Spatial variability in the European winter precipitationδ18O-NAO relationship: Implications for reconstructing NAO-mode climate variability in the Holocene

This paper investigates the links between precipitation δ 18 O and the North Atlantic Oscillation (NAO) on decadal timescales to identify the optimum locations within Europe at which to compile δ 18 O-based proxy records of past NAO variability. δ 18 O is a commonly used paleoclimate (rainfall and temperature) proxy preserved in natural archives including stalagmites, ice cores, tree rings, and lake sediments. Precipitation δ 18 O data (δ 18 O p ), compiled from Global Network of Isotopes in Precipitation (GNIP) stations in the North Atlantic sector reveal the direction and strength of the δ 18 O p -NAO relationship in mid-latitude, high-latitude, and Mediterranean Europe. The highly significant, positive δ 18 O p -NAO relationship in central Europe is attributed to the strong control of air temperature on δ 18 O p in this region. The δ 18 O p -NAO relationship is strongly negative at high-latitude GNIP sites and weak at Mediterranean sites. Decadal-scale solar irradiance variations correlate with winter δ 18 O p at eight mid-latitude sites.