Nonequilibrium of carbon monoxide and methane at the air-sea interface

Supersaturation of carbon monoxide was found in the surface waters of the Pacific Ocean on a recent cruise to Hawaii, which confirmed previous findings in the Atlantic. A diurnal cycling effect was observed, with maximum production of CO occurring during daylight hours. When compared to measured atmospheric partial pressures of CO, the concentrations of dissolved CO were found to be 15 to 75 times higher than atmospheric equilibrium values. Measurements of methane made concurrently with those for carbon monoxide showed that in contrast to carbon monoxide only a slight degree of methane supersaturation exists.