Electrical conductivity data are converted to salinity using the Practical Salinity Scale and an extension for salinities below 2.
ec2pss(ec, t, p = 0)conductivity, mS/cm
temperature, Celsius
gauge pressure, decibar
ec2pss and R2pss both return salinity values on the
Practical Salinity Scale.
ec2pss converts electrical conductivity data to salinity using the
Practical Salinity Scale 1978 in the range of 2-42 (Fofonoff and Millard
1983). Salinities below 2 are calculated using the extension of the
Practical Salinity Scale (Hill et al. 1986).
R2pss is the same function, except that conductivity ratios rather
than conductivities are used as input.
Input pressures are not absolute pressures but rather gauge pressures. Gauge pressures are measured relative to 1 standard atmosphere, so the gauge pressure at the surface is 0.
Fofonoff N.P. and Millard Jr R.C. (1983) Algorithms for Computation of Fundamental Properties of Seawater. UNESCO Technical Papers in Marine Science 44. UNESCO, Paris, 53 p.
Hill K.D., Dauphinee T.M. and Woods D.J. (1986) The extension of the Practical Salinity Scale 1978 to low salinities. IEEE Journal of Oceanic Engineering 11, 109-112.
# Check values from Fofonoff and Millard (1983):
R = c(1, 1.2, 0.65)
t = c(15, 20, 5)
p = c(0, 2000, 1500)
R2pss(R, t, p) # 35.000 37.246 27.995
#> [1] 35.00000 37.24563 27.99535
# Repeat calculation with equivalent conductivity values by setting
# ec <- R * C(35, 15, 0):
ec = c(1, 1.2, 0.65) * 42.9140
ec2pss(ec, t, p) # same results
#> [1] 35.00000 37.24563 27.99535