Librarian Ian Pattinson took a photo of some clouds above St Albans, Hertfordshire.
usually, there'll be nothing remarkable about that, except these were mysterious "bubble" clouds, or mammatus clouds.
How they form is a mystery...
Stunning pictures of 'bubble' clouds in the menacing skies above Britain
By MICHAEL HANLON, Science Editor
21st August 2008
Daily Mail
Dark, brooding and menacing. This apparition, which materialised over the skies of Hertfordshire, looks like an expensive special effect from a horror movie.
The strange globular clouds, which resemble drops of oil poured into a murky pond, appear to herald the appearance of an alien spacecraft, here to cause havoc.
In fact, this picture shows a rare but perfectly natural (and perfectly harmless, provided you do not try to fly through it in light aircraft) meteorological phenomenon known as a mammatus cloud.
Enlarge
Freak: The weird weather is called a mammatus from the Latin word for breast
Named after the Latin for breast, mammatus clouds are associated with the powerful storms which can occur in the summer, and are a sign of the massive quantities of water vapour that are held in the languid summer air.
Mammatus lobes can form under several types of cloud but this particular spectacle appears to be associated with the cumulonimbus thunderclouds which caused the storms that afflicted much of southern England last week.
How they form is something of a mystery.
Enlarge
Foreboding: Ian Pattison photographed the outside his home in St Albans, Herts
Clouds in general consist of water droplets, ice crystals or a mixture of both, and the shapes of the various cloud forms are caused by a number of factors such as temperature, the ratio of water and ice, the altitude of the cloud and the windspeeds within it.
The exact forms are also governed by a complex interplay of wind, rising and falling air, and changes in humidity and density.
But while most clouds have wispy edges, mammatus lobes, which are usually stable for only a few minutes-have unusually sharp and well-defined boundaries. Each lobe can be up to a mile in diameter.
They are also nearly opaque, making them look far more tangible than a mass of droplets and ice flecks.
This picture was taken by Ian Pattison, 31, an assistant librarian, outside his home in St Albans last week. He said: 'I got a new phone last week and when I saw this amazing sky, I just grabbed it and started snapping.'
Strange clouds such as these are probably behind one of the most perplexing phenomena of modern times - the UFO sighting.
When agglomerations of condensed water vapour become concentrated-enough, and the light strikes them in the right way, some low-level clouds can give the appearance of being solid objects.
But there was nothing alien over the skies of St Albans last week. Just a lot of very British rain and a sheet of spectacular, if rather unsettling, water droplets in the sky. o you know your cirrus from your cumulo
1. Is it Altocumulus, Altostratus or Cumulonimbus?
2. Is it Cirrostratus, Cirrocumulus or Cirrus?
3. Is it Stratus, Stratocumulus or Nimbostratus?
dailymail.co.uk
usually, there'll be nothing remarkable about that, except these were mysterious "bubble" clouds, or mammatus clouds.
How they form is a mystery...
Stunning pictures of 'bubble' clouds in the menacing skies above Britain
By MICHAEL HANLON, Science Editor
21st August 2008
Daily Mail
Dark, brooding and menacing. This apparition, which materialised over the skies of Hertfordshire, looks like an expensive special effect from a horror movie.
The strange globular clouds, which resemble drops of oil poured into a murky pond, appear to herald the appearance of an alien spacecraft, here to cause havoc.
In fact, this picture shows a rare but perfectly natural (and perfectly harmless, provided you do not try to fly through it in light aircraft) meteorological phenomenon known as a mammatus cloud.
Enlarge
Freak: The weird weather is called a mammatus from the Latin word for breast
Named after the Latin for breast, mammatus clouds are associated with the powerful storms which can occur in the summer, and are a sign of the massive quantities of water vapour that are held in the languid summer air.
Mammatus lobes can form under several types of cloud but this particular spectacle appears to be associated with the cumulonimbus thunderclouds which caused the storms that afflicted much of southern England last week.
How they form is something of a mystery.
Enlarge
Foreboding: Ian Pattison photographed the outside his home in St Albans, Herts
Clouds in general consist of water droplets, ice crystals or a mixture of both, and the shapes of the various cloud forms are caused by a number of factors such as temperature, the ratio of water and ice, the altitude of the cloud and the windspeeds within it.
The exact forms are also governed by a complex interplay of wind, rising and falling air, and changes in humidity and density.
But while most clouds have wispy edges, mammatus lobes, which are usually stable for only a few minutes-have unusually sharp and well-defined boundaries. Each lobe can be up to a mile in diameter.
They are also nearly opaque, making them look far more tangible than a mass of droplets and ice flecks.
This picture was taken by Ian Pattison, 31, an assistant librarian, outside his home in St Albans last week. He said: 'I got a new phone last week and when I saw this amazing sky, I just grabbed it and started snapping.'
Strange clouds such as these are probably behind one of the most perplexing phenomena of modern times - the UFO sighting.
When agglomerations of condensed water vapour become concentrated-enough, and the light strikes them in the right way, some low-level clouds can give the appearance of being solid objects.
But there was nothing alien over the skies of St Albans last week. Just a lot of very British rain and a sheet of spectacular, if rather unsettling, water droplets in the sky. o you know your cirrus from your cumulo
1. Is it Altocumulus, Altostratus or Cumulonimbus?
2. Is it Cirrostratus, Cirrocumulus or Cirrus?
3. Is it Stratus, Stratocumulus or Nimbostratus?
dailymail.co.uk
