Quantifying the influence of Barents-Kara Sea ice loss on Ural blocking

Arctic amplification has been linked to significant changes in mid-latitude weather patterns, including the increasing frequency of extreme weather events. Understanding the mechanisms behind these connections remains a critical challenge in climate science, particularly as the Arctic climate experiences rapid changes. This project investigates the causal pathways linking Arctic amplification to mid-latitude dynamics, with a specific focus on the two-way interactions between Barents-Kara Sea ice loss and winter blocking in the Ural Mountains region, and their link to cold extremes in Eurasia. For this we compute two types of blocking diagnostics (one anomaly based index, and one reversal index) and quantify their changes over time in association with sea ice loss in the Barents and Kara region. Given the limited sample size of the observational record and the large internal climate variability, we not only use reanalysis data but also large-ensemble climate model simulations. Moreover, to address these complex interactions in the presence of potential confounding factors such as ENSO, the project employs causal inference theory within a causal network framework. By disentangling and quantifying sea ice-blocking interactions, the study aims to elucidate critical knowledge gaps in understanding Arctic-midlatitude linkages and to enhance the predictability of future extreme weather events under a warming climate.