Solubility of Atmospheric Gases in Brackish and Marine Waters

This chapter presents tabular information on the standard air saturation concentration (moist air at 1 atm) for oxygen, nitrogen, argon, and carbon dioxide gas in terms of μmol/kg, mg/L, and as Bunsen coefficients L real gas/(L atm) and mg real gas/(L mmHg) for 0–40°C in marine waters. Values are given at coarse salinity intervals for 0–40 g/kg (which embraces the range likely to be encountered in most common nearshore conditions) and at finer intervals for 33–37 g/kg for open water conditions. Because the mole fraction of carbon dioxide in the atmosphere is changing, solubility information is provided for 2010 (390 μatm) and for 2030 (440 μatm) based on projected atmospheric values. Tabular information is also provided to allow computation of standard air saturation concentration of carbon dioxide gas directly as a function of atmospheric mole fraction. Equations and tabular information are provided to allow conversion of concentrations in mg/L to partial pressures in mmHg. Using the equations presented in Chapter 1, air saturation concentrations (at local barometric pressure) and solubility of arbitrary gas composition mixtures can be computed. Sample problems are included for representative examples.