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

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 demonstrates that positive NAO phases correspond to wetter but colder regional conditions. These findings suggest that centennial-scale patterns of ice mass balance during the late Holocene were influenced by precipitation variability, in addition to temperature changes. While the sensitivity to precipitation variability may change under a warmer climate, our results underscore the importance of integrating shifts in NAO-driven moisture delivery to accurately assess the future stability of the Greenland Ice Sheet.