sw.depth {oce} | R Documentation |
Compute depth from pressure and latitude.
sw.depth(p, lat=45, degrees=TRUE)
p |
either pressure [dbar], in which case lat must also be
given, or a ctd object, in which case lat will be
inferred from the object. |
lat |
Latitude in degN or radians north of the equator. |
degrees |
Flag indicating whether degrees are used for latitude;
if set to FALSE , radians are used. |
If the first argument is a ctd
object, then the pressure
and latitude are extracted from it, and used to for the calculation.
The information given below is adapted from the fortran code at http://sam.ucsd.edu/sio210/propseawater/ppsw_fortran/ppsw.f, on which this R code was based.
Depth in meters from pressure in decibars using Saunders and Fofonoff's method, with the formula refitted for 1980 equation of state
Check value: depth = 9712.653 m for p=10000 decibars, latitude=30 deg above for standard ocean: t=0 deg. celsuis ; s=35 (ipss-78)
Depth below the ocean surface, in metres.
Dan Kelley
(authors?), 1976, (title?), Deep-Sea Res., 23, 109-111.
d <- sw.depth(10, 45);