Climate and glacier mass balance trends from <scp>ad</scp> 1780 to present in the Columbia Mountains, British Columbia, Canada
Bibliographic record
Abstract
Climate and glacier mass balance trends from 1780 to present within the Columbia Mountains, British Columbia, Canada, were investigated using tree-ring data. Annually resolved ring width, maximum density and maximum cell wall thickness chronologies were constructed from increment core samples of Engelmann spruce ( Picea engelmannii), mountain hemlock ( Tsuga mertensiana) and subalpine fir ( Abies lasiocarpa) trees collected in Glacier and Revelstoke national parks. Proxy records of maximum June–August temperature, August precipitation and February snowpack provide insight into long-term seasonal climate changes. The intervals 1790–1810, 1850–1870 and 1930–1950 were characterized by warm summer temperatures. While overall August precipitation totals decrease over the period of record, the late 1700s, 1805–1835, the 1880s, 1960–1975 and the mid 1980s were notably wetter. February snowpacks have generally decreased in depth since 1873. The reconstructed winter, summer and net mass balance records indicate that glacier cover in the Columbia Mountains has varied primarily in response to decreased snowfall since the mid 1700s. Intervals of terminus advance and retreat were shown to reflect glaciological responses to relatively short-duration variations in summer temperature and winter snowfall. The rate of cumulative mass balance decline within the last 30 years exceeds that observed at any time over the last 250 years.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.003 | 0.005 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| 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".