Hydroclimatic Change in Southern Manitoba Since A.D. 1409 Inferred from Tree Rings
Bibliographic record
Abstract
Abstract A record of estimated annual (prior August to current July) precipitation derived from a regional bur oak ( Quercus macrocarpa Michx.) tree-ring chronology indicates that southern Manitoba's hydroclimate has been relatively stable over the last 200 yr. Although this stability was interrupted briefly by pronounced wet intervals in the late A.D. 1820s and 1850s, hydroclimatic conditions since permanent Euro-Canadian settlement were much less variable and persistent than those prior to A.D. 1790. The reconstruction indicates that the Red River basin experienced extremely dry conditions between A.D. 1670 and 1775, with below-normal precipitation occurring approximately 2 years out of 3. Annual precipitation was estimated at more than two standard deviations below the mean during A.D. 1477, 1485, 1556, 1595, 1612, 1644, 1661, 1743, 1900, and 1980. Comparisons with limnological records from North Dakota and Minnesota suggest that multidecadal fluctuations in regional hydroclimate have been remarkably coherent across the northeastern Great Plains during the last 600 yr. However, individual dry years in the Red River basin were usually associated with larger scale drought across much of the North American interior.
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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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".