Extracting a paleotemperature record from <i>Picea engelmannii</i> tree-line sites in the central Canadian Rockies
Bibliographic record
Abstract
A new network of 21 Picea engelmannii Parry ex Engelm. ring-width chronologies was developed from tree-line sites in the Canadian Rockies. These chronologies range in length from 297 to 648 years (mean 423 years) and have mean sensitivities between 0.16 and 0.20 (mean 0.18), first-order autocorrelations between 0.73 and 0.88 (mean 0.83), and subsample signal strengths >0.85 for 246-494 years (mean 324 years). Mean intersite correlations (A.D. 1700-1982) for chronologies with expressed population signals >0.85 are 0.46 and 0.63 for standard and residual chronologies, respectively. Standard ring-width chronologies are, in general, positively correlated with summer temperatures and negatively correlated with spring and previous summer temperatures. A regional June-September temperature reconstruction for the Banff-Jasper region (BJR; A.D. 1715-1982) was developed using multiple regression of three significant principal components from 14 standard ring-width chronologies. The first principal component contains 55% of the total chronology variance. The model reconstructs 38% of summer temperature variance during the calibration period (1888-1982). The BJR is the first regional temperature reconstruction for this area based on ring-width data from a network of sites. The reconstructed temperature patterns are broadly similar to other regional estimates of past temperatures. Above-average summer temperatures occurred in the mid-20th century and the late 1700s - early 1800s. Most of the 19th century was unusually cold, with the coldest conditions in the late 19th century. Detailed differences between BJR and previously developed reconstructions lie well within 2σ confidence limits and may reflect differences in tree species, modelling techniques, spatial coverage, and the seasonal temperature parameter reconstructed.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 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 | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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 teacher head, 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".