The Effect of the Canadian Shield on Cloud-to-Ground Lightning Density
Bibliographic record
Abstract
The Canadian Shield is a large area of exposed bedrock that covers a significant portion of Canada. The focus of this research is on the Canadian Shield in northeastern regions of the Canadian Prairie provinces, the Northwest Territories, and northwestern Ontario. Observations of cloud-to-ground lightning flashes show a distinct reduction in lightning density when crossing the southern boundary of the Canadian Shield. Statistical tests were used to determine whether there was a statistically significant change between the average cloud-to-ground lightning density gradient near the Canadian Shield and away from it. Most regions had a statistically significant change at the 95% confidence level across the boundary. However, regions that contained large lakes or significant topography did not, suggesting that the large open water and rough topography have a greater effect than the Canadian Shield.Three reasons for the distinct change across the Canadian Shield were explored: less lightning is detected, less lightning occurs with the same number of thunderstorms, and less lightning occurs because fewer thunderstorms occur. Some evidence suggested that less lightning is detected because the Canadian Shield has lower electrical conductivity. The low conductivity distorts the lightning waveform and contributes to higher errors and lower detection efficiency. There is also some evidence that a sharp change in land cover from lusher, higher transpiring forest to sparser lower transpiring forest could be reducing the instability causing fewer, weaker thunderstorms.
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".