The eruption of fine ash and sulphur dioxide launched into the atmosphere by Iceland’s volcano is likely to produce some spectacular sunsets, a real-life blue moon and some very dirty cars.
As the volcanic clouds are carried large distance by high winds, the sulphur dioxide will react with the atmosphere to form ‘sulfate aerosols’, say scientists.
The ash and these ‘aerosols’ have the effect of scattering the sun’s rays so only longer light waves make it through the atmosphere, which makes the sunsets appear ruby red.
red sky above Heathrow
Red sky at night: The sun sets over Heathrow Airport as an ash cloud from an Icelandic volcano grounded all flights
sun at Heathrow
Golden skies: The sun begins to dip behind the control tower at Heathrow Airport
Weather forecast
Today: Generally cloudy across southern Scotland, Northern Ireland and parts of central and northern England, elsewhere a fine day. A clear, dry night expected.
Tomorrow: Dry with sunny intervals for much of the UK.
Weekend: England, Wales and Northern Ireland mostly dry and often clear, although some rain is likely for many places on Sunday. Scotland generally cloudier with rain at times.
Volcanic ash can also create the appearance of a blue moon, if the particles are the right size (experts say that means one millionth of a metre or a micron).
However, ash thrown up into the atmosphere usually contains a mixture of particles with a wide range of sizes, which tends to scatter blue light so a reddish moon is more likely.
Volcanic eruptions can also have a massive effect on the weather if they are large enough.
Weather forecaster Brendan Jones from MeteoGroup, said: ‘If you look back in history there have been some periods where the weather has been changed by big volcanic eruptions like Mount Tambora and Mount St Helens.
‘They have been proved to lower temperatures. There is so much ash in the atmosphere that it reduces the amount of sunlight getting to the ground.’
‘If the ash remains in our atmosphere for weeks or months it can reduce temperatures slightly but we are talking about fractions of degrees.’
However, experts fear the eruption of Eyjafjallajokull, which has sent this cloud of ash into the sky, could trigger a much larger explosion of nearby Mount Katla.
Katla is described as ‘enormously powerful’, and because it lies under a glacier its eruption would cause a huge glacial outburst flood and could spread its shadow over a much larger area.
The Mount Tambora eruption in 1816 caused such a drop in temperatures that it became known as ‘the year with no summer’
