FN Archimer Export Format
PT J
TI The export flux of particulate organic carbon derived from 210Po∕210Pb disequilibria along the North Atlantic GEOTRACES GA01 transect: GEOVIDE cruise
BT 
AF Tang, Yi
   Lemaitre, Nolwenn
   Castrillejo, Maxi
   Roca-Martí, Montserrat
   Masqué, Pere
   Stewart, Gillian
AS 1:1,2;2:3;3:4,5;4:5,6;5:5,7;6:1,2;
FF 1:;2:;3:;4:;5:;6:;
C1 Earth and Environmental Sciences, the Graduate Center, City University of New York, New York, USA
   School of Earth and Environmental Sciences, Queens College, City University of New York, Flushing, USA
   Department of Earth Sciences, Institute of Geochemistry and Petrology, ETH-Zürich, Zürich, Switzerland
   Laboratory of Ion Beam Physics, ETH-Zürich, Otto Stern Weg 5, Zürich, 8093, Switzerland
   Institut de Ciència i Tecnologia Ambientals and Departament de Física, Universitat Autònoma de Barcelona, Barcelona, Spain
   Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
   School of Science and Centre for Marine Ecosystems Research, Edith Cowan University, Joondalup, Western Australia, Australia
C2 CITY UNIV NEW YORK, USA
   CITY UNIV NEW YORK, USA
   ETH ZURICH, SWITZERLAND
   ETH ZURICH, SWITZERLAND
   UNIV AUTONOMA BARCELONA, SPAIN
   WHOI, USA
   UNIV EDITH COWAN, AUSTRALIA
IF 3.48
TC 10
UR https://archimer.ifremer.fr/doc/00485/59668/62731.pdf
   https://archimer.ifremer.fr/doc/00485/59668/62732.pdf
   https://archimer.ifremer.fr/doc/00485/59668/62733.pdf
LA English
DT Article
CR GEOVIDE
BO Pourquoi pas ?
AB 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 ocean varied spatially within our study region. Export fluxes of POC ranged from negligible to 10 mmol C m−2 d−1, with enhanced POC export in the Labrador Sea. The cruise track was characterized by overall low POC export relative to net primary production (export efficiency < 1 %–15 %), but relatively high export efficiencies were seen in the basins where diatoms dominated the phytoplankton community. The particularly low export efficiencies in the Iberian Basin, on the other hand, were explained by the dominance of smaller phytoplankton, such as cyanobacteria or coccolithophores. POC fluxes estimated from the 210Po∕210Pb and 234Th∕238U disequilibria agreed within a factor of 3 along the transect, with higher POC estimates generally derived from 234Th. The differences were attributed to integration timescales and the history of bloom events. 
PY 2019
PD JAN
SO Biogeosciences
SN 1726-4170
PU Copernicus GmbH
VL 16
IS 2
UT 000456710800001
BP 309
EP 327
DI 10.5194/bg-16-309-2019
ID 59668
ER

EF