Dissolved organic carbon associated with sinking particles can be crucial for estimates of vertical carbon flux
Noji, T.T.; Børsheim, K.Y.; Rey, F.; Nortvedt, R. (1999). Dissolved organic carbon associated with sinking particles can be crucial for estimates of vertical carbon flux. Sarsia 84(2): 129-135
In: Sarsia. University of Bergen. Universitetsforlaget: Bergen. ISSN 0036-4827; e-ISSN 1503-1128, more
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| Authors | | Top |
- Noji, T.T.
- Børsheim, K.Y.
- Rey, F.
- Nortvedt, R.
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| Abstract |
Sinking particles are a major vehicle of carbon export from surface waters of the ocean and thus their rates of sedimentation are important for assessing the role of the ocean for the sequestration of atmospheric carbon dioxide. Oceanographers often use sediment traps to estimate particle sedimentation. We suggest that the downward transport of carbon via particles may be underestimated, as dissolved organic carbon (DOC) released from trapped particles is not usually considered, thus hindering attempts to “balance” the carbon budget. Latent variable analyses of trap data enabled us to more accurately estimate flux of particulate carbon. In particular, we present a method to separate the fraction of DOC leached from zooplanktonic swimmers from DOC originating from sedimented particles. The latter we term particle-associated DOC (pDOC). The precise impact of this process in different ecosystems may vary. Thus, an application of the statistical procedure should be made for individual sets of sediment-trap data at different locations. Our results from the central Greenland Sea from 1993 to 1995 indicate that the concentration of pDOC was from 25 % to several times the concentration of particulate carbon in individual sediment trap samples collected in three depths. Thus, pDOC was a significant carbon pool for our investigation. We suggest that the potential of pDOC as a “loss” factor in carbon budgets merits consideration in investigations aiming to accurately quantify the downward transport of carbon in the ocean. |
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