PROJECT
DESCRIPTION: |
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 2 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a compilation of published and unpublished sediment trap flux data that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
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Build synoptic maps of organic carbon, nitrogen, phosphorus, carbonate
(aragonite and calcite), opal, and lithogenic fluxes to the ocean interior;
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Document systematic regional variations in the seasonality of particle
flux and composition;
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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;
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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;
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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;
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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;
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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.
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 pCO2 to
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, "ballast" 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.
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INVESTIGATOR
INFORMATION: |
Susumu Honjo
Dept. Geology and Geophysics
Woods Hole Oceanographic Institution
Woods Hole, MA 02543
tel: 508-540-1162
fax: 508-540-9439
shonjo@whoi.edu
web site
Roger Francois (updated: 29 April 2005)
Department of Earth and Ocean Sciences
University of British Columbia
2329 West Mall
Vancouver, BC Canada V6T 1Z4
tel: 604-822-6355
rfrancois@eos.ubc.ca
http://www.eos.ubc.ca/public/people/faculty/R.Francois.html
Steven J. Manganini
Dept. Geology and Geophysics
Woods Hole Oceanographic Institution
Woods Hole, MA 02543
tel: 508-457-2000 x2778
smanganini@whoi.edu
web site
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