Recirculation in the Banda throughflow,traced with dissolved silica

The change of water-mass properties during the flow of waters originating in the Pacific Ocean through the eastern Indonesian archipelago causes an increase of dissolved silica in the layers between 100 and 1500 m depth. The time needed to build up this increase is estimated as 5 years, with contributions of basin-wide upwelling, dissolution of biogenic siliceous debris at depth and vertical diffusion. The dissolved silica distribution suggests a recirculation of Banda Sea Intermediate Water leaving the southern Banda Sea at around 1000 m depth through the Timor Sea and the Seram Sea, and flowing back into the northern Banda Sea. This recirculation is also detectable in the Molucca Sea between 250 and 500 m depth.