Oxygen solubility in evaporated seawater as a function of temperature and salinity

Most studies of oxygen solubility values for high salinity conditions have used synthetic solutions. The object of this study is therefore to propose an equation, valid for high salinity conditions, based on the analysis of oxygen saturation in evaporated seawater. In this study, the solubility of oxygen in evaporated seawater has been determined over a temperature range of 8–35°C and with salinity values of up to 133‰. Based on experimental data, an equation is proposed that introduces a S ² (salinity) term, at 1 atm pressure, giving increased importance to salinity. The equation provides a valid means of predicting the amount of dissolved oxygen in this range of temperatures and salinities. In addition, for high salinity conditions, with this equation there is no need to extrapolate other established equations, which are less accurate at salinities higher than 40‰. The use of the proposed equation offers a more precise way of calculating oxygen solubility in seawater at high salinity values (up to 133‰), and small deviations from experimental values, of the order of 2 μmol kg⁻¹, are obtained. Handling editor: J. Melack