marelac: gas transfer

## =============================================================
## gas transfer velocity
## implemented by Karline Soetaert
## =============================================================
require(marelac)

wind.seq <- 0:15
plot(wind.seq, gas_transfer(u10 = wind.seq, species = "O2"), 
 type = "l", lwd = 2, xlab = "u10,m/s", ylab = "m/s",
 main = "O2 gas transfer velocity", ylim = c(0, 3e-4))
lines(wind.seq, gas_transfer(u10 = wind.seq, species = "O2", method = "Nightingale"),
 lwd = 2, lty = 2)
lines(wind.seq, gas_transfer(u10 = wind.seq, species = "O2", method = "Wanninkhof1"),
 lwd = 2, lty = 3)
lines(wind.seq, gas_transfer(u10 = wind.seq, 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"))