marelac (version 2.1.9)

gas_transfer: The Gas Transfer Coefficient in m/sec

Description

The gas transfer coefficient, in \(m s^{-1}\), for certain gases in seawater (S = 35).

Usage

gas_transfer(t = 25, u10 = 1, species = c("He", "Ne", "N2", "O2", "Ar",
        "Kr", "Rn", "CH4","CO2", "N2O", "CCl2F2", "CCL3F",
        "SF6", "CCl4"),
  method = c("Liss", "Nightingale", "Wanninkhof1", "Wanninkhof2"),
  Schmidt = gas_schmidt(t = t, species = species))

Arguments

t

Temperature in \(^\circ\)C,

u10

wind speed, in m/sec at a nominal height of 10 m above sea level,

species

character vector with gasses whose gas transfer coefficient should be estimated.

method

one of "Liss", for Liss and Merlivat, 1986; "Nightingale", for Nightingale et al., 2000; "Wanninkhof1", for Wanninkhof 1992, or "Wanninkhof2" for Wanninkhof and McGills 1999.

Schmidt

the Schmidt number, when given this overrules the arguments gas and t.

Value

The gas transfer velocity, for seawater, in \(m s^{-1}\).

References

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

Liss PS and Merlivat L, 1986. Air-sea gas exchange rates: introduction and synthesis. In: the role of air-sea exchange in Geochemical cycling, edited by P. Buat-Menard, pp 113-127. D. Reidel, Dordrecht, the Netherlands.

Nightingale et al., 2000. In situ evaluation of air-sea gas exchange prameterizations using novel conservative and volatile tracers. Global biogeochemical cycles 14, 373-387.

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

Wanninkhof R and McGillis W, 1999. A cubic relationshp between air-sea CO2 exchange and wind speed. Geophys. Res. Lett. 26, 1889-1892.

See Also

gas_O2sat,gas_satconc, gas_schmidt,gas_solubility, atmComp, vapor

Examples

# NOT RUN {
<!-- %% Check measurement units! -->
# }
# NOT RUN {
<!-- %% - hre it is m/s but in Wanninkhof it is cm/hr -->
# }
# NOT RUN {
<!-- %% - Note also that Wanninkhof uses CO2 and not O2, I suggest to change this -->
# }
# NOT RUN {
useq <- 0:15
plot(useq, gas_transfer(u10 = useq, species = "O2"), type = "l", lwd = 2, xlab = "u10, m/s",
     ylab = "m/s", main = "O2 gas transfer velocity", , ylim = c(0, 0.0003))
lines(useq, gas_transfer(u10 = useq, species = "O2", method = "Nightingale"), lwd = 2, lty = 2)
lines(useq, gas_transfer(u10 = useq, species = "O2", method = "Wanninkhof1"), lwd = 2, lty = 3)
lines(useq, gas_transfer(u10 = useq, species = "O2", method = "Wanninkhof2"), lwd = 2, lty = 4)

legend("topleft", lty = 1:4, lwd = 2,
  legend = c("Liss and Merlivat 1986", "Nightingale et al. 2000",
  "Wanninkhof 1992", "Wanninkhof and McGills 1999"))
# }