Converts from absolute to practical salinity based on depth and geographic location.
Usage
sa2sp_geo(SA, P=0, long=1.e20, lat=1.e20)
Value
SP
Practical salinity (psu)
Arguments
SA
Absolute salinity in g/kg
P
Sea water pressure in dbar
long
Longitude in decimal degrees [ 0 ... +360 ] or [ -180 ... +180 ]
lat
Latitude in decimal degrees [-90 ... 90]
Author
Jean-Marie Epitalon
Details
This function is almost an alias of subroutine gsw_SP_from_SA from gsw package on which it relies. The only difference is in that depth and location are optional. If location is not given, or incomplete (either longitude or latitude missing), an arbitrary location is chosen: the mid equatorial atlantic ocean. Note that this implies an error on computed SA ranging from 0 up to 0.02 g/kg.
References
McDougall T. J., Jackett D. R., Millero F. J., Pawlowicz R. and Barker P. M., 2012. A global algorithm for estimating Absolute Salinity. Ocean Science8, 1123-1134.
Pawlowicz R., 2013. What every oceanographer needs to know about TEOS-10 (The TEOS-10 Primer). http://www.teos-10.org/
# Calculate the practical salinity of a sample whose absolute Salinity is 35,# depth is 10 dbar and location is 188 degrees East and 4 degrees North. SP <- sa2sp_geo(35, 10, 188, 4)