Oxygen concentration in water as a function of temperature

[gwand]

To give you an idea of the quantitative difference (at standard atmospheric pressure and assuming freshwater):

• At 55°F (approximately 12.8°C), freshwater can hold around 10.5 mg/L to 10.6 mg/L of dissolved oxygen.
• At 75°F (approximately 23.9°C), freshwater can hold around 8.3 mg/L to 8.4 mg/L of dissolved oxygen.

 

[MaloK]

This phenomena is exponential and at 81F you will still have around 7.7-7.8.

Turbulence versus respiration versus photosynthesis.

 

[Uberhoust]

https://www.waterboards.ca.gov/water_issues/programs/swamp/docs/cwt/guidance/3110en.pdf, there are a lot of different charts available.

This phenomena is exponential and at 81F you will still have around 7.7-7.8.

I was going to suggest it was a logarithmic relationship but when reviewing the relationship I came across this paper. https://www.iosrjournals.org/iosr-jm/papers/Vol12-issue1/Version-2/D012122427.pdf. I don't have time to go through that math, and the paper also includes the biological component.

It is important to note that the values are based on the water, temperature, and pressure being at equilibrium. If there is a source or sink of O2 or if the water, temp or pressure is changing then the dissolved O2 will be at different concentrations.

 

[MaloK]

https://www.waterboards.ca.gov/water_issues/programs/swamp/docs/cwt/guidance/3110en.pdf, there are a lot of different charts available.


I was going to suggest it was a logarithmic relationship but when reviewing the relationship I came across this paper. https://www.iosrjournals.org/iosr-jm/papers/Vol12-issue1/Version-2/D012122427.pdf. I don't have time to go through that math, and the paper also includes the biological component.

It is important to note that the values are based on the water, temperature, and pressure being at equilibrium. If there is a source or sink of O2 or if the water, temp or pressure is changing then the dissolved O2 will be at different concentrations.

Yeah, exponential was not a good word choice.