Decadal variability of north-eastern Atlantic storminess at the mid-Holocene: New inferences from a record of wind-blown sand, western Denmark

Oceanic versus continental influences over the last 7 kyrs from a mid-shelf record in the northern Bay of Biscay (NE Atlantic)

“…Present-day environmental conditions in northern Europe (i.e., continental climate, as well as sea-surface temperature and salinity changes) are thus strongly impacted by the NAO and associated changes in seasonal precipitation and fluvial discharge regimes (Castaing et al, 1999;Charria et al, 2013;Le Boyer et al, 2013;Tréguer et al, 2014). At the Holocene scale, previous studies have discussed the possible role of the "NAO-like" pattern in westerly storm activity within the north-eastern Atlantic area (van Vliet et al, 2014;Goslin et al, 2018Goslin et al, , 2019Pouzet et al, 2018) as well as in sea-surface and bottom hydrological conditions in the northern (Zumaque et al, 2017;Durand et al, 2018;Mojtahid et al, 2019) and southern BoBy (Garcia et al, 2013;Mojtahid et al, 2013;Mary et al, 2017).…”

“…Eastern North Atlantic Central Water signature Superimposed on this long-term RSL rise, AMOC, and insolation trends, North Atlantic SPG dynamics can be reconstructed at a sub-orbital timescale from marine sediment archives in the northern Atlantic Ocean (e.g., Giraudeau et al, 2010;Solignac et al, 2006Solignac et al, , 2008Zumaque et al, 2017;Ayache et al, 2018;Mojtahid et al, 2019). Millennial timescale events (Bond et al, 1997(Bond et al, , 2001, as well as multi-decadal variability, related to internal modes of atmosphereocean teleconnection such as the "NAO-like" mechanism have exerted a control on the latitudinal position of westerly storm tracks (Sorrel et al, 2012;van Vliet et al, 2014;Goslin et al, 2018Goslin et al, , 2019 and may have strongly impacted Atlantic gyre dynamics throughout the Holocene (Thornalley et al, 2009; Figure 6). Since the CBT-CS11 core was influenced by Eastern North Atlantic Central Waters (ENACW), which were themselves influenced by the NAC, Mojtahid et al (2019) discussed the benthic δ 18 O signal of Cibicides refulgens as a proxy for ENACW waters mainly responding to subpolar rather than subtropical gyre influences.…”

“…The 4-2 ka BP interval of prevalent negative NAO-like conditions is interrupted by the 3.3-2.8 ka BP interval (Bond event 2; Figures 8 and 9) during which persistent positive NAO-like conditions occurred, accompanied by enhanced SPG strength, decreased influence of the warm and salty poleward current (lower winter SST/SSS offshore), and strengthened northern Atlantic westerly storminess (Goslin et al, 2018;Figure 9). Regionally, this latter period (Middle to Late Bronze Age) was characterized by a scarcity of coastal archaeological remains.…”

“…A steady weakening of the SPG was however found throughout the integration of negative NAO modes in a modelling study by Lohmann et al (2009), while positive phases of the NAO strengthened the SPG with poleward advection of NAC waters. This is notably due to the wind-stress implied by northern-located mean westerly storm tracks (e.g., Giraudeau et al, 2010;Goslin et al, 2018). Stronger Loire River discharges from the start of the Late Holocene would therefore represent a conjectural phenomenon of stronger subtropical gyre influence under negative NAO-like modes.…”

“…Map performed using the online EMODnet Portal for Bathymetry (http://www.emodnet-bathymetry.eu/) and adapted from Mojtahid et al (2019). (Goslin et al, 2018), Bond Events as reconstructed through hematite-stained quartz percentages with stacked North Atlantic Ocean cores (Bond et al, 2001) and Total Solar Irradiance (TSI; Steinhilber et al, 2009). Blue horizontal bands represent stacked Eastern European Atlantic Storm Events (Pouzet et al, 2018) while dark blue vertical lines to the right only point to the southern Brittany paleostorminess record (Yeu island; Pouzet et al, 2008).…”