The seasonal cycle of δ 13 C DIC in the North Atlantic subpolar gyre
International audience This study introduces for the first time the δ 13 C DIC seasonality in the North Atlantic subpolar gyre (NASPG) using δ 13 C DIC data obtained in 2005-2006 and 2010-2012 with dissolved inorganic carbon (DIC) and nutrient observations. On the seasonal scale, the NASPG is charac...
Published in: | Biogeosciences |
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Main Authors: | , , , , , |
Other Authors: | , , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2014
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Subjects: | |
Online Access: | https://hal.science/hal-00991675 https://hal.science/hal-00991675/document https://hal.science/hal-00991675/file/bg-11-1683-2014.pdf https://doi.org/10.5194/BG-11-1683-2014 |
Summary: | International audience This study introduces for the first time the δ 13 C DIC seasonality in the North Atlantic subpolar gyre (NASPG) using δ 13 C 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 δ 13 C 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 δ 13 C DIC and DIC during all seasons. Winter data also showed a large decrease in δ 13 C DIC associated with an increase in DIC between 2006 and 2011-2012, but the observed time rates (-0.04‰ yr -1 and +1.7 μmol kg -1 yr -1 ) are much larger than the expected anthropogenic signal. |
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