Journal cover Journal topic
Biogeosciences An interactive open-access journal of the European Geosciences Union
Biogeosciences, 6, 2025-2039, 2009
https://doi.org/10.5194/bg-6-2025-2009
© Author(s) 2009. This work is distributed under
the Creative Commons Attribution 3.0 License.
 
06 Oct 2009
Coccolithophore response to climate and surface hydrography in Santa Barbara Basin, California, AD 1917–2004
M. Grelaud1, A. Schimmelmann2, and L. Beaufort1 1CEREGE, Europôle méditerranéen de l'Arbois, BP80, 13545 Aix-en-Provence Cedex 4, France
2Department of Geological Sciences, Indiana University, 1001 East Tenth Street, Bloomington, Indiana, 47405-1403, USA
Abstract. The varved sedimentary AD 1917–2004 record from the depositional center of the Santa Barbara Basin (SBB, California) was analyzed with monthly to triannual resolution to yield relative abundances of six coccolithophore species representing at least 96% of the coccolithophore assemblage. Seasonal/annual relative abundances respond to climatic and surface hydrographic conditions in the SBB, whereby (i) the three species G. oceanica, H. carteri and F. profunda are characteristic of the strength of the northward flowing warm California Counter Current, (ii) the two species G. ericsonii and G. muellerae are associated with the cold equatorward flowing California Current, (iii) and E. huxleyi appears to be endemic to the SBB. Spectral analyses on relative abundances of these species show that all are influenced by the El Niño Southern Oscillation (ENSO) and/or by the Pacific Decadal Oscillation (PDO). Increased relative abundances of G. oceanica and H. carteri are associated with warm ENSO events, G. muellerae responds to warm PDO events and the abundance of G. ericsonii increases during cold PDO events. Morphometric parameters measured on E. huxleyi, G. muellerae and G. oceanica indicate increasing coccolithophore shell carbonate mass from ~1917 until 2004 concomitant with rising pCO2 and sea surface temperature in the region of the SBB.

Citation: Grelaud, M., Schimmelmann, A., and Beaufort, L.: Coccolithophore response to climate and surface hydrography in Santa Barbara Basin, California, AD 1917–2004, Biogeosciences, 6, 2025-2039, https://doi.org/10.5194/bg-6-2025-2009, 2009.
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