marelac (version 2.1.11)

sw_adtgrad: Adiabatic Temperature Gradient in Seawater

Description

Computes the adiabatic temperature gradient in seawater, using the UNESCO 1983 polynomial.

Also known as the adiabatic lapse rate, the change of temperature per unit pressure for an adiabatic change of pressure of an element of seawater. It is assumed that no heat or salt is exchanged with the surroundings.

Usage

sw_adtgrad(S = 35, t = 25, p = P-1.013253, P = 1.013253 )

Value

adiabatic temperature gradient, in dg K / bar

Arguments

S

Practical salinity (-),

t

Temperature, \(^\circ\)C

p

gauge or applied pressure, pressure referenced against the local atmospheric pressure, bar

P

true pressure, bar

Author

Karline Soetaert <[e-mail]>

References

Fofonoff NP and Millard RC Jr, 1983. Algorithms for computation of fundamental properties of seawater. UNESCO technical papers in marine science, 44, 53 pp.
http://unesdoc.unesco.org/images/0005/000598/059832EB.pdf

See Also

sw_alpha, sw_beta, sw_comp, sw_conserv, sw_cp, sw_dens, sw_depth, sw_enthalpy, sw_entropy, sw_gibbs, sw_kappa, sw_kappa_t, sw_sfac, sw_svel, sw_tfreeze, sw_tpot

Examples

sw_adtgrad(t = 40, S = 40, p = 1000)  #3.255976e-4

## Check values
sw_adtgrad(S = 25, t = 10, p = 0)    # 0.1002e-3
sw_adtgrad(S = 25, t = 10, p = 100)  # 0.1135e-3
sw_adtgrad(S = 25, t = 10, p = 1000) # 0.2069e-3

sw_adtgrad(S = 25, t = 30, p = 0)    # 0.2417e-3
sw_adtgrad(S = 40, t = 30, p = 0)    # 0.2510e-3
sw_adtgrad(S = 40, t = 0,  p = 100)  # 0.0630e-3