Dynamics of O2 and CO2 exchange, photosynthesis, and respiration in rivers from time‐delayed correlations with ideal sunlight

The oxygen exchange constant, photosynthetic rate, and respiration rate for several Swiss rivers have been determined using only the continuous data record of a single oxygen electrode, the measured temperature, and an assumed ideal light intensity curve in conjunction with a simple model rate equation and a novel cross‐correlation computational technique. The method can, in favorable circumstances, be extended to determine also total carbonate dynamics from continuous pH measurements. For the Aare at Bern in March 1974, the oxygen exchange constant was 0.38 h−1, the respiration rate was 0.6 mg liter−1 h−1, and mean photosynthetic rate was 0.28 mg liter−1 The exchange rate for dissolved (but not hydrated or ionized) CO2 was 0.91 times that for dissolved oxygen, and the ratio of O2 molecules released to CO2 molecules consumed during photosynthesis was about 1.2.