Environment

UK winter storms due to extreme air currents in the Arctic

Spread the love

This month has been dubbed by the media as ‘Snowvember’ for a number of years now, and the frosty mornings with snow-capped hills confirm that winter has well and truly arrived.

Most of us reminisce back to the days where we played till the dusk drew in during the summer and made snowmen in the winter. So, a chilly November is nothing to worry about, right?

In the current climate – yes it is. This should be a clear warning sign to us that climate change is here. Official UK statistics from the MET Office show that the temperature across Britain during the winter is indeed declining. More worryingly, however, is the increase of winter storms in Britain; notably the six winter storms of 2014. These were classed as severe and were the fourth most severe winds since 1970.

Sampling melt waters

Arctic angst

Research has shown that global warming has been causing British winters to become colder each year. In concise terms, global warming simply describes the heating of the Earth’s surfaces through the release of greenhouse gases. such as carbon dioxide, methane and nitrous oxide. This heating of the Earth’s surface has led to glaciers and terrestrial ice sheets in regions such as the Arctic to melt and run into waters. Scientists had previously proposed that there was a direct link between the arctic waters and UK weather: the water temperature is causing the UK temperature to plummet during winter seasons.

New research from Sheffield University

However, another school of thought has been researched. Recent studies, conducted by Professor Edward Hanna of Sheffield University, have suggested that the colder temperatures felt in places such as the UK and the US are due to an “increase in the frequency of ridge-trough wave patterns” of northern hemispheric wind patterns (tropospheric polar vortex) which has been found to positively correlate with low-temperatures in the UK and US.

The “ridge-trough” wave patterns refer to the constant curves between the highest and lowest points of the wave. As the waves get shorter or longer, it can affect the world’s climate in different ways.

ridges-and-troughs

Hanna’s study, Nonlinear response of mid-latitude weather to the changing Arctic, explains how these ridge-trough wave patterns are likely to cause colder winters in the UK and other countries in the same latitude. The behaviour of these waves has a strong correlation with the climate experienced in countries worldwide. The study states:

“A wavier jet stream allows cold air from the Arctic to penetrate southwards into mid-latitudes, and ridges transport warm air northward.”

When the wave pattern has less variation between troughs and peaks, (therefore less “wavy”) there is less severity in the winter conditions felt by regions that are in the middle latitudes between the tropics and polar regions, for example, Europe and the US.

Global warming is set to make winters in the UK colder and stormier

The jet stream of these waves seems to move further north in response to warmer temperatures in the Arctic, thus leading to even more climate effects such as more rainfall across the Arctic and also severe droughts, monsoons and stronger hurricanes felt across the globe. One recent example of this is the droughts in Alabama, USA. The National Weather Service in the US, found there was no measurable rainfall in many cities belonging to the state across the duration of October, but Alabama also faced unusually dry months in August and September. This has had a difficult effect on cattle farmers who are unable to plant grass seeds in preparation for next years’ hay harvest, this will also leave farmers  struggling to feed their livestock with quality hay during the winter.

Or will we just keep on heating up…

The two schools of thought about the causes leading to colder winters in Britain; whether it is the waters travelling from the Arctic or the differing jet stream waves, is still being argued. Scientists, such as Tapio Schneider at the California Institute of Technology, has previously dismissed the idea that global warming is leading to colder winters. Tapio’s argument is that the range of temperature fluctuations would decrease as the climate warms in the Arctic.

16-008-nasa-2015recordwarmglobalyearsince1880-20160120

Tapio does point out that “higher latitudes are indeed warming faster than lower ones, which means that the  between the equator and the poles is decreasing.”. He goes on to say:

“Despite lower temperature variance, there will be more extreme warm periods in the future because the Earth is warming.”Schneider modelled his theory and found that temperature variability did indeed decrease regardless of any effects in the Arctic. Schneider also commented that he felt that the waves discussed by Professor Hanna were not to be worried about; he believed that the waves in the jet stream does not change enough to affect our day to day weather.

Schneider modelled his theory and found that temperature variability did indeed decrease regardless of any effects in the Arctic. Schneider also commented that he felt that the waves discussed by Professor Hanna were not to be worried about; he believed that the waves in the jet stream does not change enough to affect our day to day weather.

Schneider modelled his theory and found that temperature variability did indeed decrease regardless of any effects in the Arctic. Schneider also commented that he felt that the waves discussed by Professor Hanna were not to be worried about; he believed that the waves in the jet stream does not change enough to affect our day to day weather.

Hot or cold, global warming is happening to us now

The two arguments, however, are not mutually exclusive, Professor Hanna’s research supports that global warming is still having a huge impact on the Arctic and needs to be reduced. The warming of the Arctic is still a very important factor contributing to global climate change. The warming of the Arctic is contributing to the variability in wave patterns described by Professor Edward Hanna and other researchers. They have concluded that global warming intensifies the effects of the jet stream, and is likely to cause the waves to rise and plummet.

This research has huge implications for how scientists will model climate change in order to make predictions for the future. This is important because accurate predictions can help design adequate safety precautions for any perceived hazards, which will not only be beneficial for the general public but also for businesses and the protection of infrastructure and wildlife.

Hanna’s research highlights the urgent necessity for the global north, including the USA and most of Europe, to reduce its usage of fossil fuels which is still, the leading cause of the human contribution of global warming.

Comments