Monday 17 December 2012, 12:48
We may have to get used to wet summers like we've seen recently across the UK, according Dr Edward Hanna from Sheffield University in an interview which you can see on Inside Out and Look North tonight.
According to Dr Hanna and an international team of scientists, melting summer Arctic ice may be weakening the jet stream, leading it to meander and become slow moving.
This effectively means that weather patterns become locked in for long periods of time.
The jet stream is a ribbon of strong winds high up in the atmosphere, a result of the temperature contrast between northern latitudes towards the Arctic, and latitudes further south.
Because the Arctic is warming faster than any other region on earth, this temperature contrast is getting weaker, leading to a less powerful jet stream in summer.
Crucial to the UK and Northwest Europe is Greenland, a huge mountanous land-mass which can act as a barrier to the jet stream.
If the jet stream is weaker than normal, two things can happen.
It can either split, with one arm going northeastwards, with the other travelling southeastwards towards the UK.
Or the whole jet stream can be deflected southeastwards towards the UK.
The result in both cases would be wet, cool, unsettled conditions as we have seen since 2007.
Not every summer is likely to be poor.
The slow-moving jet stream may become positioned to the north of us, leading to warm settled conditions.
But because of our position relative to Greenland, these summers are likely to be the exception to the rule.
Dr Hanna says if this theory is correct and summer Arctic ice melt continues, there is also likely to be a higher risk of extreme rainfall events such as we have experienced in 2007 and again this year.
The research, which was carried out jointly by experts from NOAA (National Oceanic and Atmospheric Administration), Rutgers University, University of Washington, and the University of Sheffield, was published in the journal Geophysical Research Letters.
You can see more on this on BBC Look North from Leeds, on BBC1 at 6.30pm, (Sky channel 956, Freesat 966) or on BBC1's Inside Out at 7.30pm (Sky 956 & 957, Freesat 966 & 967).
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Thursday 13 December 2012, 13:40
Thursday 3 January 2013, 11:27