A UT/LS ozone climatology of the nineteen seventies deduced from the GASP aircraft measurement program
Bibliographic record
Abstract
Abstract. The knowledge of historical ozone in the upper troposphere/lower stratosphere (UT/LS) region is mostly confined to regular measurements from a number of ozonesonde stations. We present ozone measurements of the Global Atmospheric Sampling Program (GASP) performed from four commercial and one research aircraft during 1975 to 1979. Using GASP data, a UT/LS ozone climatology of 1975–1979 was built. Seasonality and concentrations of GASP UT ozone in the middle, subtropical and tropical regions of the northern hemisphere (NH) are generally in agreement with other published observations, derived from ozonesondes or aircraft campaigns. In regions where both GASP (1970s) and MOZAIC (1990s) data are available, similar ozone concentrations are found and seasonal cycles agree well confirming the reliability of GASP ozone. GASP provides unique large-scale climatological information on UT/LS ozone above the NH Pacific region. Agreement is found with observations from individual ozonesonde sites and aircraft campaigns carried out over this region. Tropical UT ozone is seen to be lower near the dateline than further east, presumably related to uplift of ozone poor air within convection. Over the west coast of the United States, summer UT ozone is higher than over the adjacent Pacific, probably caused by air pollution over southern California in the 1970s. GASP offers an unprecedented opportunity to link to European, Canadian and U.S. American ozonesonde observations of the 1970s. For the quantitative comparison, an altitude offset was applied to the sonde data to account for the slow response time of the sensors. In the LS, the European and Canadian Brewer-Mast (BM) sensors then agree to ±10% with the GASP instruments in all seasons. In the UT, the European BM sondes record similar to slightly less average ozone than GASP, however, with large variability overlaid. Over the eastern United States, systematic positive deviations of the Wallops Island ECC sondes from GASP of +20% are found. The comparisons over Europe and the eastern United States corroborate earlier findings that the early ECC sensors may have measured 10 to 25% more ozone than the BM sensors. Our results further indicate that applying the correction factor to the 1970s BM ozonesondes is necessary to yield reliable ozone mixing ratios in the UT/LS.
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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 | 0.002 | 0.002 |
| 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".