Practical Salinity PSS78 From CTD Converter

UNESCO PSS78 conductivityR=C(S, t, p)/C(35,15,0), pressure correction,2≤S≤42,−2≤IPTS68t≤35, no low-salinity or conductivity-units ambiguity. 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

Practical Salinity on PSS-78 is calculated from a conductivity ratio corrected for temperature and pressure.

Practical Salinity on PSS-78 is calculated from a conductivity ratio corrected for temperature and pressure.^{[1, 2]}

Its ratio reference and IPTS-68 temperature scale must match the CTD data.

When to use Practical Salinity PSS78 From CTD Converter

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 Practical Salinity PSS78 From CTD Converter and understand its results

Match the observation interval, units, datum, coordinate signs and model regime.
Enter observedConductivityRatioToC35150, temperatureIpts68C, pressureDbar, using the field meanings and rules below, then run the tool.
Read practicalSalinityPss78. 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
observedConductivityRatioToC35150	Observed conductivity ratio to c35150	number	Required
temperatureIpts68C	Temperature ipts68 c	number	Required
pressureDbar	Pressure dbar	number	Required

Require positive R=C(S,t,p)/C(35,15,0), IPTS-68 temperature −2..35 °C and gauge pressure 0..10000 dbar. Calculate the temperature reference polynomial rt and pressure factor rp; require R/(rt×rp)>0. Evaluate the two six-coefficient PSS-78 polynomials in sqrt(R/(rt×rp)), combining them with (t−15)/(1+.0162(t−15)). Reject resulting salinity outside 2..42. No low-salinity extension is implemented.

S=A(x)+[(t−15)/(1+.0162(t−15))]B(x); x=√[R/(rt rp)]

Use the matching field units and the exact boundary, ordering and reference rules above.

Output field	Meaning	Value type
practicalSalinityPss78	Practical salinity pss78	number

json

{
  "input": {
    "observedConductivityRatioToC35150": 1,
    "temperatureIpts68C": 15,
    "pressureDbar": 0
  },
  "output": {
    "practicalSalinityPss78": 34.99999992412809
  }
}

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 Potential Density Sigma Theta Calculator: Potential density evaluates a parcel at its potential temperature and a chosen reference pressure.

References

Practical Salinity PSS78 From CTD Converter — tool.io
Algorithms for the computation of fundamental properties of seawater — UNESCO

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.
Potential Density Sigma Theta Calculator
Potential density evaluates a parcel at its potential temperature and a chosen reference pressure.