Coupled ocean and atmospheric changes during Greenland stadial 1 in southwestern Europe. (15th May 2019)

• Record Type: Journal Article
• Authors: Naughton, F.; Costas, S.; Gomes, S.D.; Desprat, S.; Rodrigues, T.; Sanchez Goñi, M.F.; Renssen, H.; Trigo, R.; Bronk-Ramsey, C.; Oliveira, D.; Salgueiro, E.; Voelker, A.H.L.; Abrantes, F.
• Is Part Of: Quaternary science reviews. Volume 212(2019)
• Page Start: 108
• Page End: 120
• Publication Date: 2019-05-15
• Subjects: Paleoclimate -- Greenland stadial 1 -- Younger Dryas -- Complex climate variability -- Moisture availability -- Jet stream -- Westerlies -- Iberian margin -- North atlantic; Geology, Stratigraphic -- Quaternary -- Periodicals; Stratigraphie -- Quaternaire -- Périodiques; 551.79
• DOI: 10.1016/j.quascirev.2019.03.033
• Languages: English
• ISSNs: 0277-3791

Abstract

Abstract: Paleoclimate reconstructions suggest that the complex variability within the Greenland stadial 1 (GS-1) over western Europe was governed by coupled ocean and atmospheric changes. However, few works from the North Atlantic mid-latitudes document both the GS-1 onset and its termination, which are often considered as single abrupt transition events. Here, we present a direct comparison between marine (alkenone-based sea surface temperatures) and terrestrial (pollen) data, at very high resolution (28 years mean), from the southwestern Iberian shelf record D13882. Our results reveal a rather complex climatic period with internally changing conditions. The GS-1 onset (GS-1a: 12890-12720 yr BP) is marked by a progressive cooling and drying; GS-1b (12720-12390 yr BP) is the coldest and driest phase; GS-1c (12390-12030 yr BP) is marked by a progressive warming and increase in moisture conditions; GS-1 termination (GS-1d: 12030-11770 yr BP) is marked by rapid switches between cool wet, cold dry and cool wet conditions. Although hydroclimate response was very unsteady throughout the GS-1 and in particular during its termination phase, the persistence of an open temperate and Mediterranean forest in southwestern Iberia during the entire episode suggests that at least some moisture was delivered via the Westerlies. We propose coupled ocean and atmospheric mechanisms to reproduce these scenaria . Changes in the strength of the Atlantic Meridional Overturning Circulation (AMOC) as well as variations in the North Atlantic sea-ice growth have favoured the displacement of the polar jet stream's latitudinal position and contributed to a complex spatial pattern and strength of the Westerlies across western Europe. Highlights: Highlights of the Quaternary Science Reviews paper by Naughton et al.. GS-1 in SW Iberia is a complex climatic period with four main phases. Hydroclimate was very unsteady throughout the GS-1 event and in particular during its termination phase. Ocean and atmospheric changes contributed to a complex spatial pattern of the Westerlies across Western Europe.