Observed distribution of halocarbons in the Southern Hemispheric UTLS and implications for the bromine and chlorine budget of the lowermost stratosphere
Bibliographic record
Abstract
Since the end of the 1980's, the Montreal Protocol regulates production and use of chlorine and bromine containing substances because they thin out the ozone layer. This has led to a phase out of the long-lived halocarbons like the chlorofluorocarbons (CFCs). Next to the long-lived halocarbons, bromine and chlorine containing substances with atmospheric lifetimes of less than 6 months can reach the lower stratosphere. These substances, also known as "very short-lived" substances (VSLS), have their origin both from natural and anthropogenic sources. An increase of the relative contribution of the VSLS to the stratospheric halogen loading is assumed. Due to their short lifetime, chlorine and bromine of these gases are released quickly into the stratosphere, making them particularly effective catalysts for destruction of ozone in the lower stratosphere. Here we present airborne measurements of halocarbons including chlorine and bromine VSL source gases. Measurements were taken on the HALO aircraft during the measurement campaign SOUTHTRAC in the Southern Hemisphere UTLS. Using an airborne GC/MS system in electron impact ionization mode, samples were taken in a time resolution of around 6 minutes. One of the focuses are the exchange processes between the Northern and Southern Hemisphere. We further compare results of this campaign with these of previous ones of the Northern Hemisphere.
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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 | 0.000 | 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".