Instability of Abyssal Currents in a Continuously Stratified Ocean with Bottom Topography
Bibliographic record
Abstract
A theory is developed for the baroclinic destabilization of density-driven abyssal flows over topography in a rotating environment.The dominant instability mechanism being studied is the release of available potential energy caused by gradual downhill slumping of the abyssal current.The present model assumes a two-layer configuration and allows for intersections of the interface with the bottom (i.e., true fronts), as well as continuous stratification in the ambient fluid.The linear instability problem in a channel for a current with parabolic cross section is solved, and the perturbation growth rate and most unstable wavenumber are both shown to increase with current thickness.A similar trend is evident as the stratification number is increased or the current width is decreased.The instability manifests itself in the overlying ocean as an amplifying topographic Rossby wave.Alternating positive/negative pressure anomalies in the upper layer are accompanied by a wavelike deformation of the abyssal current that is most pronounced on the downslope side.Upper-layer vortical features have a distinct vertically tapered shape and are to be interpreted as bottom-intensified eddies.Long-term evolution of the flow is elucidated in a series of simulations employing the fully nonlinear governing equations.It is found that, even though the linear instability calculation relates to a periodic current, the instability characteristics are still valid to a good approximation for the case of a source flow.The abyssal current breaks up into a series of plumes that penetrate downslope into the deeper ocean, producing strong current fluctuations not unlike those observed in Denmark Strait overflow water.Furthermore, introduction of more realistic topography into the numerical simulation leads to the development of coherent baroclinic vortex pairs whose upper-layer component is strongly cyclonic.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| 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".