Scientists Unraveling Summer Jet Stream Mystery

Lead author of the study, Richard Hall, said: “There is nothing people in the UK like to discuss more than the weather. This is because it can fluctuate so drastically — we can be basking in high temperatures and sunshine one week only to be struck by heavy downpours and strong winds the next.

Edward Hanna, Professor of Climate Change at the University of Sheffield, said: “Working with The Met Office we were able to look at the different factors which may influence the jet stream, which paves the way for improvements in long-term forecasting.”

The findings suggest the latitude of the Atlantic jet stream in summer is influenced by several factors including sea-surface temperatures, solar variability, and the extent of Arctic sea-ice, indicating a potential long-term memory and predictability in the climate system.

Professor Adam Scaife, Head of long range forecasting at the Met Office, said: “We’ve made big inroads into long-range forecasts for winter, but we are still limited to shorter-range weather forecasts in summer. Studies like this help to identify ways to break into the long-range summer forecast problem.”

The study, published in the journal Climate Dynamics was funded by the University of Sheffield’s Project Sunshine now the Grantham Centre for Sustainable Futures, and was conducted in collaboration with the University’s School of Mathematics and Statistics (SOMAS).

Further research will seek to establish the physical mechanisms behind these links and identify the different influences that jet speed and latitude bring to bear on our summer weather.

The other co-authors on the work were Dr Julie Jones, from the University’s Department of Geography, and Professor Robertus von Fay-Siebenburgen, from SOMOS.