Atomic oxygen retrievals in the MLT region from SCIAMACHY nightglow limb measurements
Bibliographic record
Abstract
Abstract. Vertical profiles of atomic oxygen concentration in the mesosphere and lower thermosphere (MLT) region were retrieved from sun-synchronous SCIAMACHY/Envisat limb observations of the oxygen 557.7 nm green line emission occurring in the terrestrial nightglow. A band pass filter with noise detection was applied to eliminate contributions from other emissions, the impact of noise and auroral activity. Assuming horizontal homogeneity of each atmospheric layer, and absence of absorption and scattering, vertical volume emission rate profiles were retrieved from integrated limb emission rate profiles. The radiative transfer problem was treated with a linear forward model and inverted using regularized total least squares minimization. Atomic oxygen concentration ([O]) profiles were retrieved at altitudes from 85 to 105 km with approximately 4 km vertical resolution for the period from August 2002 to April 2012 at a constant local time (LT) of approximately 22:00. The retrieval of [O] profiles was based on the generally accepted 2-step Barth transfer scheme including consideration of quenching processes and the use of different available sources of temperature and atmospheric density profiles. A sensitivity analysis was performed for the retrieved [O] profiles to estimate the maximum uncertainty, assuming independent contributions of uncertainty components. The retrieved [O] profiles were compared with reference [O] profiles measured by SABER/TIMED and modelled using NRLMSISE-00 and SD-WACCM4. A comparison of the retrieved [O] profiles with the reference [O] profiles enabled the selection of the most appropriate photochemical model accounting for quenching processes and the most appropriate source of temperature and density profiles for further application of our approach to the [O] profile retrieval. The obtained [O] profile time series show characteristic seasonal variations in agreement with atmospheric models and satellite observations based on analysis of OH Meinel band emissions. Furthermore, a pronounced 11 year solar cycle variation can be identified in the atomic oxygen concentration time series, which will be the subject of further studies.
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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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 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".