The science behind Europe’s Siberian chill this week

Nice out. The A48 in the snow. Image: Getty.

The so-called “Beast from the East” arrived in the UK this week, bringing unusually cold weather – about 7°C colder than the historical average for this time of year. Wind chill is making temperatures feel particularly arctic.

So how did the Siberian gusts come to arrive on Europe’s doorstep?

The movement of air across the globe, and the weather it brings with it, is governed by three major influences: gravity, the sun, and something called the Coriolis effect. The influence of gravity is simple, constantly pulling air towards the Earth’s surface.

The rise and fall of the sun dictates whether the air stays there. During the day, radiation from the sun heats the Earth, warming air directly above the surface and causing it to rise, leaving behind a region of low pressure (a low density of air particles). As the air rises, it cools and spreads outwards.

This mass of air, now denser than the air below it, sinks back down under the force of gravity, and naturally flows back towards the lower pressure region of air, creating a cycle of air circulation. These circulating patterns of wind exist on an intercontinental scale, transporting heat all the way from the tropics to the poles.

However, thanks to the Coriolis effect – the deflection of objects moving in a straight path due to the Earth’s rotation – the winds do not travel directly north or south. To illustrate this effect, imagine a spinning top. Parts of the spinning top closer to the spindle rotate at slower speeds than parts further away, as they have less distance to travel to complete a full circle. Similarly, the equator has to travel much faster than the poles do as the Earth rotates. As air travels north from the equator, its extra momentum compared to the slower rotating land that it is moving over makes it curve across to the east, while air travelling to the south pole curves westward.

In the northern hemisphere, this interaction between the Coriolis effect and the circulation systems produces the northern polar jet stream: high altitude currents of air blowing eastwards at hundreds of miles per hour, moving weather systems around the globe. This causes the UK’s prevailing westerly and south-westerly winds, which usually draw weather systems in from the relatively warm Atlantic and shield us from colder air masses to the east.

The shape of the jet streams is not rigid – it follows a meandering path, much like a slithering snake. Occasionally, the jet stream path can become so twisted that it folds back upon itself, reversing the direction of the prevailing wind, and drawing in cold air from the east.


This is exactly what just happened. In the last couple of days, the bitterly cold front combined with water vapour in the air to carpet the country in a blanket of brilliant white.

As the warmth of the sun disappears each night, the cold can feel all the more biting. But in the absence of the sun’s heat, the smaller difference in temperature between air near the ground and higher up makes air circulate more slowly. This often creates calmer conditions that might just provide a brief respite from the extra chill of the wind. For this same reason, air passengers generally experience smoother flying conditions when flying at night.

If you live in the city however, your experience of the “beast” can vary wildly from place to place. Cities continue to produce heat at night, generating their own microclimates. This man-made heat keeps air moving, and warms city dwellers up more than those in rural areas. At the same time, the ordered formation of buildings in cities creates strong wind corridors that are certainly best avoided at times like these.

Wherever you are experiencing this freezing weather, you can at least be thankful that you are here on Earth. Wind circulation patterns on other planets produce far more extreme weather than we will ever experience. Visitors to Venus, for example, would experience some serious turbulence when approaching landing, as the 500°C difference between surface and cloud generates extreme air circulation.

The ConversationHowever, if you were lucky enough to touch down and survive the experience of the crushing pressure found on Venus’ surface, you would feel nothing more than a gentle breeze, thanks to the planet’s very slow rotation, weak Coriolis effect, and dense air. You might want to seek shelter though – at close to 460°C, suddenly a cold chill doesn’t seem so bad.

Gareth Dorrian, Post Doctoral Research Associate in Space Science, Nottingham Trent University and Ian Whittaker, Lecturer, Nottingham Trent University.

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

 
 
 
 

Here are my five favourite London council estates

The Dunboyne Road estate. Image: Steve Cadman/Wikimedia Commons.

The author is a Labour member of the London Assembly. In the name of impartiality, CityMetric would like to extend the invitation to write similar columns to representatives of other political parties.

From successful post-war efforts to move families out of slums and into modern homes, to today’s efforts to construct a new generation of social housing, there’s much to be celebrated in London’s precious council housing stock.

This year we celebrate the centenary of the Addison Act, which established a national building programme with government funding for the first time. So here – in no particular order – are my top five London estates:

1. Dunboyne Road

In 1965, the newly established London Borough of Camden was bold and radical when it came to public housing. Their architect’s department boasted 98 staff, led by Sydney Cook. The Grade II listed Dunboyne Road (pictured above) was Britain’s first high-density, low-rise estate. Designed in the late 1960s and completed in 1977, it was the first major work by architect Neave Brown.

Its concrete construction and geometric layout are eye-catchingly modernist, but the 71 flats and maisonettes fit neatly into their surroundings; a reimagining of the classic London street for the 1960s. Each has a private terrace and own entrance onto the central pedestrian walkway and communal gardens, with stepped levels and dual-aspect windows creating light throughout.

Neave Brown himself lived on the estate in the final years of his life remarking, “Who am I to say, but it’s beautiful”.

