Dry deposition of individual nitrogen species at eight Canadian rural sites
Bibliographic record
Abstract
Three nitrogen species in air, HNO3, particle nitrate (pNO3−), and particle ammonium (pNH4+), have been routinely measured for estimating nitrogen dry deposition in the Canadian Air and Precipitation Monitoring Network (CAPMoN) and the U.S. Clean Air Status and Trends Network (CASNET) for several decades. To investigate the relative contributions of other nitrogen species to total nitrogen dry and dry + wet deposition, 14 short‐term field campaigns were conducted between 2001 and 2005 at eight selected rural sites across eastern Canada. Air concentrations were measured for the total oxidized nitrogen (NOy) and major species comprising NOy (NO, NO2, PAN, PPN, HNO3, pNO3−), and for the two reduced nitrogen species (NH3, pNH4+). Dry deposition fluxes of NOy and NHx (= NH3 + pNH4+) were then estimated by combining measured concentrations of individual nitrogen species with their respective dry deposition velocities estimated from big‐leaf models using on‐site meteorological measurements. Nitrogen dry deposition were estimated to be 0.8–4.0 kg N ha−1 a−1, depending on location, with 60–75% from NOy and 25–40% from NHx. HNO3 and NO2 dominated NOy dry deposition while NH3 and pNH4+ contributed equally to NHx dry deposition. The pNO3−, PAN, and unidentified NOy species also contributed appreciable amounts to NOy dry deposition. Nitrogen dry + wet deposition from NOy + NHx was estimated at 4.3–11 kg N ha−1 a−1, with dry deposition accounting for 10–50%. The routinely monitored species accounted for less than 50% of total N dry deposition; thus, total dry + wet deposition from the Canadian monitoring network had a lower bias by 5–25% at most of the sites.
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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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.002 | 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) | 0.001 | 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".