Cooperative Studies of Southern Ocean Biogeochemistry

Princeton University, Princeton NJ

Investigators

Abstract

The proposed work will obtain an extensive oceanic data set that will define net production, gross production, iron sufficiency, nutrient concentrations, and irradiance at mixed layer depths over a large part of the Southern Ocean. The results will be used to investigate the relationship between net and gross production and factors influencing these variables, and will have implications for the evolution of the nutrient and carbon concentrations in the Southern Ocean euphotic zone, the biogeochemistry of high nutrient-low chlorophyll water bodies, the influence of Southern Ocean biochemical processes on atmospheric carbon dioxide, and the fertility of the global oceans. The observed data set will consist of the dissolved oxygen/argon ratio, a measure of biological oxygen supersaturation, and the triple isotope composition of oxygen, a measure of the fraction of the dissolved oxygen pool derived from photosynthesis. Surface water samples will be collected on the L.M. Gould and on ships of opportunity, and analyzed at the home institution. The work will be carried out in collaborative studies with other independent and established international projects studying Southern Ocean biogeochemistry. These include a French-Australian group working south of Hobart on Astrolabe, an Australian group working in the western Pacific on Aurora Australis, and an Argentine group working between the Drake Passage and South Orkney Islands on Irizar.