swSigma {oce} | R Documentation |
Compute sigma, the density of seawater, minus 1000 kg/m^3.
swSigma(salinity, temperature=NULL, pressure=NULL, longitude=300, latitude=30, eos=getOption("oceEOS", default="gsw"))
salinity |
either practial salinity or an |
temperature |
in-situ temperature [degC], defined on
the ITS-90 scale; see “Temperature units” in the documentation for
|
pressure |
pressure [dbar]. |
longitude |
longitude of observation (only used if |
latitude |
latitude of observation (only used if |
eos |
name of equation of state to be used, either |
If the first argument is an oce
object, then salinity, etc., are
extracted from it, and used for the calculation instead of any values provided
in the other arguments.
Density anomaly [kg/m^3], defined as swRho
- 1000
kg/m^3.
Dan Kelley
See citations provided in the swRho
documentation.
Related density routines include: swRho
,
swSigmaT
, swSigmaTheta
, swSigma0
,
etc.
library(oce) swSigma(35, 13, 1000, eos="gsw") # 30.82397 swSigma(35, T90fromT68(13), 1000, eos="unesco") # 30.8183