Global sediment trap synthesis; source data from 1987-1999 (U.S. JGOFS Synthesis & Modeling Phase project results)

<p>A large number of moored, longer term, time-series deep-sea sediment traps have been deployed by our group and others in the world ocean over the past two decades, and more are being deployed every year. We are proposing a compilation of published and unpublished sediment trap flux data that will result in an integrated and consistent data set. Our goal is to refine our present estimates of global and regional fluxes and remineralization of biogenic material (organic C, calcite, aragonite, opal, N, and P) and lithogenic particle input in the ocean interior. More specifically, we are proposing a 3-year project to</p>
<ol>
<li>Build synoptic maps of organic carbon, nitrogen, phosphorus, carbonate (aragonite and calcite), opal, and lithogenic fluxes to the ocean interior;</li>
<li>Document systematic regional variations in the seasonality of particle flux and composition;</li>
<li>Evaluate the extent of organic matter remineralization and nutrients (N and P) regeneration within the upper 1 km by comparing fluxes at 1 km with synoptic estimates of export production;</li>
<li>Estimate the recycling of organic C, N, P, opal, and carbonate (calcite vs. aragonite) in water below 1 km by comparing fluxes measured at different depths, after correction for trapping efficiency using a radiochemical method based on the scavenging of ²³⁰Th and ²³¹Pa;</li>
<li>Document the relative importance of coccolith vs. foraminifera vs. pteropod in establishing the fluxes of CaCO₃, and diatoms vs. silicoflagellates vs. radiolarians in establishing the flux of biogenic SiO₂;</li>
<li>Estimate the extent of recycling in surface sediment by comparing sediment trap flux data with ²³⁰Th-normalized fluxes measured in sediment underlying each trap site;</li>
<li>Compare fluxes of lithogenic particles with estimates of dust input into ocean basins to assess the link between aeolian input and the accumulation of terrigenous matter on the seafloor.</li>
</ol>
<p>
We will compare our results with synoptic data sets on primary production, plankton ecology, export flux, surface nutrient concentration, upper water column structure, aeolian dust input, and surface water pCO₂to distinguish environmental or ecological factors that may affect the export and degradation of biogenic material in the deep-sea (e.g. f-ratio, seasonality, food web structure, &quot;ballast&quot; effect from aeolian dust). This synthesis effort will provide an important basis for introducing a more accurate particle flux field and better constrained algorithms for the recycling of biogenic material in GCM models.</p>
<p>Data from additional sediment trap deployments will be added to this data set as they become available.</p>