Journal cover Journal topic
Climate of the Past An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 3.470 IF 3.470
  • IF 5-year value: 4.009 IF 5-year
    4.009
  • CiteScore value: 3.45 CiteScore
    3.45
  • SNIP value: 1.166 SNIP 1.166
  • IPP value: 3.28 IPP 3.28
  • SJR value: 1.929 SJR 1.929
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 64 Scimago H
    index 64
  • h5-index value: 43 h5-index 43
Discussion papers
https://doi.org/10.5194/cp-2019-131
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/cp-2019-131
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.

Submitted as: research article 29 Oct 2019

Submitted as: research article | 29 Oct 2019

Review status
This discussion paper is a preprint. It is a manuscript under review for the journal Climate of the Past (CP).

Coccolithophore productivity at the western Iberian Margin during the middle Pleistocene (310–455 ka) – evidence from coccolith Sr/Ca data

Catarina Cavaleiro1,2,3, Antje H. L. Voelker2,3, Heather Stoll4,a, Karl-Heinz Baumann5, and Michal Kucera1 Catarina Cavaleiro et al.
  • 1University of Bremen, MARUM - Center for Marine and Environmental Sciences, Leobener Straße 8, 28359 Bremen, Germany
  • 2PMA – Instituto Português do Mar e da Atmosfera, Divisão de Geologia Marinha e Georecursos Marinhos, Avenida Doutor Alfredo Magalhães Ramalho 6, 1495-165 Alges, Portugal
  • 3CCMAR, Centro de Ciências do Mar, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal
  • 4Geology Department, University of Oviedo, C/. Jesús Arias de Velasco s/n, 33005, Oviedo, Spain
  • 5University of Bremen, Geosciences Department, Klagenfurter Straße 2-4, 28359 Bremen, Germany
  • anow at: Department of Earth Sciences, ETH Zürich, Sonneggstrasse 5,8092 Zürich, Switzerland

Abstract. Coccolithophores contribute significantly to the marine primary productivity and play a unique role in ocean biogeochemistry by using carbon for photosynthesis (biological pump) and also for calcification (carbonate pump). Despite the importance of including coccolithophores in global climate models to allow better predictions of the climate system's responses to planetary change, highly uncertain coccolithophore paleoproductivity past reconstructions mostly relied on proxies dependent on accumulation and sedimentation rates, and preservation conditions. In this study we used an independent proxy, based on the coccolith fraction (CF) Sr/Ca ratio, to reconstruct coccolithophore productivity. We used the marine sediment core MD03-2699 from the western Iberian margin (IbM), spanning the glacial/interglacial cycles of Marine Isotope Stage (MIS) 12 to MIS 9. We found that IbM coccolithophore productivity was controlled by changes in the oceanographic conditions, such as in SST, the competition for nutrients with other phytoplankton groups and insolation. Long-term coccolithophore productivity was primarily affected by variations in the dominant water mass. Polar and subpolar surface waters during glacial substages were associated with decreased coccolithophore productivity, with strongest productivity minima being concomitant with Heinrich-type events (HtE). Subtropical, nutrient-poorer waters during interglacial substages, i.e. MIS 11c, might have lead to intensified competition for nutrients with diatoms resulting in intermediate levels of coccolithophore productivity. The transition from interglacial to glacial substages was likely associated with increasing presence of nutrient-richer waters, possibly with lower silica content than riverine discharges and mostly fed by either upwelling or surface waters of northern origin. This minimized the competition with diatoms and coccolithophores reached their productivity maxima. Climatic conditions during colder periods forced coccolithophores to change their phenology contributing to the dissonance between the CF Sr/Ca derived coccolithophore productivity and nannofossil accumulation rate and total alkenone flux, which is interpreted as a consequence of the narrowing yearly time-window for coccolithophore productivity.

Catarina Cavaleiro et al.
Interactive discussion
Status: open (until 24 Dec 2019)
Status: open (until 24 Dec 2019)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement
Catarina Cavaleiro et al.
Catarina Cavaleiro et al.
Viewed  
Total article views: 168 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
124 43 1 168 0 2
  • HTML: 124
  • PDF: 43
  • XML: 1
  • Total: 168
  • BibTeX: 0
  • EndNote: 2
Views and downloads (calculated since 29 Oct 2019)
Cumulative views and downloads (calculated since 29 Oct 2019)
Viewed (geographical distribution)  
Total article views: 144 (including HTML, PDF, and XML) Thereof 144 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Cited  
Saved  
No saved metrics found.
Discussed  
No discussed metrics found.
Latest update: 11 Nov 2019
Publications Copernicus
Download
Citation