sw.alpha {oce} | R Documentation |
Compute alpha, the seawater thermal expansion coefficient, as the product of alpha/beta and beta, each calculated from McDougall's (1987) algorithm.
a <- sw.alpha(ctd, is.theta=FALSE) a <- sw.alpha(S, t=NULL, p=NULL, is.theta=FALSE)
ctd |
an object of class "ctd ". |
S |
salinity [PSU] |
t |
in-situ temperature [degC] |
is.theta |
Set TRUE if t is theta or FALSE if t is in-situ |
In the first form, the argument is a ctd
object, from
which the salinity, temperature and pressure values are extracted and
used to for the calculation. Note the use of potential temperature,
not temperature.
Value in 1/degC.
Dan Kelley
McDougall, T.J. 1987. "Neutral Surfaces" Journal of Physical Oceanography vol 17 pages 1950-1964
# 2.5060e-4 (inferred from p1964 of McDougall 1987) a <- sw.alpha(40, 10, 4000)