The seasonal cycle of δ.sup.3C.sub.DIC in the North Atlantic subpolar gyre

This study introduces for the first time the [delta].sup.13 C.sub.DIC seasonality in the North Atlantic subpolar gyre (NASPG) using [delta].sup.13 C.sub.DIC data obtained in 2005-2006 and 2010-2012 with dissolved inorganic carbon (DIC) and nutrient observations. On the seasonal scale, the NASPG is c...

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Bibliographic Details
Published in:Biogeosciences 2014-03, Vol.11 (6), p.1683
Main Authors: Racapé, V, Metzl, N, Pierre, C, Reverdin, G, Quay, P. D, Olafsdottir, S. R
Format: Article
Language:English
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Summary:This study introduces for the first time the [delta].sup.13 C.sub.DIC seasonality in the North Atlantic subpolar gyre (NASPG) using [delta].sup.13 C.sub.DIC data obtained in 2005-2006 and 2010-2012 with dissolved inorganic carbon (DIC) and nutrient observations. On the seasonal scale, the NASPG is characterized by higher [delta].sup.13 C.sub.DIC values during summer than during winter, with a seasonal amplitude between 0.70 ± 0.10‰ (August 2010-March 2011) and 0.77 ± 0.07‰ (2005-2006). This is mainly attributed to photosynthetic activity in summer and to a deep remineralization process during winter convection, sometimes influenced by ocean dynamics and carbonate pumps. There is also a strong and negative linear relationship between [delta].sup.13 C.sub.DIC and DIC during all seasons. Winter data also showed a large decrease in [delta].sup.13 C.sub.DIC associated with an increase in DIC between 2006 and 2011-2012, but the observed time rates (-0.04‰ yr.sup.-1 and +1.7 μmol kg.sup.-1 yr.sup.-1) are much larger than the expected anthropogenic signal.
ISSN:1726-4170
1726-4189