Variability in HDO/H<sub>2</sub>O abundance ratios in the tropical tropopause layer
Bibliographic record
Abstract
The dehydration of air in the tropical tropopause layer (TTL) and mechanisms for the entry of water vapor into the stratosphere are investigated by an analysis of ACE‐FTS profiles of temperature, water vapor, and the ratio [HDO]/[H2O] expressed in δD notation. Month‐to‐month comparisons indicate greater seasonal variability than interannual variability between 25°S–25°N, thus comparisons are made between February, April, August, and October averages for the years 2004 and 2005 combined. The data indicate a pattern of seasonal variability which is clearer in the Northern Hemisphere tropics and a relationship between minimum temperature, minimum water vapor, and maximum HDO depletion, which exists beyond the estimated uncertainty in these values. The range of values observed for HDO depletion and comparisons to modeled Rayleigh distillation curves indicate an important contribution from convection in addition to gradual dehydration. Multiple factors including the shape of the δD profiles suggest that a likely mechanism for the convective influence is the lofting of ice particles in the tropical troposphere.
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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 | 0.000 | 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".