Inference of Hydroxyl Radical Abundances from Combined Satellite and Ground-Based Hydrochlorofluorocarbon Observations
Bibliographic record
Abstract
Until recently, Methyl Chloroform was used as a bellwether to determine OH levels but due to its declining concentrations, the need for other means to calculate OH levels is imminent.This work proposes a new way of using three different tracers (HFC134a, HCFC141b, and HCFC142b) to determine hydroxyl levels in the atmosphere using a 9box model.The annual trends of each gas were obtained and it was found that there has not been a significant drop but an increase in two of the tracers' levels despite the implementation of Montreal Protocol.The tropopause was defined around 13kms in the northern and southern latitudes and around 17kms in the tropics.With the regions of each box defined, and the concentrations of the tracers obtained from ACE-FTS instrument and NOAA, the OH levels in the atmosphere were obtained through least-squares estimation.The surface regions showed the closest estimates at 5.35 x 10 5 molecules/cm 3 over the tropics and around 1.1 x 10 5 molecules/cm 3 over the other two bands.The global averages across troposphere and stratosphere were about 10 and 12 times lower than the traditionally observed values of about 10 x 10 5 molecules/cm 3 and 1 x 10 5 molecules/cm 3 .However, future works could potentially lead to the model observing closer estimates.
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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 | 0.000 |
| 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".