A Proxy Record of Drought Severity for the Southwestern Canadian Plains
Bibliographic record
Abstract
This paper examines the statistical relationships between Palmer Drought Severity Index (PDSI) data from the southwestern Canadian plains and tree-ring index chronologies from nearby sites. Standardized tree-ring widths from white spruce (Picea glauca) from the Cypress Hills (Alberta and Saskatchewan) and from lodgepole pine (Pinus contorta) from the Bears Paw Mountains (Montana) account for 47% and 39% of the variance in regional July PDSI. The corresponding regressions are the basis for the first reconstructions of PDSI for the Canadian plains. This proxy PDSI record extends from 1597 and demonstrates that, although 1937 was the worst single drought year, the 20th century lacked the prolonged droughts of the 18th and 19th centuries, when decades of July PDSI were consistently below zero. Clusters of drought years in the 1690s, 1720s, 1750s–60s, 1790s–1800s, 1820s, 1850s–60s and 1890s, support the notion of a 20- to 25-year drought cycle for the northern Great Plains. These prolonged droughts lower the resistance of ecosystems and soil landscapes to disturbance from hydroclimatic events, such that thresholds of landscape change are exceeded and the recovery of natural systems can take decades or centuries. These droughts also seriously affect the soil and water resources that support dryland agriculture.
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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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.002 | 0.001 |
| 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".