title: A composite annual-resolution stalagmite record of North Atlantic climate over the last three millennia.
abstract: Annually laminated stalagmites can be used to construct a precise chronology, and variations in laminae thickness provide an annual growth-rate record that can be used as a proxy for past climate and environmental change. Here, we present and analyse the first composite speleothem annual growth-rate record based on five stalagmites from the same cave system in northwest Scotland, where precipitation is sensitive to North Atlantic climate variability and the winter North Atlantic Oscillation (NAO). Our 3000-year record confirms persistently low growth-rates, reflective of positive NAO states, during the Medieval Climate Anomaly (MCA). Another persistently low growth period occurring at 290-550 CE coincides with the European Migration Period, and a subsequent period of sustained fast growth-rate (negative NAO) from 600-900 AD provides the climate context for the Viking Age in northern and western Europe.
authors.affiliation: Connected Waters Initiative Research Centre, UNSW Australia, Sydney, NSW 2052, Australia.
authors.forename: Andy
authors.initials: A
authors.lastname: Baker
authors.affiliation: School of Earth Sciences, The University of Melbourne, Melbourne, VIC 3010, Australia.
authors.forename: John
authors.initials: J
authors.lastname: C Hellstrom
authors.affiliation: Connected Waters Initiative Research Centre, UNSW Australia, Sydney, NSW 2052, Australia.
authors.forename: Bryce F J
authors.initials: BF
authors.lastname: Kelly
authors.affiliation: University of Lausanne, Institute of Earth Surface Dynamics (IDYST), UNIL-Mouline, Geopolis, 1015 Lausanne, Switzerland.
authors.forename: Gregoire
authors.initials: G
authors.lastname: Mariethoz
authors.affiliation: Laboratory of Tree-Ring Research, University of Arizona, Tucson AZ 85721, USA.
authors.forename: Valerie
authors.initials: V
authors.lastname: Trouet