Carbon monoxide in the South Pacific Ocean1

During a recent oceanographic cruise (November 1972) of the U.S. Coast Guard ice-breaker GLACIER, both surface sea water and atmospheric samples were collected for CO analysis. The ship followed a cruise track from Long Beach, California to McMurdo Sound in the Antarctic. Atmospheric carbon monoxide concentrations in the south Pacific were found to be much lower than those measured in the north Pacific, 0.04 ppm to 0.13 ppm, respectively. CO concentrations in sea water of the south Pacific range between 1 and 30 × 10^–5 ml/l and compare favorably to levels measured in the oceans of the northern hemisphere. In all sea water samples, the carbon monoxide was supersaturated relative to the surrounding atmosphere. Sea water carbon monoxide concentrations were highest in regions of upwelling or water convergence zones. These areas were also associated with high biological activity.

Ten vertical profiles of carbon monoxide in sea water were obtained between Long Beach and McMurdo Sound. In general, the carbon monoxide concentration was highest in the upper 30 m with a steady decrease to near 0 concentration at 100 me. Carbon monoxide was also measured in sea ice collected in the Antarctic. The highest concentrations of carbon monoxide was found to be on the bottom of the sea ice. The bottom ice had heavy concentrations of brown algae which penetrated half a meter into the ice. The surface snow exhibited concentrations of carbon monoxide which were comparable to those found in the surface sea water for the same area.