The solubility of oxygen decreases as water temperature
increases.This means that warmer surface water requires less
dissolved oxygen to reach 100% air saturation than does deeper,
cooler water.
For example, at sea level (1 atm or 760 mmHg) and 4°C (39°F),
100% air-saturated water would hold 10.92 mg/L of dissolved oxygen.
³ But if the temperature were raised to room temperature, 21°C
(70°F), there would only be 8.68 mg/L DO at 100% air saturation
³.
The solubility value for oxygen at various temperature in vogue
for long time were those given by Treusdale et al (1955); these
were re-estimated using improved Henry coefficients (Benson &
Krauz, 1980), discussed in Cole (1983).
Cold water holds more dissolved oxygen than warm water.