This study investigates the link between wet and warm extremes in Svalbard over the last two millennia and atmospheric blocking regimes over Scandinavia and the Ural Mountains. Using paleoproxies, observations, and a climate model, the researchers demonstrate that rainfall episodes leading to coarse sediment deposition and high calcium levels in Linnévatnet lake are consistently associated with atmospheric blocking events. A unique annually resolved sediment record from Linnévatnet confirms this linkage over the past 2000 years, revealing a millennial-scale decline in Svalbard precipitation ending around the mid-19th century, followed by unprecedented extreme events. The study projects that future Svalbard floods will intensify during Scandinavian and Ural blocking episodes due to continued warming and sea ice recession.

Francois Lapointe, Ambarish V. Karmalkar, Raymond S. Bradley, Michael J. Retelle, Feng Wang