The export flux of particulate organic carbon derived from 210Po/210Pb disequilibria along the North Atlantic GEOTRACES GA01 transect: GEOVIDE cruise ...

• Main Authors: Tang, Yi, Lemaitre, Nolwenn, Castrillejo, Maxi, Roca-Marti, Montserrat, Masqué, Pere, Stewart, Gillian
• Format: Article in Journal/Newspaper
• Language: English
• Published: ETH Zurich 2019
• Subjects: Greenland; North Atlantic
• Online Access: https://dx.doi.org/10.3929/ethz-b-000322742; http://hdl.handle.net/20.500.11850/322742

The disequilibrium between 210Po activity and 210Pb activity in seawater samples was determined along the GEOTRACES GA01 transect in the North Atlantic during the GEOVIDE cruise (May–June 2014). A steady-state model was used to quantify vertical export of particulate 210Po. Vertical advection was incorporated into one version of the model using time-averaged vertical velocity, which had substantial variance. This resulted in large uncertainties for the 210Po export flux in this model, suggesting that those calculations of 210Po export fluxes should be used with great care. Despite the large uncertainties, there is no question that the deficits of 210Po in the Iberian Basin and at the Greenland Shelf have been strongly affected by vertical advection. Using the export flux of 210Po and the particulate organic carbon (POC) to 210Po ratio of total (> 1 µm) particles, we determined the POC export fluxes along the transect. Both the magnitude and efficiency of the estimated POC export flux from the surface ... : Biogeosciences, 16 (2) ...