Global warming behind cold spell?

PARADOXICALLY, the coldest March the Banner County has seen in almost 60 years could be due to global warming, which some ­scientists believe may have thrown the Jet Stream off course.

 

To say the least of it, last month was chilly, with Met Éireann statistics for Shannon Airport showing it was the coldest March there since 1955.

It was also an exceptionally dry March in Clare, the driest since 1950, with just 28.3mms of precipitation.

The Northern Hemisphere Jet Stream is a band of strong, generally westerly winds concentrated in a relatively narrow and shallow stream in the upper troposphere of the earth and some scientists believe the melting of ice in the Arctic has caused it to move south.

Professor John Sweeney of NUI Maynooth is one of the country’s leading experts on climate change and he said that while some eminent people do hold this view, he believes it’s a bit early to say for sure.
“This research suggests that the lack of sea ice in the Arctic has had an impact on ­changing the jet stream, pushing it much further south, so we have more arctic air masses.

“Certainly, what we’ve seen in the past month or so has been quite unusual in terms of very sustained easterly winds for virtually all of March and very cold temperatures associated with it, coming from Arctic zones.

“It is unusual but it really is only one event and it’s quite hard to be definitive on the basis of one event. I’d say the jury is still out at this point in time.”
He feels the situation in ­Ireland last month may be due to a combination of global warming and other factors.

“You may have a ­combination of the ­natural cycle and the human influence coming into play together here, that’s the most probable conclusion but the mix between the two is hard to determine without a lot more data, I would say.”
Shannon’s experience in March was repeated at weather stations around the country, all of which had ­temperatures far below average.

Sherkin Island had the ­highest mean monthly temperature but this was just six degrees celsius and was still the coldest March there since 1979. It was the coldest March recorded at Dublin Airport since the site opened in 1942 while Claremorris and ­Mullingar also reported their coldest March since opening in 1950.

Thankfully, spring is set to arrive either this weekend or early next week, when temperatures are due to rise noticeably.