Diurnal, seasonal, and spatial variations and flux of carbon monoxide in Jiaozhou Bay, China

Four cruises were conducted in Jiaozhou Bay from January to November in 2008 to study carbon monoxide (CO) distribution, diurnal variation, seasonal variation, and sea-to-air flux. Surface water CO concentration exhibited strong diurnal variations at an anchor station in both April and November, with highest CO concentration 3-5 times higher than minimum values. Diurnal variation (sampling time) exerts an overall pattern on CO distribution, spatially distributed factors impose extra influence. High CO concentrations and fluxes were observed in the eastern, northern, and western parts of the bay, which are close to areas of estuaries, dense population, and high industrialization, reflecting the impact of human activities on CO distribution. Both surface water CO concentrations and sea-to-air fluxes showed seasonal variations, with the highest values in summer and the lowest values in winter. Sea-to-air CO flux in Jiaozhou Bay ranged from 0 to 34.66 μmol m− 2 d− 1 with a mean flux of 4.96 μmol m− 2 d− 1.