Long‐term change of CO<sub>2</sub> latitudinal distribution in the upper troposphere
Bibliographic record
Abstract
Abstract We analyzed temporal variations in the annual mean latitudinal distribution of upper tropospheric CO 2 using the aircraft measurements taken between Japan and Australia over the period 1993–2013, plus earlier data from 1984 and 1985. The observed CO 2 latitudinal gradient between 30°N and 30°S showed large interannual variations that are clearly associated with El Niño–Southern Oscillation events. We also found long‐term increasing trends of the CO 2 gradients in the most northern latitudes that are proportionally associated with increasing fossil fuel emissions, while decreasing trends were found around the tropical regions. Extrapolation of the changes in the CO 2 gradient back to zero fossil fuel emissions showed a negative north‐south gradient with lower CO 2 in the Northern Hemisphere than in the Southern Hemisphere, as well as a regional CO 2 elevation in the tropical regions. These features provide a useful constraint on model estimates of CO 2 fluxes from the ocean and the land biosphere.
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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 | 0.001 |
| 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".