Potential Density Sigma Theta Calculator
UNESCO adiabatic potential temperature then EOS80 potential density−1000 at explicit reference; sigma-theta when reference0dbar, not in-situ density or TEOS 10. Caller independently establishes units, regime, calibration and applicability; this does not establish design-code compliance, authenticity, operational safety, treatment efficacy or a validated forecast.
Description
Potential density evaluates a parcel at its potential temperature and a chosen reference pressure.
When to use Potential Density Sigma Theta Calculator
Use this tool to calculate or review the supplied observations under the stated rules. Match the observation interval, units, datum, coordinate signs and model regime.
How to use Potential Density Sigma Theta Calculator and understand its results
- Match the observation interval, units, datum, coordinate signs and model regime.
- Enter observedTemperatureIpts68C, observedPracticalSalinity, observedPressureDbar, callerReferencePressureDbar, using the field meanings and rules below, then run the tool.
- Read potentialTemperatureIpts68C, referencePotentialDensityAnomalyKgM3. Inspect nested result fields where present, and review unknown records separately from known matches.
- Correct any reported input issue and run again. Before using a successful result, check the stated units, signs, reference scope and observation coverage.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| observedTemperatureIpts68C | Observed temperature ipts68 c | number | Required |
| observedPracticalSalinity | Observed practical salinity | number | Required |
| observedPressureDbar | Observed pressure dbar | number | Required |
| callerReferencePressureDbar | Caller reference pressure dbar | number | Required |
First calculate UNESCO potential temperature under the rules described for the potential-temperature tool. Then apply EOS-80 at that temperature, practical salinity and reference pressure, and subtract 1000 kg/m³. The density helper accepts temperature 0..40 °C, salinity 0..42 and pressure 0..10000 dbar; a negative computed potential temperature therefore fails here. EOS-80 evaluates atmospheric density and a salinity/temperature/pressure bulk modulus, converts dbar to bar, and divides by the positive compressibility factor.
σ=ρ_EOS80(θ,S,p_ref)−1000 Use the matching field units and the exact boundary, ordering and reference rules above.
| Output field | Meaning | Value type |
|---|---|---|
| potentialTemperatureIpts68C | Potential temperature ipts68 c | number |
| referencePotentialDensityAnomalyKgM3 | Reference potential density anomaly kg m3 | number |
{
"input": {
"observedTemperatureIpts68C": 0,
"observedPracticalSalinity": 0,
"observedPressureDbar": 0,
"callerReferencePressureDbar": 0
},
"output": {
"potentialTemperatureIpts68C": 0,
"referencePotentialDensityAnomalyKgM3": -0.15740600000003724
}
}Limitations and assumptions
The stated observation or model covers only the supplied record and reference regime. It does not fill missing measurements, supply uncertainty estimates or produce a validated forecast.
Missing required fields, unknown fields, wrong types and violated rules return input issues. Numeric values and outputs must be finite.
Alternative or Complementary methods
For a related step, use Potential Temperature UNESCO Adiabatic Calculator: Potential temperature is the temperature a water parcel would have after an adiabatic move to a reference pressure. For a complementary comparison, use Brunt Vaisala Ocean Stability Calculator: The squared Brunt–Väisälä frequency describes stratification in a matched density profile.
References
Similar or alternative tools
- Potential Temperature UNESCO Adiabatic Calculator
Potential temperature is the temperature a water parcel would have after an adiabatic move to a reference pressure.
- Brunt Vaisala Ocean Stability Calculator
The squared Brunt–Väisälä frequency describes stratification in a matched density profile.