University of Southampton researchers showed that the winter jet stream over the North Atlantic and Eurasia has increased its average speed by 8% to 132 miles per hour. The jet stream has brought storms Dudley, Eunice and Franklin to the UK. It has also moved northwards by up to 330 kilometers. The study relates to the 141-year period from 1871–2011.
Jet streams are fast bands of air. It flows around the globe at about ten thousand meters above Earth’s surface. It has a significant influence on storm activity and temperature patterns across the northern hemisphere. This can also impact the weather through strong winds and flooding events. This is the longest regional study of the northern hemisphere jet stream. The trends observed are potential indicators of climate change.
The study has been published in Climate Dynamics. It has provided a comparison of the Northern Hemisphere jet stream across oceans and continents. Scientists found that jet stream trends vary on a regional and seasonal basis. Between 1871 and 2011 the average winter movement in jet stream latitude over the North Atlantic was from 44° to 47° north with a 10 miles per hour increase in speed. But no increases were observed over the North Pacific.
The study highlighted that northern hemisphere jet variability and trends differ on a regional basis across the North Atlantic, North Pacific, Eurasia and North America. It is important for making climate predictions. It is also important in developing plans to combat climate change.
The study is the result of a statistical analysis of the 250mb jet stream. Scientists have used the Twentieth Century Reanalysis dataset for their research.
