Northern Hemisphere geography of ice‐covered rivers
Bibliographic record
Abstract
Abstract Although river ice is a major component of the cryosphere and is particularly important to many river processes, including extreme events, its full geographical coverage has never been documented. Recognizing that the freeze‐up and break‐up of river ice is closely linked to the timing of 0 °C air temperatures, this study analyses the spatial extent of river networks relative to the location of three 0 °C isotherm periods. These were defined to represent a suite of ice‐affected conditions that would be experienced for 6, 3 or 0·5 month periods, the briefest interval possibly leading only to a very thin and transient ice cover or simply border/frazil ice formation. Four different GIS databases were used to represent the river networks. The percentages of the total Northern Hemisphere land mass (average river network) influenced by cold temperatures conducive to ice formation were 52, 45 and 25 (56, 47 and 28), respectively. The related southern position of the isotherms ranged from 33°N, 35°N and 50°N in central North America to a nearly consistent 27°N for Eurasia, reflecting the influence of the high‐elevation central plateau region. Also identified are the lengths of major rivers that fall within the three 0 °C isotherm boundaries. Included are some of the world's largest rivers including the Lena, Mackenzie, Ob, Yellow, Yukon and Yenisey rivers, although their percentage of ice‐affected coverage varied for the three isotherm periods from a consistent 100% for the Lena and Yukon rivers to as little as 23% at the 6‐month interval for the Yellow River. Copyright © 2009 Her Majesty the Queen in right of Canada. Published by John Wiley & Sons, Ltd.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 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) | 0.001 | 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".