Will dissolved oxygen increase in a water sample inside a jar?

[Frankenstein19]

TL;DR

I know dissolved oxygen increases in water as temperature decreases.

But if I pour some water in a jar and close it, and then decrease temperature, will the DO increase if the sample is just laying in the jar? (No agitation)

If I have 100mL inside a glass with a closed cap. I take the cap off, measure DO, put the cap back on and decrease the temperature 20 degrees. No agitation of any sort.

Does the DO increase?

 

[BillTre]

The amount of oxygen dissolved in the water remains the same.
However, the percentage oxygen saturation in the water will increase.
10% oxygen saturation is the max amount of oxygen the water can maintain in solution under the conditions.

100% oxygen saturation will be less at higher temperatures, but the absolute amount of oxygen will will not. Therefore the percentage oxygen saturation will go up in the sample.

However, it possible that some excess gas will leave solution and go into the atmosphere in the enclose atmosphere of the glass, if any (especially if its about 100% saturation). This will reduce the absolute amount of dissolved oxygen in the water and increase the pressure of the atmosphere in the glass (if its sealed). This is like CO₂ in a sealed a bottle of soda.