Characteristics of Summertime Volatile Organic Compounds in the Lower Free Troposphere: Background Measurements at Mt. Fuji
Bibliographic record
Abstract
Air samples were collected at Mt. Fuji Research Station (FRS) for the measurements of volatile organic compounds (VOCs) in the summers of 2015 and 2016. In this study, 24 compounds were analyzed, of which only 12 halocarbons were quantified in 2015. The average total concentrations of target VOCs were 2.62 ± 1.38 and 2.99 ± 0.95 ppb in 2015 and 2016, respectively. The concentrations of individual VOCs ranged from a few ppt to a few ppb, indicating a highly inhomogeneous feature at the FRS. A cluster analysis of 3-day backward trajectories was performed for the sampling time. Except for the aromatic compounds, the VOCs showed relatively low concentrations in association with air masses originating from the coastal region in the low latitudes (15°N–35°N) of East Asia in 2015. By contrast, the clusters with elevated VOC concentrations mainly came from the high latitudes (35°N–60°N) of the Asian continent in 2016. No particular diurnal pattern was found for VOCs and CO, which might have resulted from suppressed mountain-valley winds at the FRS. Halocarbons regulated by the Montreal Protocol showed low variability and were in favorable agreement with background values at the Gosan station (GSN) and those reported in the literature. Other partially halogenated compounds with higher variability, such as CH3Cl and CHCl3, showed discrepancies at the FRS and GSN. 1,2-dichloroethane (R-150), 1,1-dichloroethane (R-150a), and 1,4-dichlorobenzene (p-DCB) were also measured at the FRS with concentrations of 24 ± 14, 38 ± 13, and 13 ± 10 ppt, respectively, in 2015. A close relationship between n-pentane and i-pentane with R2 more than 0.85 was found in both 2015 and 2016. Low ratios of n/i-pentane ranging from 0.25 to 0.67 were observed in the free troposphere at the FRS, comparable to most mountain stations.
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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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 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".