9216626 MULLER-KARGER This is a study of the relation of near surface biogeochemical processes to the downward flux of particulate materials along a continental margin where down-slope lateral losses into the ocean's interior are minimal. Specifically, low-cost ocean margin time series station in the Cariaco Basin, a depression located on the continental margin of the southern Caribbean Sea, will be inflemeated. Monthly hydrographic casts and bi-weekly sediment flux at 4 depths using automated moore traps will the conducted high resolution satellite data will be collected using an antenna located in Caracas, Benezuela. This program is identified is as CARIACO (CArbon Retention In A Colored Ocean). The goals of the CARIACO program are to: a) quantify oceanographic processes that affect the vertical flux of nutrients, carbon uptake, and carbon deposition, including the interaction between wind speed, sea level (as an indicator of geostrophic current strength), river discharge, sea surface temperature, and irradiance above an anoxic basin; to define variability in biogeochemcial fluxes in an area affected by seasonal upwelling and river discharge; c) quantify the relative importance of primary production versus terrigenous inputs of particulate and dissolved materials in the downward flux and sediments storage; d) determine the seasonal taxonomic composition of plankton in the water column, with emphasis on vertical variations of phytoplankton and foraminifera species; e) develop a two-dimensional numerical model the allows examination of the annual cycle of population responses, vertical biogenic fluxes, and degradation of detritus at depth; and f) examine the relationship between water-column oceanographic processes and sediment fluxes in order to understand the origin of sediment varves and their relationship to past climate change.
