The ballasting effect of Saharan dust deposition on aggregate dynamics and carbon export: Aggregation, settling, and scavenging potential of marine snow
van der Jagt, H.; Friese, C.; Stuut, J-B W.; Fischer, G.; Iversen, M.H. (2018). The ballasting effect of Saharan dust deposition on aggregate dynamics and carbon export: Aggregation, settling, and scavenging potential of marine snow. Limnol. Oceanogr. 63(3): 1386-1394. https://dx.doi.org/10.1002/lno.10779
Additional data:
In: Limnology and Oceanography. American Society of Limnology and Oceanography: Waco, Tex., etc. ISSN 0024-3590; e-ISSN 1939-5590, more
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| Authors | | Top |
- van der Jagt, H.
- Friese, C.
- Stuut, J-B W., more
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- Fischer, G.
- Iversen, M.H.
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| Abstract |
Lithogenic material such as Saharan dust can be incorporated into organic aggregates and act as ballast,potentially enhancing the marine carbon export via increased sinking velocities of aggregates. We studiedthe ballasting effects of Saharan dust on the aggregate dynamics in the upwelling region off Cape Blanc(Mauritania). Aggregate formation from a natural plankton community exposed to Saharan dust depositionresulted in higher abundance of aggregates with higher sinking velocities compared to aggregate formationwith low dust. This higher aggregate abundance and sinking velocities potentially increased the carbonexport 10-fold when the aggregates were ballasted by Saharan dust. After aggregate formation in the surfacewaters, subsequent sinking through suspended Saharan dust minerals had no influence on aggregate sizes,abundance, and sinking velocities. We found that aggregates formed in the surface ocean off Mauritaniawere already heavily ballasted with lithogenic material and could therefore not scavenge any additionalminerals during their descent. This suggests that carbon export to the deep ocean in regions with high dustdeposition is strongly controlled by dust input to the surface ocean while suspended dust particles in deeperwater layers do not significantly interact with sinking aggregates. |
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