marelac (version 2.0)

gas_transfer: The Gas Transfer Coefficient in cm/hr

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 exchnage prameterizations using novel conservatie 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 ari-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

useq <- 0:15
plot(useq, gas_transfer(u10 = useq), type = "l", lwd = 2, xlab = "u10, m/s",
     ylab = "m/s", main = "O2 gas transfer velocity", ylim = c(0,75))
lines(useq, gas_transfer(u10 = useq, method = "Nightingale"), lwd = 2, lty = 2)
lines(useq, gas_transfer(u10 = useq, method = "Wanninkhof1"), lwd = 2, lty = 3)
lines(useq, gas_transfer(u10 = useq, 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"))