New study couples Arctic sea-ice loss with extreme cold weather

LANZHOU -- A new joint study has provided new scientific evidence for the connection between Arctic sea-ice loss and mid-latitude extreme cold weather events, according to Lanzhou University.

The study reveals the importance of stratospheric feedback in Arctic warming, and is expected to support short-term climate predictions for extreme cold weather, said Tian Wenshou, a professor with the College of Atmospheric Sciences of Lanzhou University.

Over the past decades, the highly-populated Northern Hemispheric mid-latitude was hit by frequent extreme cold events, which caused serious casualties and economic losses. Previous studies have shown that the drastic Arctic sea-ice loss is one of the causes, but their link remains unclear.

Tian's research team joined efforts with overseas researchers to carry out the study. Using reanalysis and model simulations, they demonstrated a new dynamical mechanism responsible for the polar deep warming associated with Arctic sea-ice loss, which has been proven to be a key premise for the Arctic-mid-latitude connection.

The study confirmed the essential role of stratosphere-troposphere coupling for the deep Arctic warming induced by sea-ice loss, which is confirmed by model simulations with stratospheric variability suppressed.

The study results suggest that a considerable part of the observed Arctic mid-to-upper warming is caused by a dynamical response to sea-ice loss, in which stratosphere-troposphere coupling plays a major role.

The results of the study have been published in the journal npj Climate and Atmospheric Science.