A trajectory study into the origin of spring time Arctic boundary layer ozone depletion
Bibliographic record
Abstract
In polar regions, severe marine boundary layer ozone depletion episodes (ODEs) are a yearly recurring phenomenon in the spring. Using 9 years of 10‐day three‐dimensional trajectory calculations, the origin of ODEs at three Arctic observatories is investigated. The analysis indicates that marginal ice zones are potential source regions of ODEs. Those regions do broadly correspond to areas where increased levels of bromine oxide (BrO), an indicator of ozone depletion chemistry, are observed by the GOME satellite. The source region of ODEs, observed at Barrow, Alaska, is found to be about 1 day's travel upwind, in agreement with expectations based on the rate at which O3 depletion chemistry occurs. In contrast, the likely source region for ODEs observed at Alert, Canada, and Zeppelinfjellet, Norway, appears to be located several days' travel upwind, off the Siberian coast. This result may reflect the absence of favorable ice conditions for O3 depletion chemistry nearer those sites. Assuming that O3 depletion occurs at those regions, this implies that air parcels without O3 remain that way for several days or the depletion is slower than current understanding of the O3 depletion chemistry suggests. Rapid changes in O3 mole fractions at those measurement sites appears not to be an indication of fast chemical destruction of ozone but rather are due to abrupt air mass changes. Data for September indicate a much narrower distribution of ozone mole fractions and no particular pattern linking a preferred area with lower mole fractions.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 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".