Neutrally-Buoyant Sediment Traps for Direct Sampling of the Upper Ocean Export Flux

Woods Hole Oceanographic Institution, Woods Hole MA

Investigators

Abstract

ABSTRACT OCE-9912044 Understanding the export flux of particles from the surface ocean to the oceanic interior is an important aspect of the global carbon balance, and as such has great relevance to understanding the dynamics of climate change. Until recently, surface fluxes have been investigated by surface tethered floating sediment traps (STST), but these have been plagued by uncertainties in artifacts inherent in their design. This project will test a new approach to measuring surface flux by way of a neutrally buoyant sediment trap (NBST) for studies of biogeochemical cycling in the upper ocean. The hypothesis to be tested is that direct sampling of the upper ocean export flux can best be accomplished by the use of NBSTs that drift freely with horizontal currents while maintaining a specified depth. The plan is to deploy NBSTs on five cruises in the Sargasso Sea, and measure the 234Th water column inventory and associated trap activity.