Light attenuation experiments on double diffusive plumes and fountains
Bibliographic record
Abstract
By adapting the method of light attenuation to the study of axisymmetric disturbances, we examine the structure of forced plumes and fountains whose buoyancy is set by salinity and/or temperature differences between the turbulent flow and the otherwise stationary ambient. The attenuation measurements are used to infer the statistically steady-state density as a function of radius and height. These compare well with in situ measurements of density taken from a conductivity-temperature probe that repeatedly traversed the centreline of the plume. The theory for forced plumes also agrees well with the centreline density profile. The radial structure of plumes and fountains near the source is found to correspond well to a Gaussian profile, although the standard deviation is found to increase moderately faster with height than spreading rates reported in the existing literature. This is attributed in part to averaging biases resulting from light attenuating through transient eddies. In most experiments, hot and salty fountains reached a steady state height consistent with existing semi-empirical theories for fountains with just one diffusive component. However, if the density of the hot and salty fluid near the source is close to, but moderately larger than, that of the ambient, over time, the fountain is observed to increase progressively in height. This occurs presumably as a consequence of heat diffusion at the top of the fountain making the ambient above it increasingly buoyant relative to the negative buoyancy associated with less diffusive salt.
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 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) | 0.000 | 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".