Synoptic-Scale Zonal Available Potential Energy Increases in the Northern Hemisphere
Bibliographic record
Abstract
Abstract Available potential energy (APE), a measure of the energy available for conversion to kinetic energy, has been previously applied to examine changes in baroclinic instability and seasonal changes in the general circulation. Here, pathways in which the troposphere can build the reservoir of zonal available potential energy AZ on synoptic (3–10 day) time scales are explored. A climatology of AZ and its generation GZ and conversion terms are calculated from the National Centers for Environmental Prediction–Department of Energy Reanalysis 2 dataset from 1979 to 2011 for 20°–85°N. A standardized anomaly-based identification technique identifies 183 AZ buildup events, which are grouped into two event types based upon their final AZ standardized anomaly (σ) value: 1) buildup anomalous (BA) events, which exceed 1.5σ, and 2) buildup neutral (BN) events, which do not exceed 1.5σ. Increases in GZ and reductions in baroclinic conversion CA, source and sink terms for AZ, are shown to equally contribute toward increasing AZ in most seasons. A synoptic analysis of composited mass fields for winter BA events (n = 18 events) and winter BN events (n = 28 events) is performed to identify contributions to anomalously low CA and high GZ. A process of high-latitude cooling near 160°E–120°W is found for both composite event types. The cooling processes are characterized by a period of poleward moisture flux and ascent followed by an isolation of the Arctic from the midlatitude flow, resulting in enhanced GZ. Negative anomalies in CA are also diagnosed, which generally occur in regions with northerly dynamic tropopause wind anomalies and neutral to positive thickness anomalies.
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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 | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 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 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".