TY - JOUR T1 - Coupled ocean and atmospheric changes during Greenland stadial 1 in southwestern Europe JF - Quaternary Science Reviews Y1 - 2019 A1 - Naughton, F. A1 - Costas, S. A1 - Gomes, S.D. A1 - Desprat, S. A1 - Rodrigues, T. A1 - Sanchez Goñi, M.F. A1 - Renssen, H. A1 - Trigo, R. A1 - Bronk-Ramsey, C. A1 - Oliveira, D. A1 - Salgueiro, E. A1 - Voelker, A.H.L. A1 - Abrantes, F. KW - Climate variability KW - Greenland stadial KW - Iberian margin KW - Jet stream KW - Moisture availability KW - North Atlantic KW - Paleoclimate KW - Westerlies KW - Younger Dryas Complex AB - 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. VL - 212 UR - https://www.researchgate.net/publication/332292599_Coupled_ocean_and_atmospheric_changes_during_Greenland_stadial_1_in_southwestern_Europe ER - TY - JOUR T1 - A 12,000-yr pollen record off Cape Hatteras — Pollen sources and mechanisms of pollen dispersion JF - Marine Geology Y1 - 2015 A1 - Naughton, F. A1 - Keigwin, L. A1 - Peteet, D. A1 - Costas, S. A1 - Desprat, S. A1 - Oliveira, D. A1 - de Vernal, A. A1 - Voelker, A. A1 - Abrantes, F. AB - Integrating both marine and terrestrial signals from the same sediment core is one of the primary challenges for understanding the role of ocean–atmosphere coupling throughout past climate changes. It is therefore vital to understand how the pollen signal of a given marine record reflects the vegetation changes of the neighboring continent. The comparison between the pollen record of marine core JPC32 (KNR178JPC32) and available terrestrial pollen sequences from eastern North America over the last 12,170 years indicates that the pollen signature off Cape Hatteras gives an integrated image of the regional vegetation encompassing the Pee Dee river, Chesapeake and Delaware hydrographic basins and is reliable in reconstructing the past climate of the adjacent continent. Extremely high quantities of pollen grains included in the marine sediments off Cape Hatteras were transferred from the continent to the sea, at intervals 10,100–8800 cal yr BP, 8300–7500 cal yr BP, 5800–4300 cal yr BP and 2100–730 cal yr BP, during storm events favored by episodes of rapid sea-level rise in the eastern coast of US. In contrast, pollen grains export was reduced during 12,170–10,150 cal yr BP and 4200–2200 cal yr BP, during episodes of intense continental dryness and slow sea level rise episodes or lowstands in the eastern coast of US. The near absence of reworked pollen grains in core JPC32 contrasts with the high quantity of reworked material in nearby but deeper located marine sites, suggesting that the JPC32 record was not affected by the Deep Western Boundary Current (DWBC) since the end of the Younger Dryas and should be considered a key site for studying past climate changes in the western North Atlantic. VL - 367 UR - http://www.sciencedirect.com/science/article/pii/S0025322715001255 JO - A 12,000-yr pollen record off Cape Hatteras — Pollen sources and mechanisms of pollen dispersion ER -