BSC contributes to a study clarifying Arctic impacts on European winter

08 February 2022

The paper, led by Met Office researchers, has been published in the journal Nature Communications.

A collaborative international study led by scientists at the Met Office is helping to quell a long-running scientific debate about how the ongoing decline of Arctic sea ice, driven by climate change, can affect the European winters.

Some previous studies - based only on observations - have suggested that the melting Arctic could lead to more severe UK and Western Europe winters by weakening mid-latitude westerly winds. But this relationship cannot be established from observations alone, and previous studies based on climate models were inconclusive, leading to the long-running debate.

To address this issue a large international initiative to run coordinated modelling experiments was launched, including 150 simulations performed at the Barcelona Supercomputing Center (BSC). Two BSC researchers are involved in the study and contributed to the interpretation of the results, Dr. Xavier Levine, who in addition produced the experiments, and Dr. Pablo Ortega, the Climate prediction group coleader.

With 16 different international climate models and more than 3000 individual simulations, the results provide the most robust assessment to date of Arctic impacts on European winters. The paper ‘Robust but weak winter atmospheric circulation response to future Arctic sea ice loss has been published in the journal Nature Communications.

The Met Office’s Dr Doug Smith is the paper’s lead author. He said: “Our study does show a robust weakening of the prevailing westerly winds driven by the continued decline of Arctic sea ice, but this effect is weak when compared with year-to-year variability. In other words Arctic sea ice is unlikely to drive a single severe winter or to outweigh the long term warming from greenhouse gases.”

The study also finds that observed relationships between Arctic sea ice and European winters are weaker when the latest observations are included, reconciling previous differences between observation and modelling studies

The findings maintain consistency with headline results from UKCP18 suite of climate projections that indicates that winters will on average be milder and wetter in future.

The project to harness the results from 16 different climate models has been co-led by Met Office, under the Polar Amplification Model Intercomparison Project (PAMIP) and is endorsed under CMIP6 - the major international climate modelling initiative informing the latest IPCC assessment.