“…[3] Existing NAO reconstructions based on direct instrumental [Jones et al, 1997] and documentary records of atmospheric pressure [Luterbacher et al, 2002], supplemented by proxy records of rainfall and/or temperature variations from tree rings [Cook et al, 1998] and ice cores [Appenzeller et al, 1998;Barlow, 2001;Vinther et al, 2003] extend pre-instrumental NAO behaviour back to 1429 A.D.; however, considerable disagreement exists between reconstructions [Schmutz et al, 1999]. Recently, NAO variability on longer timescales was inferred from westerly transported fine-grained loess deposits that exhibit increased accumulation during glacial periods [e.g., Vandenberghe et al, 2006].…”