The ‘Beast from the East’ and the freakishly warm Arctic temperatures are no coincidence

Frozen: the Kennet & Avon canal, Bath. Image: Getty.

During the past few weeks, bitterly cold weather has engulfed the UK and most of Northern Europe. At the same time, temperatures in the high Arctic have been 10 to 20°C above normal – although still generally below freezing.

The co-occurence of these two opposite extremes is no random coincidence. A quick climate rewind reveals how an unusual disturbance in the tropics more than a month ago sent out shock-waves thousands of kilometres in all directions, causing extreme weather events – not only in Europe and the Arctic, but in the southern hemisphere too.

The outbreak of cold weather across the UK was publicly forecast at least two weeks in advance. In early February, meteorologists noticed a large-scale weather event developing 30km high in the Arctic stratosphere, whose effects on our less lofty weather systems are well understood.

The strong westerly winds, known as the Polar Vortex, that normally circle the Arctic at this altitude had begun to weaken and change direction. Extremely cold arctic air – usually entrapped by this 360° barrier – was able to spill out to lower latitudes, flooding across Siberia.

Meteorologists refer to this type of event as a Sudden Stratospheric Warming (SSW) because the air in the stratosphere above the North Pole appears to warm rapidly. In fact, the cold air isn’t itself warming up so much as flooding south and being replaced by warmer air from further south.

Current air temperatures in the Arctic are much higher than recent historical averages. Image: Zachary Labe.

Changes to wind directions and temperatures 30km above the ground initially went unnoticed to those on the ground – both in Europe and in the Arctic. But over a period of several weeks, the influence of this weather event moved gradually downwards through the lower region of the atmosphere, eventually changing weather patterns near the surface.

One such change was the development of high pressure across Scandinavia, which generated easterly winds across the whole of Northern Europe, pulling cold air from Siberia directly over the UK. Out over the Atlantic Ocean the same area of high pressure resulted in southerly winds allowing warm air from the Atlantic to move northwards into the Arctic basin. Research shows that these weather shifts tend to be fairly persistent once they do occur – hence the unusual length of the cold spell we’re experiencing, and the warmth in the Arctic.

But what caused the stratospheric Arctic warming event to happen in the first place? For this we need to look thousands of kilometres away to the atmosphere above the tropical West Pacific Ocean. In late January, a vast area of thunderstorms, as large and strong as have ever been recorded, were disturbing the atmosphere across this region. The effect of these storms was equivalent to the dropping of a large boulder into a pond – they caused waves of alternating high and low pressure to spread through the atmosphere, particularly into the northern hemisphere. It was these waves bumping into the vortex of winds around the North Pole that caused the Sudden Stratospheric Warming event in early February.

The very same area of thunderstorms across the tropical Pacific acted as the birthplace for the less-reported Cyclone Gita, which tracked through the South Pacific, causing damage in Tonga and Samoa and even leading to unseasonably stormy weather across New Zealand at the end of their summer.


The near simultaneous occurrence of all of these extreme weather events is a perfect meteorological illustration of the butterfly effect. While we usually talk about weather in local and regional terms, the atmosphere is one continuous fluid expanse. Disturbances in one region are bound to have consequences to the weather in other parts of the world – and when they are severe the shock-waves can be immense.

Many have linked the severity of these events with climate change. But, particularly for this event, its important for us meteorologists to exercise caution. The occurrence of this particular stratospheric warming event is not itself a consequence of climate change, as one extreme weather event on its own does not tell us anything about long-term trends in the Earth’s climate.

What’s important is to look at how often these events occur – and how severe they are when they do. However, the series of events that lead to cold weather over Europe are complex and have only been well understood for the past 20 years or so. Without a few more decades of data, it is difficult to say whether either the stratospheric warming or the intense tropical storms are part of a pattern that falls outside of what we would normally expect – though limited research does already suggest that Stratospheric Sudden Warming events are becoming more frequent.

The ConversationFor other extreme weather events, the story is clearer – evidence increasingly suggests that hurricanes, storms and wildfires are becoming both more frequent and more severe than they once were. Time will tell if its the same story for Stratospheric Sudden Warming and tropical disturbances.

Evidence from these recent temperature extremes will certainly help researchers to understand this question. But if we do what we can to minimise the damaging impacts of climate change, we may never need to find out.

Peter Inness, Lecturer in Meteorology, University of Reading.

