Dissolved inorganic carbon and CO₂ fluxes across Jiaozhou Bay air-water interface

On the basis of data collected in the Jiaozhou Bay in June and July 2003, the DIC distribution in seawater is studied, and an average air-sea flux of CO₂ is estimated. The results show that the content of DIC inside the bay is markedly higher than outside the bay in June, but the content of DIC outside the bay is markedly higher than inside the bay in July. The trend of DIC distribution inside the bay is similar, viz. the content is the maximum in the northeast, then decreases gradually toward the west, and the content is the minimum in the west. The total trend of vertical distribution is to increase gradually from surface to bottom. This characteristic of DIC distribution is determined by Jiaozhou Bay hydrology and there is a close relation between DIC and particulate N,P. Average CO₂ flux across the air-sea interface is 0.55 mol/(m²·a) in June and 0.72 mol/(m²·a) in July. Jiaozhou Bay is considered as a net annual source for atmospheric CO₂ in June and July, and the total CO₂ flux from seawater into a atmosphere is about 740 t in June and 969 t in July.