Total hydrogen budget of the equatorial upper stratosphere
Bibliographic record
Abstract
Water vapor and methane mixing ratios measured by the Halogen Occultation Experiment (HALOE), the Atmospheric Chemistry Experiment (ACE), and the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) along with simulations from the NRL CHEM2D middle atmosphere model are used to study the hydrogen budget in the equatorial upper stratosphere. Multiyear time series of equatorial upper stratospheric H2O + 2*CH4 show temporal variations during periods of relative long‐term stability in water vapor and methane entering the stratosphere. These variations, which are anticorrelated to CH4, are quasibiennial and seasonal in nature, and peak near 2 hPa with a magnitude of 3% of the H2O + 2*CH4 mixing ratio. We find that the ratio of the changes in water vapor to the changes in methane is consistently >2 over the entire equatorial upper stratosphere in HALOE, ACE, and MIPAS data. Ratios of the H2O to CH4 changes calculated from the CHEM2D model are similar, but slightly smaller, and the variations in H2O + 2*CH4 are balanced by nearly equivalent variations in molecular hydrogen. We use this relationship to infer molecular hydrogen mixing ratios from the observations which show that its mixing ratio decreases with altitude above 5 hPa. This net loss in molecular hydrogen drives additional water vapor production so that multiyear average profiles of H2O + 2*CH4 from HALOE, ACE, and MIPAS show an ∼0.4 ppmv increase between 5 hPa and 1.5 hPa, so that total hydrogen is conserved. Collectively, these results illustrate the importance of molecular hydrogen in the equatorial upper stratospheric hydrogen budget.
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 | 0.000 |
| 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".