Persistent influence of the North Atlantic Oscillation on Late Holocene hydroclimate in southwestern Greenland

Abstract

Abstract Understanding how global climate forcing shapes regional hydroclimate on decadal to millennial timescales is critical for predicting the response of continental ice sheets to future warming. Because instrumental observations capture only a short interval, longer-term perspectives require proxy records. Here we present a high-resolution sedimentary record covering the entire Holocene from southwestern Greenland. We show that after the demise of local glaciers in the Early Holocene, the record allows evaluation of millennial to decadal variations in local precipitation. Comparison with North Atlantic Oscillation (NAO) reconstructions and climate model simulations demonstrate that positive NAO phases correspond to wetter but colder regional conditions. These findings indicate that the observed centennial-scale patterns of ice mass balance during the latest Holocene were driven by precipitation rather than temperature. They further suggest that under future climate scenarios, a shift toward more positive and stable NAO phases could promote localized growth of Greenland Ice Sheet margins.