2. Lilington Gardens

Located just off Vauxhall Bridge Road, the fourteen blocks at Lilington Gardens were built between 1964 and 1972. Between three and eight storeys each, it was again a rejection of the tower blocks which dominated the era, showing that mid-rise housing could provide both beauty and density.

Image: Ewan Munro/Wikimedia Commons.

At a time when Westminster could be proud of the quality of its housing, John Darbourne and Geoffrey Darke won a competition to design the new estate. The result was something special, eschewing modernist forms for something more rugged and layered. The layout allows for secluded green spaces, while the red brick cladding echoes the neighbouring Victorian church of St James the Less. Like all good estates, it included a pub – the Grade II*-listed Pimlico Tram (now The Cask). It was included not as an afterthought, but an integral part of the estate’s design.

3. Ossulston Estate

By the early 1950s, the London County Council’s architect’s department was the biggest in the world, building housing on a huge scale in addition to showp iece projects such as the Southbank Centre.

Though their suburban estates – Downham in Bromley, and Becontree in Barking and Dagenham – were pioneering examples of low-rise of modernity in metroland, these efforts did not always suit the needs of poor city dwellers who weren’t able to move further out. The Ossulton Estate, however, built between 1927 and 1931 on the site of a Somerstown slum and located between Euston and St Pancras stations, did exactly that.

Image: Stephen McKay/Wikimedia Commons.

Chief architect George Topham Forrest’s work was inspired by visits to ‘Red’ Vienna and Ossulston bears distinct similarities to Karl Marx-Hof, which was constructed at the same time. While the roofs and windows have traditional elements, the overall aesthetic is a modernist classic. Like many estates in post-war years, it suffered from neglect and a lack of investment, but following a £6m improvement programme by Camden Council in 2004, the Ossulston is now back to its brilliant best.

4. Alton Estate

Roehampton’s Alton Estate, completed in 1959, was designed by a team led by Rosemary Stjernstedt – the first woman to serve as a senior public sector architect in Britain.

The two parts of the estate – East and West – are the crown jewels of British post-war council housing. Alton West was Le Corbusier in Albion: six ultra-modernist blocks modelled on the Unité d’habitation in Marseille, set among the landscape inherited from the Georgian Mount Clare house. Alton East was a softer, Scandinavian-inspired design of the “new Brutalists” in the LCC.

Image: Stevekeiretsu/Wikimedia Commons.

Rising above the trees to the north east of Richmond Park, the Alton Estate stands testament to the visionary idealism of post-war council housebuilding. On its completion, visitors flocked from across the globe, with American critic G.E. Kidder Smith calling it “probably the finest low-cost housing development in the world”.

Sadly, Alton West however is now at risk from ‘regeneration’ proposals which would see 288 existing homes lost. While council estates should not be fetishised, with investment, improvement and expansion encouraged, any change must be done sensitively and with residents’ backing. I hope that Wandsworth Council and Redrow will follow the mayor’s Good Practice for Estate Regeneration and hold a ballot before plans go ahead, and that if they do, they build on Rosemary Stjernstedt’s legacy.

5. King’s Crescent

When it comes to regeneration Hackney Council have taken an altogether different approach to Wandsworth.

Located on Green Lanes opposite the magnificent Clissold Park, King’s Crescent’s route to a successful and well-supported regeneration project hasn’t always been an easy one. The early 1970s estate was blighted by poor construction, navigability issues and an ill-fated partial demolition in 2000 which turned much of the landscape into hoardings and rubble. But thanks to a step-change in resident engagement and a transformation programme funded by Hackney Council, by 2023 it will be host to 765 new and refurbished homes.

Image: David Holt/Wikimedia Commons.

In the era of government-imposed cuts to local authority budgets, councils have to be pragmatic about funding choices and the new King’s Crescent does include homes for private sale. This is understandably a source of some consternation, but it’s also the source of funding which has made the regeneration possible. Hackney has ensured that more than 50 per cent of the new homes are genuinely affordable, with 97 brand new council homes for social rent.

The new developments have greatly enhanced the area, using both new build and renovation to stitch the estate better into its Victorian surroundings. Existing homes have been retrofitted with balconies, while disused garage space has been repurposed for modern flats. Hackney have clearly thought carefully about character and open spaces, as well as ceiling heights, windows and internal storage.

It is an exceptional project – one of a growing number of new schemes now being spearheaded by ambitious councils across the capital. In 2018-19, the Mayor of London funded the start of 1,916 new council homes – the highest figure since 1984-85.


…what about the Barbican?

On the fiftieth anniversary of its opening, it would be remiss not the mention the Barbican. It’s a brutalist masterpiece and a fantastic feat of post-war planning and design. The location and design are clearly outstanding, but it’s the bright and modern interiors which are truly to die for.

So why is it not on the list? Although it was built by the City of London Corporation, not one of the flats was ever available at a social rent. The properties were built to let at market rents to workers in the City, who later found themselves in the fortunate position of being able to snap them up under the Right to Buy – still the fate of far too many of London’s vital social homes.

Tom Copley is a Labour member of the London Assembly.