Journal metrics

Journal metrics

  • IF value: 3.174 IF 3.174
  • IF 5-year value: 3.841 IF 5-year 3.841
  • CiteScore value: 3.48 CiteScore 3.48
  • SNIP value: 1.078 SNIP 1.078
  • SJR value: 1.981 SJR 1.981
  • IPP value: 3.38 IPP 3.38
  • h5-index value: 42 h5-index 42
  • Scimago H index value: 58 Scimago H index 58
Discussion papers | Copyright
https://doi.org/10.5194/cp-2018-42
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

Research article 26 Apr 2018

Research article | 26 Apr 2018

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

The 405 kyr and 2.4 Myr eccentricity components in Cenozoic carbon isotope records

Ilja J. Kocken1, Margot J. Cramwinckel1, Richard E. Zeebe2, Jack J. Middelburg1, and Appy Sluijs1 Ilja J. Kocken et al.
  • 1Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Princetonlaan 8a, 3584 CB, Utrecht, the Netherlands
  • 2Department of Oceanography, University of Hawai'i at Mānoa, 1000 Pope Road, HI 96822, Honolulu, USA

Abstract. Cenozoic stable carbon (δ13C) and oxygen (δ18O) isotope ratios of deep-sea foraminiferal calcite co-vary with the 405kyr eccentricity cycle, suggesting a link between orbital forcing, the climate system, and the carbon cycle. Variations in δ18O are partly forced by ice-volume changes that have mostly occurred since the Oligocene. The cyclic δ13C–δ18O co-variations are found in both ice-free and glaciated climate states, however. Consequently, there should be a mechanism that forces the δ13C cycles independently of ice-dynamics. In search of this mechanism, we simulate the response of several key components of the carbon cycle to orbital forcing in the Long-term Ocean-atmosphere-Sediment CArbon cycle Reservoir model (LOSCAR). We force the model by changing the burial of organic carbon in the ocean with various astronomical solutions and noise, and study the response of the main carbon cycle tracers. Consistent with previous work, the simulations reveal that low frequency oscillations in the forcing are preferentially amplified relative to higher frequencies. However, while oceanic δ13C mainly varies with a 405kyr period in the model, the dynamics of dissolved inorganic carbon in the oceans and of atmospheric CO2 are dominated by the 2.4Myr cycle of eccentricity. This implies that the total ocean and atmosphere carbon inventory is strongly influenced by carbon cycle variability that exceeds the time scale of the 405kyr period (such as silicate weathering). To test the applicability of the model results, we assemble a long (~22Myr) δ13C and δ18O composite record spanning the Eocene to Miocene (34 to 12Ma) and perform spectral analysis to assess the presence of the 2.4Myr cycle. We find that, while the 2.4Myr cycle appears to be overshadowed by long-term changes in the composite record, it is is present as an amplitude modulator of the 405 and 100kyr eccentricity cycles.

Download & links
Ilja J. Kocken et al.
Interactive discussion
Status: final response (author comments only)
Status: final response (author comments only)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Login for Authors/Editors] [Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement
Ilja J. Kocken et al.
Ilja J. Kocken et al.
Viewed
Total article views: 834 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
685 133 16 834 30 11 13
  • HTML: 685
  • PDF: 133
  • XML: 16
  • Total: 834
  • Supplement: 30
  • BibTeX: 11
  • EndNote: 13
Views and downloads (calculated since 26 Apr 2018)
Cumulative views and downloads (calculated since 26 Apr 2018)
Viewed (geographical distribution)
Total article views: 834 (including HTML, PDF, and XML) Thereof 831 with geography defined and 3 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Cited
Saved
No saved metrics found.
Discussed
Latest update: 20 Aug 2018
Publications Copernicus
Download
Short summary
Marine organic carbon burial could link the 405 thousand year eccentricity cycle in the long-term carbon cycle to that observed in climate records. Here, we simulate the response of the carbon cycle to astronomical forcing. We find a strong 2.4 million year cycle in the model output, which is present as an amplitude modulator of the 405 and 100 thousand year eccentricity cycles in a newly assembled composite record.
Marine organic carbon burial could link the 405 thousand year eccentricity cycle in the...
Citation
Share