oce (version 0.9-20)

T68fromT90: Convert from ITS-90 to IPTS-68 temperature

Description

Today's instruments typically record in the ITS-90 scale, but some old datasets will be in the IPTS-68 scale. T90fromT68() converts from the IPTS-68 to the ITS-90 scale, using Saunders' (1990) formula, while T68fromT90() does the reverse. The difference between IPTS-68 and ITS-90 values is typically a few millidegrees (see ‘Examples’), which is seldom visible on a typical temperature profile, but may be of interest in some precise work. Mostly for historical interest, T90fromT48() is provided to convert from the ITS-48 system to ITS-90.

Usage

T68fromT90(temperature)

Arguments

temperature

Vector of temperatures expressed in the ITS-90 scale.

Value

Temperature expressed in the IPTS-68 scale.

References

P. M. Saunders, 1990. The international temperature scale of 1990, ITS-90. WOCE Newsletter, volume 10, September 1990, page 10. (http://www.nodc.noaa.gov/woce/wdiu/wocedocs/newsltr/news10/contents.htm)

See Also

Other functions that calculate seawater properties: 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, swThermalConductivity, swTheta, swViscosity, swZ

Examples

library(oce)
T68 <- seq(3, 20, 1)
T90 <- T90fromT68(T68)
sqrt(mean((T68-T90)^2))