Temperature affects the equilibrium constant for the solvation...

Temperature affects the equilibrium constant for the solvation process (k): the solubility of O2 and CO2 is increased at low temperatures. Thus at low temperatures, there will be a lower partial pressure for a higher dissolved concentration of gas. Oxygen and carbon dioxide increase in solubility as water temperature decreases, so their partial pressures will be less. Gases and liquids behave differently. Gases dissolved in liquids even more so. Put simply, as gas molecules are excited (temperatue increases) they move faster, escaping solution and reducing the amount dissolved (partial pressure.) Simple physics.