Langone¹, L., M. Ravaioli¹, A. Malaguti ², F. Giglio¹, P. Giordani¹ and M. Frignani¹

¹ISMAR-CNR, Sezione Geologia Marina, Bologna, Italy and ²ENEA, AMB. CAT. FRAL., Bologna, Italy, Tel: +39 051 6398870, Fax: +39 051 6398940, E-mail: langone@igm.bo.cnr.it

Vertical budgets of organic carbon and biogenic silica in the western Ross Sea, Antarctica

The assessment of vertical budgets provides very useful quantitative information on the basic steps of biogeochemical cycling, from production in the surface waters to burial into the sediments. The Southern Ocean in general, and the Ross Sea in particular, are well suited areas for these studies because their high, silica-based primary productivity may play a major role in the global CO₂ balance. In this contribution we discuss the data sets obtained from two working stations located in the Ross Sea Polynya and Joides Basin. Moored instruments were maintained over the period 1995-2000 as a part of the Project BIOSESO of the Italian National Research Program for Antarctica (PNRA). The two stations had been originally chosen as representative of areas characterized by different sea-ice conditions and presumably different levels of primary production. The data sets include new production by ¹⁵NO₃^- uptake, downward fluxes measured by sediment traps, benthic and burial fluxes of particulate organic carbon and biogenic silica, pore water contents of dissolved nutrients and carbon. Processes such as nutrient regeneration, lateral transport, sediment accumulation and early diagenesis of biogenic elements will be addressed as a function of oceanographic conditions and seasonal forcing.