sw.sigma {oce} | R Documentation |
Compute sigma, the in-situ density of seawater, minus 1000 kg/m^3.
sw.sigma(S, t=NULL, p=NULL)
S |
either salinity [PSU] (in which case t and p
must be provided) or a ctd object (in which case
S , t and p are determined from the object, and
must not be provided in the argument list). |
t |
in-situ temperature [degC] |
p |
pressure [dbar] |
If the first argument is a ctd
object, then salinity,
temperature and pressure values are extracted from it, and used for
the calculation.
Definition: rho(S,t,p) - 1000 kg/m^3.
In-situ density anomaly [kg/m^3].
Dan Kelley
Fofonoff, P. and R. C. Millard Jr, 1983. Algorithms for computation of fundamental properties of seawater. Unesco Technical Papers in Marine Science, 44, 53 pp
Gill, A.E., 1982. Atmosphere-ocean Dynamics, Academic Press, New York, 662 pp.
Related density routines include: sw.rho
to
calculate in-situ density, sw.sigma.t
to calculate an
archaic quantity found in old textbooks, and
sw.sigma.theta
to calculate potential density anomaly
relative to the surface pressure. If you are thinking of using
sw.sigma
, you probably want sw.sigma.theta
.
sig <- sw.sigma(35, 13, 1000) # 30.818