marelac (version 2.0)

gas_schmidt: The Schmidt Number for Gases in Seawater

Description

The Schmidt number as a function of temperature (0-30dgC) and for a salinity of 35.

$Sc = v/D = Mu/(rho+D)$

where v is the kinematic viscosity of the water and D is the mass diffusivity, rho is density and mu is the viscosity.

Schmidt numbers are used to estimate the gas transfer velocity.

Usage

gas_schmidt(t = 25, species = c("He", "Ne", "N2", "O2", "Ar",
        "Kr", "Rn", "CH4","CO2", "N2O", "CCl2F2", "CCL3F",
        "SF6", "CCl4"))

Arguments

t

Temperature in $^\circ$C,

species

character vector with gasses whose schmidt number should be estimated.

Value

• The Schmidt number, a dimensionless quantity.

References

Sarmiento JL and Gruber N, 2006. Ocean Biogeochemical Dynamics. Princeton University Press, Princeton. p 85.

who cite:

Wanninkhof R, 1992. Relationship between wind speed and gas exchange over the ocean. Journ. Geophys. Res. 97, 7373-7383.

except for $O_2$:

Keeling et al., 1998. Seasonal variation in the atmospheric O2/N2 ratio in relation to the kinetics of air-sea gas exchange. Global Biogeochemical Cycles 12, 141-164.

CFC-11 ($CCl_2F_2$), and CFC-12 ($CCl_3F$):

Zheng et al., 1998. Measurements of the diffusion coefficients of CF-11 and CF-12 in pure water and seawater. Journ. Geophys. Res. 103, 1375-1379.

and $CCl_4$ (Wanninkhof, pers.comm).

See Also

gas_O2sat, gas_satconc, gas_solubility, gas_transfer, atmComp, vapor

Examples

gas_schmidt(species = "CO2", t=20) # about660