Rapid improvement of lake acid–base status in Atlantic Canada following steep decline in precipitation acidity
Bibliographic record
Abstract
Policy measures resulted in reductions in acidic emission of sulfur and nitrogen in North America. Here, we conducted trend analyses on a 37-year database for atmospheric depositions and lake ( n = 78) chemistry in the provinces of Nova Scotia, New Brunswick, and Newfoundland and Labrador, in Canada. Sulfate, and particularly nitrate deposition, began to decrease strongly around the year 2000, resulting in strong pH increases in precipitation. Recovery was observed in most lakes with significant increases in pH and Gran alkalinity (AlcG). A piecewise regression approach detected coherent breaks and overlapping confidence intervals in the break years for precipitation pH and lake AlcG (to a lesser extent for lake pH), suggesting a rapid lake response to the sudden changes in acidic inputs. However, an increase in organic acid after 2000 decreases the rate of acid neutralizing capacity recovery nearly by half in about a third of the studied lakes. Despite the positive pH and AlcG trends, a significant proportion of lakes still have pH and calcium values below the recommended thresholds for aquatic life.
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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 | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 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".