Signal strength and climate calibration of a European tree‐ring isotope network
Bibliographic record
Abstract
We present the first European network of tree ring δ 13 C and δ 18 O, containing 23 sites from Finland to Morocco. Common climate signals are found over broad climatic‐ecological ranges. In temperate regions we find positive correlations with summer maximum temperatures and negative correlations with summer precipitation and Palmer Drought Severity Indices (PDSI) with no obvious species‐specific differences. Regional δ 13 C and δ 18 O chronologies share high common variance in year‐to‐year variations. Long‐term variations, however, exhibit differences that may reflect spatial variability in environmental forcings, age trends and/or plant physiological responses to increasing atmospheric CO 2 concentration. Rotated principal component analysis (RPCA) and climate field correlations enable the identification of four sub‐regions in the δ 18 O network ‐ northern and eastern Central Europe, Scandinavia and the western Mediterranean. Regional patterns in the δ 13 C network are less clear and are timescale dependent. Our results indicate that future reconstruction efforts should concentrate on δ 18 O data in the identified European regions.
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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 | 0.002 | 0.005 |
| 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".