| swThermalConductivity {oce} | R Documentation |
Compute seawater thermal conductivity, in W/(m*degC)
swThermalConductivity(salinity, temperature = NULL, pressure = NULL)
salinity |
salinity (PSU), or a |
temperature |
in-situ temperature (degC), defined
on the ITS-90 scale; see “Temperature units” in the documentation for
|
pressure |
pressure (dbar) |
Caldwell's (1974) detailed formulation is used. To be specific, his equation 6 to calculate K, and his two sentences above that equation are used to infer this to be K(0,T,S) in his notation of equation 7. Then, application of his equations 7 and 8 is straightforward. He states an accuracy for this method of 0.3 percent. (See the check against his Table 1 in the “Examples”.)
Conductivity of seawater in W/(m*degC). To calculate thermal diffusivity in m^2/s, divide by the product of density and specific heat, as in the example.
Dan Kelley
Caldwell, Douglas R., 1974. Thermal conductivity of seawater, Deep-sea Research, 21, 131-137.
Other functions that calculate seawater properties:
T68fromT90(),
T90fromT48(),
T90fromT68(),
swAbsoluteSalinity(),
swAlphaOverBeta(),
swAlpha(),
swBeta(),
swCSTp(),
swConservativeTemperature(),
swDepth(),
swDynamicHeight(),
swLapseRate(),
swN2(),
swPressure(),
swRho(),
swRrho(),
swSCTp(),
swSTrho(),
swSigma0(),
swSigma1(),
swSigma2(),
swSigma3(),
swSigma4(),
swSigmaTheta(),
swSigmaT(),
swSigma(),
swSoundAbsorption(),
swSoundSpeed(),
swSpecificHeat(),
swSpice(),
swTFreeze(),
swTSrho(),
swTheta(),
swViscosity(),
swZ()
library(oce) # Values in m^2/s, a unit that is often used instead of W/(m*degC). swThermalConductivity(35, 10, 100) / (swRho(35,10,100) * swSpecificHeat(35,10,100)) # ocean swThermalConductivity(0, 20, 0) / (swRho(0, 20, 0) * swSpecificHeat(0, 20, 0)) # lab # Caldwell Table 1 gives 1478e-6 cal/(cm*sec*degC) at 31.5 o/oo, 10degC, 1kbar joulePerCalorie <- 4.18400 cmPerM <- 100 swThermalConductivity(31.5,10,1000) / joulePerCalorie / cmPerM