title: Annually resolved North Atlantic marine climate over the last millennium.
abstract: Owing to the lack of absolutely dated oceanographic information before the modern instrumental period, there is currently significant debate as to the role played by North Atlantic Ocean dynamics in previous climate transitions (for example, Medieval Climate Anomaly-Little Ice Age, MCA-LIA). Here we present analyses of a millennial-length, annually resolved and absolutely dated marine δ18O archive. We interpret our record of oxygen isotope ratios from the shells of the long-lived marine bivalve Arctica islandica (δ18O-shell), from the North Icelandic shelf, in relation to seawater density variability and demonstrate that solar and volcanic forcing coupled with ocean circulation dynamics are key drivers of climate variability over the last millennium. During the pre-industrial period (AD 1000-1800) variability in the sub-polar North Atlantic leads changes in Northern Hemisphere surface air temperatures at multi-decadal timescales, indicating that North Atlantic Ocean dynamics played an active role in modulating the response of the atmosphere to solar and volcanic forcing.
authors.affiliation: School of Earth and Ocean Sciences, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK.
authors.forename: D J
authors.initials: DJ
authors.lastname: Reynolds
authors.affiliation: School of Ocean Sciences, College of Natural Science, Bangor University, Menai Bridge, Anglesey LL59 5AB, UK.
authors.forename: J D
authors.initials: JD
authors.lastname: Scourse
authors.affiliation: Department of Geography, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4RJ, UK.
authors.forename: P R
authors.initials: PR
authors.lastname: Halloran
authors.affiliation: School of Earth and Ocean Sciences, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK.
authors.forename: A J
authors.initials: AJ
authors.lastname: Nederbragt
authors.affiliation: Department of Geological and Atmospheric Sciences, Iowa State University, Ames, Iowa 50011-3212, USA.
authors.forename: A D
authors.initials: AD
authors.lastname: Wanamaker
authors.affiliation: School of Ocean Sciences, College of Natural Science, Bangor University, Menai Bridge, Anglesey LL59 5AB, UK.
authors.forename: P G
authors.initials: PG
authors.lastname: Butler
authors.affiliation: School of Ocean Sciences, College of Natural Science, Bangor University, Menai Bridge, Anglesey LL59 5AB, UK.
authors.forename: C A
authors.initials: CA
authors.lastname: Richardson
authors.affiliation: Aarhus AMS Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark.
authors.forename: J
authors.initials: J
authors.lastname: Heinemeier
authors.affiliation: Institute of Earth Sciences, University of Iceland, Askja, Sturlugata 7, IS-101 Reykjavík, Iceland.
authors.forename: J
authors.initials: J
authors.lastname: Eiríksson
authors.affiliation: Department of Geoscience, Aarhus University, Høegh-Guldbergs Gade 2, DK-8000 Aarhus C, Denmark.
authors.forename: K L
authors.initials: KL
authors.lastname: Knudsen
authors.affiliation: School of Earth and Ocean Sciences, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK.
authors.forename: I R
authors.initials: IR
authors.lastname: Hall