A high resolution transect of dissolved barium in the Southern Ocean

The dissolved Barium (Bad) distribution in the whole water column was examined along the WOCE SR3 line in the Southern Ocean (Australian sector, late winter‐spring 2001). The high sampling resolution offered an excellent opportunity to relate the Bad distribution to frontal structures and the water masses. Such a high resolution was not achieved in previous Southern Ocean studies and showed the tight overprinting of the frontal zones by Bad gradients. Hydrodynamic control on Bad is evident in the case of Antarctic Bottom Water formation, westward flow of Tasman Sea waters and return flow of an eddy of the SubAntarctic Front. However biogeochemical processes are also acting, as witnessed by enhanced Bad contents in deep waters of the SubAntarctic Front zone and by a local mesopelagic minimum in the Inter Polar Front Zone. These features are respectively ascribed to the dissolution of Ba‐rich phases and Ba transfer from solution to particles.