Jan 1, 2018

UK's recent extreme weather linked to Arctic warming

United Kingdom
Emily Beament
Belfast Telegraph
The shot of Earth from Apollo 8. Image: Belfast Telegraph
The shot of Earth from Apollo 8. Image: Belfast Telegraph

The UK has been hit by a number of extreme weather events in the past decade, including heavy rain in summer 2007 and 2012, the record wet and stormy winter of 2013/14 and cold and snowy winters in 2009/10 and 2010/11.

Researchers compared data of recent UK extremes with the position of the North Atlantic jet stream - a giant current of air - using an index which indicates shifts north and south.

The exceptional wet summers, snowy cold snaps and mild stormy winters all corresponded with pronounced negative or positive spikes in readings of the index, showing more extreme north and southward movements of the jet stream.

The researchers also linked the jet stream's altered path - its increasing 'waviness' - with a rise in summer months of areas of high pressure remaining largely stationary over Greenland, distorting the path of storms across the North Atlantic.

While many factors influence the weather, the researchers from the University of Lincoln and the National Oceanographic and Atmospheric Administration (NOAA) in the US said global warming could be one of the causes.

The strength and path of the North Atlantic jet stream and the high pressure in Greenland appear to be influenced by increasing temperatures in the Arctic, which has been warming much faster than the global average in the past two decades.

Professor Edward Hanna, from the University of Lincoln's School of Geography, said: "Arctic warming may be driving recent North Atlantic atmospheric circulation changes that are linked to some of the most extreme weather events in the UK over the past decade."

The study was published in Weather, the magazine of the Royal Meteorological Society.