Description
Compare supplied depth and surface irradiance.
Aquatic measurements depend on depth datums, effective sampling area, layer weights and concentration definitions. Secchi pair averages differ from a full optical model, and particulate-by-difference values depend on comparable total/dissolved measurements. A nominal rectangular sampling volume does not establish actual filtered effort or detection.
Compare supplied depth and surface irradiance.
When to use this tool
Use Aquatic Light Depth Ratio when you already have depthIrradiance, surfaceIrradiance and need to compare supplied depth and surface irradiance.
How to use the tool and how it works
- Enter depthIrradiance, surfaceIrradiance. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read remainingLightFraction, attenuationFraction. Use the output convention below.
Require surfaceIrradiance>0 and depthIrradiance>=0; return depth/surface and 1-depth/surface.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| depthIrradiance | Depth Irradiance | Required. Finite number; minimum 0. |
| surfaceIrradiance | Surface Irradiance | Required. Finite number; strictly above 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| remainingLightFraction | Remaining Light Fraction | Required. Finite number. |
| attenuationFraction | 1-depthIrradiance/surfaceIrradiance, accepted even when negative. | Required. Finite number. |
{
"input": {
"depthIrradiance": 20,
"surfaceIrradiance": 100
},
"output": {
"remainingLightFraction": 0.2,
"attenuationFraction": 0.8
}
}Limitations and assumptions
- Values above one and negative attenuation fractions are accepted. Comparable spectral and geometric bases are required; no attenuation coefficient, profile or optical model is fitted.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Review original field and laboratory records with the complete survey or process model. Include calibration, temporal coverage, sampling efficiency and uncertainty when local rates, depth shifts or labels cannot establish the aquatic quantity of interest.
References
Similar or alternative tools
- Secchi Pair Midpoint
Average supplied Secchi disappearance and reappearance depths.
- Water Column Layer Average
Calculate a supplied depth-weighted water-column mean.