This article was originally published on The Conversation. Read the original article.

 
 
 
 

High streets and shopping malls face a ‘domino effect’ from major store closures

Another one bites the dust: House of Fraser plans to close the majority of its stores. Image: Getty.

Traditional retail is in the centre of a storm – and British department store chain House of Fraser is the latest to succumb to the tempest. The company plans to close 31 of its 59 shops – including its flagship store in Oxford Street, London – by the beginning of 2019. The closures come as part of a company voluntary arrangement, which is an insolvency deal designed to keep the chain running while it renegotiates terms with landlords. The deal will be voted on by creditors within the month.

Meanwhile in the US, the world’s largest retail market, Sears has just announced that it will be closing more than 70 of its stores in the near future.

This trend of major retailers closing multiple outlets exists in several Western countries – and its magnitude seems to be unrelated to the fundamentals of the economy. The US, for example, has recently experienced a clear decoupling of store closures from overall economic growth. While the US economy grew a healthy 2.3 per cent in 2017, the year ended with a record number of store closings, nearly 9,000 while 50 major chains filed for bankruptcy.

Most analysts and industry experts agree that this is largely due to the growth of e-commerce – and this is not expected to diminish anytime soon. A further 12,000 stores are expected to close in the US before the end of 2018. Similar trends are being seen in markets such as the UK and Canada.

Pushing down profits

Perhaps the most obvious impact of store closures is on the revenues and profitability of established brick-and-mortar retailers, with bankruptcies in the US up by nearly a third in 2017. The cost to investors in the retail sector has been severe – stocks of firms such as Sears have lost upwards of 90 per cent of their market value in the last ten years. By contrast, Amazon’s stock price is up over 2,000 per cent in the same period – more than 49,000 per cent when considering the last 20 years. This is a trend that the market does not expect to change, as the ratio of price to earnings for Amazon stands at ten times that of the best brick-and-mortar retailers.

Although unemployment levels reached a 17-year low in 2017, the retail sector in the US shed a net 66,500 jobs. Landlords are losing longstanding tenants. The expectation is that roughly 25 per cent of shopping malls in the US are at high risk of closing one of their anchor tenants such as a Macy’s, which could set off a series of store closures and challenge the very viability of the mall. One out of every five malls is expected to close by 2022 – a prospect which has put downward pressure on retail real estate prices and on the finances of the firms that own and manage these venues.

In the UK, high streets are struggling through similar issues. And given that high streets have historically been the heart of any UK town or city, there appears to be a fundamental need for businesses and local councils to adapt to the radical changes affecting the retail sector to preserve their high streets’ vitality and financial viability.


The costs to society

While attention is focused on the direct impacts on company finances, employment and landlord rents, store closures can set off a “domino effect” on local governments and businesses, which come at a significant cost to society. For instance, closures can have a knock-on effect for nearby businesses – when large stores close, the foot traffic to neighbouring establishments is also reduced, which endangers the viability of other local businesses. For instance, Starbucks has recently announced plans to close all its 379 Teavana stores. Primarily located inside shopping malls, they have harshly suffered from declining mall traffic in recent years.

Store closures can also spell trouble for local authorities. When retailers and neighbouring businesses close, they reduce the taxable revenue base that many municipalities depend on in order to fund local services. Add to this the reduction in property taxes stemming from bankrupt landlords and the effect on municipal funding can be substantial. Unfortunately, until e-commerce tax laws are adapted, municipalities will continue to face financial challenges as more and more stores close.

It’s not just local councils, but local development which suffers when stores close. For decades, many cities in the US and the UK, for exmaple Detroit and Liverpool, have heavily invested in efforts to rejuvenate their urban cores after years of decay in the 1970s and 1980s. Bringing shops, bars and other businesses back to once derelict areas has been key to this redevelopment. But today, with businesses closing, cities could once again face the prospect of seeing their efforts unravel as their key urban areas become less attractive and populations move elsewhere.

Commercial ecosystems featuring everything from large chain stores to small independent businesses are fragile and sensitive to change. When a store closes it doesn’t just affect employees or shareholders – it can have widespread and lasting impacts on the local community, and beyond. Controlling this “domino effect” is going to be a major challenge for local governments and businesses for years to come.

Omar Toulan, Professor in Strategy and International Management, IMD Business School and Niccolò Pisani, Assistant Professor of International Management, University of Amsterdam.

This article was originally published on The Conversation. Read the original article.