gas_O2sat {marelac}

Saturation Concentration of Oxygen in Water

Description

Empirical formulae that can be used to compute saturation concentration of oxygen in water in mg/L

Usage

gas_O2sat(S = 35, t = 25, masl = 0, method = c("Weiss", "APHA", "Paul"))

Arguments

S

salinity (dimensionless, for method "Weiss" only),

t

Temperature in ^\circC,

masl

height above sea level (in m, for method "Paul" only),

method

formula to be used, see references for correct application.

Details

Method APHA is the standard formula in Limnology, method Weiss the standard formula in marine sciences. The method after Paul is a simple formula fitted on available tables. To avoid confusion between the arguments (S, t, masl) it is advisable to use named arguments in general, e.g. O2sat(t = 4).

Value

Vector with oxygen saturation concentration in mg L^{-1}.

References

American Public Health Association, Inc. (1985): Standard Methods for the Examination of Water and Wastewater. 18th edition, 1992.

Benson BB and Krause D, 1980. The concentration and isotopic fractionation of gases dissolved in freshwater in equilibrium with the atmosphere. I. Oxygen. Limnology and Oceanography 25, 662-671.

Brown LC and Barnwell TO Jr, 1987. The Enhanced Stream Water Quality Models QUAL2E and QUAL2E-UNCAS: Documentation and User Manual. U.S. Environmental Protection Agency, Athens, Georgia. EPA/600/3-87/007, p. 41. http://www.epa.gov)

DIN 38408-23, Ausgabe:1987-11: Deutsche Einheitsverfahren zur Wasser-, Abwasser- und Schlammuntersuchung; Gasf?rmige Bestandteile (Gruppe G); Bestimmung des Sauerstoffs?ttigungsindex (G 23).

Paul L, 1985. Das thermische Regime der Talsperre Saidenbach und einige Beziehungen zwischen abiotischen und biotischen Komponenten. Dissertation, TU Dresden, Fakult?t Bau-, Wasser- und Forstwesen. 84 pp.

Weiss R, 1970. The solubility of nitrogen, oxygen, and argon in water and seawater. Deep-Sea Research 17, 721-35.

Wagner R, 1979. Die Praxis der Bestimmung des biochemischen Sauerstoffbedarfs - Ergebnisse einer Umfrage (Berichtigung und Erg?nzung zur Ver?ffentlichung). Vom Wasser 53, S. 283-285.

See Also

gas_satconc for other gas species and explicit consideration of pressure.

Examples

gas_O2sat(S = 0, t = 20)                  # fresh water, Weiss formula
gas_O2sat(S = 0, t = 20, method = "APHA") # fresh water, APHA formula

## compare this with
gas_satconc(S = 0, t = 20, species = "O2") * molweight("O2") / 1000

T <- seq(0, 30, 0.1)
plot(T, gas_O2sat(S = 0, t = T, method = "APHA"),
  ylab="O2 sat (mg/L)", type = "l", ylim = c(0, 15))
lines(T, gas_O2sat(S = 0, t = T, method = "Weiss"),
  col = "blue", lwd = 2, lty = "dashed")
lines(T, gas_O2sat(S = 5, t = T, method = "Weiss"), col = "green")
lines(T, gas_O2sat(S = 10, t = T, method = "Weiss"), col = "yellow")
lines(T, gas_O2sat(S = 20, t = T, method = "Weiss"), col = "orange")
lines(T, gas_O2sat(S = 35, t = T, method = "Weiss"), col = "red")

legend("bottomleft", 
  col = c("black", "white", "blue", "green", "yellow", "orange", "red"),
  lty = c(1, 0, 2, 1, 1, 1, 1), lwd = c(1,0 ,2, 1, 1, 1, 1),
  legend=c("freshwater formula", "marine formula:", 
          "S = 0", "S = 5", "S = 10", "S = 20", "S = 35"))