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-2018-30
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

Research article 21 Mar 2018

Research article | 21 Mar 2018

Review status
This discussion paper is a preprint. A revision of the manuscript was accepted for the journal Climate of the Past (CP).

Role of the North Atlantic circulation in the mid-Pleistocene transition

Gloria M. Martin-Garcia1, Francisco J. Sierro1, José A. Flores1, and Fátima Abrantes2,3 Gloria M. Martin-Garcia et al.
  • 1Department of Geology, University of Salamanca, Salamanca, Spain
  • 2Marine Geology and Georesources (DivGM), Portuguese Institute for the Sea and Atmosphere, Lisbon, Portugal
  • 3Centre for Marine Sciences at University of Algarve, Faro, Portugal

Abstract. The southwestern Iberian margin is highly sensitive to changes in the distribution of North Atlantic currents, and to the position of oceanic fronts. In this work, the evolution of oceanographic parameters from 812 to 530ka (MIS20-MIS14) is reconstructed, based on the analysis of planktonic foraminifer assemblages from site IODP-U1385 (37°34.285'N, 10°7.562'W; 2585mbsl). By comparing the obtained results with published records from other North Atlantic sites between 41 and 55°N, basin-wide paleoceanographic conditions are reconstructed. Variations of assemblages dwelling in different water masses indicate a major change in the general North Atlantic circulation during MIS16, coinciding with the definite establishment of the 100-ky cyclicity associated to the Mid-Pleistocene Transition. In surface, this change consisted in the re-distribution of water masses, with the subsequent thermal variation, and occurred linked to the northwestward migration of the Arctic Front (AF) and the increase in the North Atlantic Deep Water (NADW) formation. During glacials prior to MIS 16, the NADW formation was very weak, which drastically slowed down the surface circulation; the AF was at a southerly position and the North Atlantic Current (NAC) diverted southeastwards, developing steep south-north, and east-west, thermal gradients and blockading the arrival of warm water, with associated moisture, to high latitudes. During MIS16, the important increase in the meridional overturning circulation, in combination with the north-westward AF shift, allowed the arrival of the NAC to subpolar latitudes, multiplying the moisture availability for ice-sheets growth, which worked as a positive feedback to prolong the glacials towards 100-ky cycles.

Download & links
Gloria M. Martin-Garcia 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
Gloria M. Martin-Garcia et al.
Gloria M. Martin-Garcia et al.
Viewed
Total article views: 478 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
358 108 12 478 10 15
  • HTML: 358
  • PDF: 108
  • XML: 12
  • Total: 478
  • BibTeX: 10
  • EndNote: 15
Views and downloads (calculated since 21 Mar 2018)
Cumulative views and downloads (calculated since 21 Mar 2018)
Viewed (geographical distribution)
Total article views: 478 (including HTML, PDF, and XML) Thereof 477 with geography defined and 1 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Cited
Saved
No saved metrics found.
Discussed
No discussed metrics found.
Latest update: 25 Sep 2018
Publications Copernicus
Download
Short summary
From 812 to 530 ka, some major oceanographic changes occurred in the N-Atlantic, that were related with the switch of phasing in the Earth's climate system. Since ~ 650 ka, glacials were more prolonged and intense than before. This work explores the relationship between the variation in the N-Atlantic oceanography and the building of ice-sheets that, in turn, worked as positive feedback to prolong the duration of glacials and change the climate system phasing.
From 812 to 530 ka, some major oceanographic changes occurred in the N-Atlantic, that were...
Citation
Share