gsw 3.0.3

Gibbs SeaWater Oceanographic Package of TEOS-10

(This python module is incomplete and should be used with caution!)

Python implementation of the Thermodynamic Equation Of Seawater - 2010 (TEOS-10)

This module is an python alternative to the gsw MatlabTM toolbox. The table below shows some function names in the gibbs library and the corresponding function names in the seawater library.

TEOS-10 vs. EOS-80

Variable	SeaWater (EOS 80)	Gibbs SeaWater (GSW TEOS 10)
Absolute Salinity	NA	gsw.SA_from_SP(SP,p,long,lat)
Conservative Temperature	NA	gsw.CT_from_t(SA,t,p)
density (i.e. in situ density)	sw.dens(SP,t,p)	gsw.rho_CT(SA,CT,p), or gsw.rho(SA,t,p)
potential density	sw.pden(SP,t,p,pr)	gsw.rho_CT(SA,CT,pr)
potential temperature	sw.ptmp(SP,t,p,pr)	gsw.pt_from_t(SA,t,p,pr)
\(\sigma_0\), using \(\theta_o\) = sw.ptmp(SP,t,p,0)	sw.dens(SP, \(\theta_o\), 0) -1000 kg m\(^{-3}\)	gsw.sigma0_CT(SA,CT)
\(\sigma_2\), using \(\theta_2\) = sw.ptmp(SP,t,p,2000)	sw.dens(SP,\(\theta_2\), 2000) -1000 kg m\(^{-3}\)	gsw.sigma2_CT(SA,CT)
\(\sigma_4\), using \(\theta_4\) = sw.ptmp(SP,t,p,2000)	sw.dens(SP,\(\theta_4\), 4000) -1000 kg m\(^{-3}\)	gsw.sigma2_CT(SA,CT)
specific volume anomaly	sw.svan(SP,t,p)	gsw.specvol_anom_CT(SA,CT,p)
dynamic height anomaly	-sw.gpan(SP,t,p)	gsw.geo_strf_dyn_height(SA,CT,p,delta_p,interp_style)
geostrophic velocity	sw.gvel(ga,lat,long)	gsw.geostrophic_velocity(geo_str,long,lat,p)
N\(^2\)	sw.bfrq(SP,t,p,lat)	gsw.Nsquared(SA,CT,p,lat)
pressure from height (SW uses depth, not height)	sw.pres(-z,lat)	gsw.p_from_z(z,lat)
height from pressure (SW outputs depth, not height)	z = -sw.dpth(p,lat)	gsw.z_from_p(p,lat)
in situ temperature from pt	sw.temp(SP,pt,p,pr)	gsw.pt_from_t(SA,pt,pr,p)
sound speed	sw.svel(SP,t,p)	gsw.sound_speed(SA,t,p)
isobaric heat capacity	sw.cp(SP,t,p)	gsw.cp(SA,t,p)
adiabatic lapse rate*	sw.adtg(SP,t,p)	gsw.adiabatic_lapse_rate(SA,t,p)
SP from cndr, (PSS 78)	sw.salt(cndr,t,p)	gsw.SP_from_cndr(cndr,t,p)
cndr from SP, (PSS 78)	sw.cndr(SP,t,p)	gsw.cndr_from_SP(SP,t,p)
distance	sw.dist(lat,long,units)	gsw.distance(long,lat,p)
gravitational acceleration	sw.g(lat,z)	gsw.grav(lat,p)
Coriolis parameter	sw.f(lat)	gsw.f(lat)

Note that the SW and GSW functions output the adiabatic lapse rate in different units, being K (dbar):math:^{-1} and K Pa\(^{-1}\) respectively.

Authors

• Bjørn Ådlandsvik

• Eric Firing

• Filipe Fernandes

Thanks

• Bjørn Ådlandsvik - Testing unit and several bug fixes.

• Eric Firing - Support for masked arrays, re-write of deltaSA.

• Trevor J. McDougall (and all of SCOR/IAPSO WG127) for making available the Matlab version of this software.

Acknowledgments

• SCOR/IAPSO WG127 for the original MatlabTM code.

Caveats

• This python module is incomplete and should be used with caution.

• The database used in _delta_SA comes from the MatlabTM gsw version.

Changelog

Version 3.0.3

• Fixed NumPy 1.8.1 indexing bug.

Version 3.0

• New repository with TEOS-10 code (version 3 only).