Mixed Layer Depth Density Criterion
Locate the first density-increase crossing below an interpolated reference depth; deeper inversions do not change the first crossing, and absent crossings are not replaced by profile bottom.
Description
Density-defined mixed-layer depth is the first increase crossing below a reference depth.
Density-defined mixed-layer depth is the first increase crossing below a reference depth. Deeper inversions do not replace that first crossing.
Locate the first density-increase crossing below an interpolated reference depth; deeper inversions do not change the first crossing, and absent crossings are not replaced by profile bottom.
When to use Mixed Layer Depth Density Criterion
Use this tool to locate the first density-increase crossing below an interpolated reference depth; deeper inversions do not change the first crossing, and absent crossings are not replaced by profile bottom.
Gather the water, wave, current or profile observations and any supplied calibration constants. Confirm units and the stated coordinate and pressure conventions.
How to use Mixed Layer Depth Density Criterion and understand its results
- Gather the water, wave, current or profile observations and any supplied calibration constants. Confirm units and the stated coordinate and pressure conventions.
- Enter depthsM, densitiesKgPerM3, referenceDepthM, densityIncreaseCriterionKgPerM3 using the field table and calculation rules, then run the tool.
- Read referenceDensityKgPerM3, mixedLayerCriterionDepthM. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| depthsM | Depths m | list of number | Required |
| densitiesKgPerM3 | Densities kg per m3 | list of number | Required |
| referenceDepthM | Reference depth m | number | Required |
| densityIncreaseCriterionKgPerM3 | Density increase criterion kg per m3 | number | Required |
Use increasing nonnegative depths and positive aligned densities, with reference inside the profile. Interpolate its density, scan downward and interpolate the first target crossing. An absent crossing returns a censored-input error.1
target density = interpolated reference density + positive increase criterion Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| referenceDensityKgPerM3 | Reference density kg per m3 | number |
| mixedLayerCriterionDepthM | Mixed layer criterion depth m | number |
{
"input": {
"depthsM": [
0,
10,
20
],
"densitiesKgPerM3": [
1000,
1001,
1003
],
"referenceDepthM": 5,
"densityIncreaseCriterionKgPerM3": 1
},
"output": {
"referenceDensityKgPerM3": 1000.5,
"mixedLayerCriterionDepthM": 12.5
}
}Limitations and assumptions
The profile bottom is not substituted for missing MLD, and the criterion is caller-chosen.
Numbers and computed results must be finite; overflow produces an error. Numeric lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use TS Diagram Water Mass Classifier: Screen TS samples against caller rectangular water-mass bands, preserving overlaps and unmatched states; no geographic water-mass reference database or forced single identity. For a complementary task, use Thermal Wind Vertical Shear: Integrate signed thermal-wind top-minus-bottom shear from measured horizontal density-gradient profiles on positive-down depths; no absolute reference current or mapped coordinate gradients are inferred.
References
-
Mixed Layer Depth Density Criterion — tool.io
Similar or alternative tools
- TS Diagram Water Mass Classifier
Screen TS samples against caller rectangular water-mass bands, preserving overlaps and unmatched states; no geographic water-mass reference database or forced single identity.
- Thermal Wind Vertical Shear
Integrate signed thermal-wind top-minus-bottom shear from measured horizontal density-gradient profiles on positive-down depths; no absolute reference current or mapped coordinate gradients are inferred.