wvp: Water vapor pressure as a function of water temperature and...

In denis-chabot/fishMO2: Calculate and Plot SMR, O2crit and SDA, and convert between oxygen units

Description

Calculates water vapor pressure, given water temperature and salinity, using a variety of methods. This is required to convert partial pressure of oxygen into saturation or concentration units and vice-versa.

Usage

wvp(
  t,
  s = 0,
  method = c("IAPWS", "BensonKrause", "GreenCarritt", "WMO2008", "Antoine", "Weiss",
    "GoffGratch"),
  sal_method = c("Chabot", "Green", "none")
)

Arguments

t	Temperature in °C
s	Salinity in parts per thousand
method	One of "IAPWS", "BensonKrause", "GreenCarritt","WMO2008", "Antoine", "Weiss", "GoffGratch". See Details.
sal_method	One of "Chabot", "Green" or "none". See Details.

Details

Output: water vapor pressure above fresh or sea water in kPa.

Note: this function is not intended to calculate vapor pressure above ice. Also, water vapor pressure is not affected by atmospheric pressure

Methods for vapor pressure calculation above fresh water:

IAPWS

This is the 'official' formulation from the International Association for the Properties of Water and Steam (Wagner & Pruss 1993), Eq. 2.5 p. 399. The valid range of this formulation is 273.16 <= K <= 647.096 and is based on the ITS90 temperature scale.

BensonKrause

Eq. 23 of Benson and Krause, 1980

GreenCarritt

Green & Carritt 1967 (see also table 2 Benson & Krause 1984) without salinity correction, in atm converted to kPa

WMO2008

Annex 4B, Guide to Meteorological Instruments and Methods of Observation, WMO Publication No 8, 7th edition, Geneva, 2008.

Antoine

http://www.watervaporpressure.com

Weiss

Weiss & Price 1980 eq 10 p. 350, in atm converted to kPa

GoffGratch

Smithsonian Meteorological Tables, 5th edition, p. 350, 1984, in hPa then converted to kPa

Methods for salinity correction:

Chabot

My own polynomial fit passing through origin to Robinson 1954's data, Table II p. 451 gives values of delta vp for different chlorinities. Chlorinity changed into salinity according to Lyman (1969)

Green

From table 2 in Benson & Krause (1984)

none

Removes salinity correction, same as leaving s to its default value of zero

Value

A vector of same length as parameter t

Warnings

s must be of length 1 or same length as t. This is not checked by the function at present so errors could occur if this is not respected.

Note

This assumes that air temperature above the water surface is that of the water. The effect of salinity is negligible, but it is nevertheless included in the calculation if the user provides salinity.

Author(s)

Denis Chabot

References

Benson B.B. and Krause D.Jr. (1980) The concentration and isotopic fractionation of gases dissolved in freshwater in equilibrium with the atmosphere. 1. Oxygen. Limnology and Oceanography, 25, 662-671.

Benson B.B. and Krause D.Jr. (1984) The concentration and isotopic fractionation of oxygen dissolved in freshwater and seawater in equilibrium with the atmosphere. Limnology and Oceanography, 29, 620-632.

Green, E. J. and Carritt, D. E. (1967) New tables for oxygen saturation of seawater. Journal of Marine Research, 25, 140-147.

Lyman, J. (1969) Redefinition of salinity and chlorinity. Limnology and Oceanography, 27, 928-929.

Robinson R. A. (1954) The vapour pressure and osmotic equivalence of sea water. Journal of the Marine Biological Association of the United Kingdom, 33, 449-455.

Wagner, W. and Pruss, A. (1993) International Equations for the Saturation Properties of Ordinary Water Substance. Revised According to the International Temperature Scale of 1990. Addendum to J. Phys. Chem. Ref. Data 16, 893 (1987) Journal of Physical and Chemical Reference Data, 22, 783. http://dx.doi.org/10.1063/1.555926.

Wagner, W. & Pruss, A. (2002) The IAPWS formulation 1995 for the thermodynamic properties of ordinary water substance for general and scientific use. Journal of Physical and Chemical Reference Data, 31(2), 387-535.

Examples

wvp(t=c(0,5,10))
wvp(t=c(0,5,10), s=35)

denis-chabot/fishMO2 documentation built on July 16, 2020, 1:53 a.m.