Postbomb Subtropical North Pacific Surface Water Radiocarbon History
Bibliographic record
Abstract
Abstract We have generated a high‐resolution coral Δ14C record from the leeward side of the Big Island of Hawai’i in the subtropical North Pacific. The record spans 1947–1992, when the coral was collected, and includes a brief prebomb interval as well as the postbomb era. Mean prebomb (1947–1954) values average −55‰ (±1, SE of the mean) with a clear seasonal cycle. Values are less positive during winter when vertical exchange mixes surface and lower‐14C subsurface waters. The postbomb annual maximum occurs in 1971 (+160‰) and decreases in a series of shifts to +105‰ in 1991, the end of our coral‐based reconstruction. The decrease is not monotonic and has inflection points during the La Niña years of 1973, 1977, and 1984. Imbedded in the Δ14C record is interannual variability in the El Nino‐Southern Oscillation band which is interpreted to reflect the lateral advection of low latitude surface waters as part of the oceanic Hadley Cell driven by Sverdrup dynamics.
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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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 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) | 0.003 | 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".