2004. Inverse modeling of particulate organic carbon fluxes

• Main Authors: R. Schlitzer, R. Usbeck, G. Fischer
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: Springer-Verlag
• Subjects: Antarctic; The Antarctic; Antarc*
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.462.7705; http://epic.awi.de/5689/1/Sch2002p.pdf

Abstract: The biological production of particulate material near the ocean surface and its subsequent remineralization during sinking and after deposition on the seafloor strongly affect the distribution of oxygen, dissolved nutrients and carbon in the ocean. Dissolved nutrient distributions therefore reveal the underlying biogeochemical processes, and these data can be used to determine rates of production, remineralization and accumulation with the aid of inverse techniques. Here, an ocean circulation, biogeochemical model that exploits the existing large sets of hydrographic, oxygen, nutrient and carbon data is presented and results for the export production of particulate organic matter, vertical fluxes in the water column, and sedimentation rates are presented. In the model, the integrated export flux of particulate organic carbon (POC) in the South Atlantic amounts to about 1300 Tg C yr-1 (equivalent to 1.3 Gt C yr-1), most of which occurring in the Benguela/Namibia upwelling region and in a zonal band following the course of the Antarctic Circumpolar Current (ACC). Remineralization of POC in the upper water column is intense, and only about 7 % of the export reaches a depth of 2000 m. Comparison of modeled particle fluxes with sediment trap data suggests that shallow traps tend to underestimate the downward flux, whereas the deep traps seem to be affected by the lateral input of material and apparently overestimate the vertical flux. These findings