at all latitudes but is particularly noted in sub-auroral regions and is mainly limited to summer and equinox periods. At CHAMP orbit, E-CHAIM and the IRI are found to perform largely comparably, with E-CHAIM outperforming the IRI only marginally with RMS errors of 7.11 × 10 10 e/m 3 versus the IRI’s 7.48 × 10 10 e/m 3 . This improvement is found to be largely constrained to sub-auroral latitudes with both models performing comparably at higher latitudes. An observed tendency for the IRI to overestimate electron density in the near-peak (at CHAMP orbit) and underestimate electron density at higher altitudes (DMSP orbit) appears to be consistent with previous work, which identified this pattern to result from shortcomings in the NeQuick topside function curvature at high latitudes.
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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) | 0.000 | 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) | 0.000 | 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".