A bizarre phenomenon was spotted
over Britain this week which looked like someone had punched a hole in the sky.
However, experts at the Met Office say the hole was in fact a holepunch or fallstreak cloud.
This atmospheric phenomenon is believed to be caused by a combination of both mother nature and man.
Scientific opinion as to what finally causes the ice to form and begin to crystallize in the atmosphere has only solidified in recent years as meteorologists have become more certain that airplanes flying through the clouds start the process.
Air passing along propeller blades
or wings expands and cools rapidly.
The ice crystals begin to form and after the plane is long gone - the crystals can still be seen where they've dropped down below the cloud.
What's left above the drifting ice particles is a round hole in the cloud that can sometimes be very large.
If the sun catches the particles
at just the right angle, another phenomenon called a sun dog can form as a
bright patch of colored light hovering in the sky.
This photograph was taken by Marc Eilbeck and posted on Twitter.
Nicole Maxey, from the Met Office, said: 'This is a holepunch or fallstreak cloud.
'It forms when part of the cloud layer forms ice crystals which are large enough to fall.
'This happens in clouds of supercooled water droplets – water that is below 0°C but not yet frozen.
'These water droplets need a tiny particle, a nucleus, to freeze or to be cooled below -40°C.
'Aircraft punching through this cloud layer can cause air to expand and cool as it passes over the aircraft wings or propeller.
'This change in temperature can be enough to encourage the supercooled droplets to freeze and fall from the cloud layer in this distinctive pattern.'
However, experts at the Met Office say the hole was in fact a holepunch or fallstreak cloud.
This atmospheric phenomenon is believed to be caused by a combination of both mother nature and man.
Experts say this pattern was probably
caused by ice crystals forming round an aeroplane
For the fallstreak hole to begin,
cirrocumulus or altocumulus must contain super-cooled water which cannot freeze
without a tiny particle to first cling to.Scientific opinion as to what finally causes the ice to form and begin to crystallize in the atmosphere has only solidified in recent years as meteorologists have become more certain that airplanes flying through the clouds start the process.
The ice crystals begin to form and after the plane is long gone - the crystals can still be seen where they've dropped down below the cloud.
What's left above the drifting ice particles is a round hole in the cloud that can sometimes be very large.
This photograph was taken by Marc Eilbeck and posted on Twitter.
Nicole Maxey, from the Met Office, said: 'This is a holepunch or fallstreak cloud.
'It forms when part of the cloud layer forms ice crystals which are large enough to fall.
'This happens in clouds of supercooled water droplets – water that is below 0°C but not yet frozen.
'These water droplets need a tiny particle, a nucleus, to freeze or to be cooled below -40°C.
'Aircraft punching through this cloud layer can cause air to expand and cool as it passes over the aircraft wings or propeller.
'This change in temperature can be enough to encourage the supercooled droplets to freeze and fall from the cloud layer in this distinctive pattern.'
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