Unprecedented Early‐Summer Precipitation Over the Greenland in 2024, Driven Primarily by the North Pacific Sea Surface Temperature Anomalies

Abstract Extreme precipitation events exert substantial impacts on the Mass Balance (MB) of the Greenland Ice Sheet (GrIS) and its contribution to global sea level, but elucidating their underlying mechanisms remains challenging. This study utilized in situ observations, ERA5 reanalysis, and GRACE/GRACE‐FO satellite measurements to investigate the unprecedented precipitation during early summer 2024 and its drivers. During June–July 2024, stations in southern and eastern Greenland recorded unprecedented precipitation exceeding two standard deviations above the climatological mean, making it the highest early summer precipitation total since the 1940s. Record‐high North Pacific sea surface temperatures (SSTs) during May–June–July 2024 excited Rossby wave trains, which favored anomalous anticyclonic and cyclonic circulations over Greenland. These circulations enhanced oceanic moisture transport and caused frequent atmospheric river landfalls over southern and southeastern Greenland, which, along with orographic uplift, generated precipitation anomalies equivalent to twice the 1991–2020 climatological mean. As a consequence, the strong precipitation (primarily snowfall) and negative temperature anomalies driven by synoptic circulation led to the smallest summer GrIS mass loss since 2002. Our findings highlight the critical role of North Pacific SST anomalies in driving early summer Greenland precipitation extremes, thereby advancing predictive capability for future extreme events and their implications for GrIS MB under persistent North Pacific warming.