High sulphur dioxide deposition velocities measured with the flux/gradient technique in a boreal forest in the Alberta oil sands region
Bibliographic record
Abstract
Abstract. The emission of SO2 from the Athabasca oil sands region (AOSR) has been shown to impact the surrounding forest area and human exposure. Recent studies using aircraft-based measurements have demonstrated that deposition of SO2 to the forest is at a rate many times higher than model estimates. Here we use the flux/gradient method to estimate SO2 deposition rates at two tower sites in the boreal forest downwind of AOSR SO2 emissions. We use both continuous and passive sampler measurements and compare both techniques. The measurements predict SO2 deposition velocities ranging from 2.1–5.9 cm s-1. There are uncertainties associated with the passive sampler flux/gradient analysis, primarily due to an assumed Schmidt number, a required assumption of independent variables, and potential wind effects. We estimate the total uncertainty as ±2 cm s-1. Accounting for these uncertainties, the measurements are near (or slightly higher than) the previous aircraft-based measurements (1.2–3.2 cm s-1) and significantly higher than model estimates for the same measurement periods (0.1–0.6 cm s-1), suggesting that SO2 has a much shorter lifetime in the atmosphere than is currently predicted by models.
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 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 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".