Author:
Guerreiro C. V.,Ziveri P.,Cavaleiro C.,Stuut J.-B. W.
Abstract
AbstractAtmospheric dust deposition can modulate the earth’s climate and atmospheric CO2 through fertilising the ocean (nutrient source) and by accelerating the biological carbon pump through fuelling the ballasting process. To distinguish the biogeochemical effects of Saharan dust with respect to fertilization and ballasting, and to gain a broader perspective on the coccolith calcite Sr/Ca in relation to the drivers of coccolith export production, we determined the coccolith-Sr/Ca from a one-year (2012–2013) time-series sediment trap record in the western tropical North Atlantic (M4—49°N/12°W). High Sr/Ca were linked to enhanced export production in the upper part of the photic zone, most notably under windier, dry, and dustier conditions during spring. Attenuated Sr/Ca in the autumn probably reflect a combination of lower Sr-incorporation by dominant but small-size placolith-bearing species and the presence of “aged” coccoliths rapidly scavenged during a highly productive and usually fast export event, likely added by (wet) dust ballasting. Higher Sr/Ca observed in the large coccolith size fractions support the existing notion that larger-sized coccolithophores incorporate more Sr during calcification under the same environmental conditions. The presence of the abnormally Sr-rich species Scyphosphaera apsteinii is also shown in the separated large fraction of our Sr/Ca seasonal data.
Funder
European Commission
Fundação para a Ciência e a Tecnologia
European Space Agency
CALMED
Generalitat de Catalunya MERS
European Research Council
Publisher
Springer Science and Business Media LLC
Reference52 articles.
1. Moulin, C. & Chiapello, I. Impact of human-induced desertification on the intensification of Sahel dust emission and export over the last decades. Geophys. Res. Lett. 33, L18808. https://doi.org/10.1029/2006GL025923 (2006).
2. Mirzabaev, A. et al. Desertification. In Climate Change and Land: An IPCC Special Report on Climate Change, Desertification, Land Degradation, Sustainable Land Management, Food Security, and Greenhouse Gas Fluxes in Terrestrial Ecosystems (eds Shukla, P. R. et al.) (Springer, 2019).
3. Martin, J. H. Glacial-Interglacial CO2 change: The iron hypothesis. Paleoceanography 5, 1–13. https://doi.org/10.1029/PA005i001p00001 (1990).
4. Coale, K. H. et al. A massive phytoplankton bloom induced by an ecosystem-scale iron fertilization experiment in the equatorial Pacific Ocean. Nature 383, 495–501 (1996).
5. Boyd, P. W. et al. Mesoscale iron enrichment experiments 1993–2005: Synthesis and future directions. Science 315, 612–617. https://doi.org/10.1126/science.1131669 (2007).
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