| swRrho {oce} | R Documentation |
Compute density ratio
swRrho(ctd, sense = c("diffusive", "finger"), smoothingLength = 10, df,
eos = getOption("oceEOS", default = "gsw"))
ctd |
an object of class |
sense |
an indication of the sense of double diffusion under study and therefore of the definition of Rrho; see ‘Details’ |
smoothingLength |
ignored if |
df |
if given, this is provided to |
eos |
equation of state, either |
This computes Rrho (density ratio) from a ctd object.
If eos="unesco", this is done by calculating salinity and
potential-temperature derivatives from smoothing splines whose properties
are governed by smoothingLength or df. If
sense="diffusive" the definition is
(beta*dS/dz)/(alpha*d(theta)/dz) and
the reciprocal for "finger".
If eos="gsw", this is done by extracting absolute salinity and
conservative temperature, smoothing with a smoothing spline as in the
"unesco" case, and then calling gsw_Turner_Rsubrho
on these smoothed fields. Since the gsw function works on mid-point
pressures, approx is used to interpolate back to the original
pressures.
If the default arguments are acceptable, ctd[["Rrho"]] may be used
instead of swRrho(ctd).
Density ratio defined in either the "diffusive" or
"finger" sense.
Dan Kelley and Chantelle Layton
Other functions that calculate seawater properties: T68fromT90,
T90fromT48, T90fromT68,
swAbsoluteSalinity,
swAlphaOverBeta, swAlpha,
swBeta, swCSTp,
swConservativeTemperature,
swDepth, swDynamicHeight,
swLapseRate, swN2,
swPressure, swRho,
swSCTp, swSTrho,
swSigma0, swSigma1,
swSigma2, swSigma3,
swSigma4, swSigmaTheta,
swSigmaT, swSigma,
swSoundAbsorption,
swSoundSpeed, swSpecificHeat,
swSpice, swTFreeze,
swTSrho,
swThermalConductivity,
swTheta, swViscosity,
swZ
library(oce)
data(ctd)
u <- swRrho(ctd, eos="unesco")
g <- swRrho(ctd, eos="gsw")
p <- ctd[["p"]]
plot(u, p, ylim=rev(range(p)), type='l', xlab=expression(R[rho]))
lines(g, p, lty=2, col='red')
legend("topright", lty=1:2, legend=c("unesco", "gsw"), col=c("black", "red"))