Iodine-129,<sup>137</sup>Cs, and CFC-11 tracer transit time distributions in the Arctic Ocean
Bibliographic record
Abstract
[1] Time series measurements of the nuclear fuel reprocessing tracers, 129I and 137Cs, and ventilation tracer, CFC-11, were used to determine circulation time scales for Atlantic Water (AW) in the Arctic Ocean. Measurements in surface water are consistent with an advection model and transit times from the North Sea of 1–4 years to the Barents Sea, 3–6 years to the Kara Sea, and 9–12 years to the North Pole. Tracer ages for intermediate waters do not support an advection model because they vary with time. The tracer relationships were employed to determine transit time distributions (TTD), using inverse Gaussian functions, that implicitly incorporate the effects of mixing in simulating fluid flow. Tracer concentrations were used to constrain the ratio of the width, Δ, of the TTD to the mean age, Γ, a measure of the relative importance of mixing, giving values for most intermediate water regimes of Δ/Γ ≤ 1. These results are in contrast to values, Δ/Γ 1 typical of the North Atlantic, indicating the greater relative importance of advection compared to mixing in the Arctic Ocean. Mean ages for AW increase from 12–20 years in the southern Makarov Basin to 30–40 years near the Arctic outflow north of Greenland. A decline in Δ/Γ with distance along the direction of AW boundary flow from the Makarov into the Canada Basin may indicate relatively stronger mixing in regimes upstream of the Makarov Basin but also implies that TTDs may differ from inverse Gaussian functions for flow in the Arctic domain.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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".