Truncation of the Earth Impulse Responses Relating Geoelectric Fields and Geomagnetic Field Variations
Bibliographic record
Abstract
To assess the geomagnetic hazard to power systems, it is necessary to model the Geomagnetically Induced Currents (GIC) produced during space weather storms.This requires knowledge of the geoelectric fields that drive GIC.In the time domain, the geoelectric fields can be calculated using a convolution integral including the geomagnetic field or its time derivative and an impulse response function for the Earth.In principle, the integral extends to infinity but for practical calculations the impulse responses must be truncated at a finite length.In this paper, we investigate the effects of the truncation on the calculation of the geoelectric fields.We consider how long the impulse responses need to be to obtain sufficiently accurate geoelectric field values.It is found that the high-pass impulse response used with geomagnetic data can be truncated very early, e.g. at 1 h, while the low-pass impulse response used with geomagnetic time derivative data must be extended much longer, e.g. until 24 h.
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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 | 0.001 | 0.007 |
| 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 | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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".