The spectacular clouds

The spectacular clouds that look as if they were sculpted out of the sky. They drift through the atmosphere, looking as if they have been elaborately sculpted by an artist from above.

The fleecy white clouds that usually litter the sky like cotton wool have been carved into waves and volcanoes and shapes of extraordinary beauty.

Cumulus Clouds blanket the skies

From swirling Lenticular clouds to pouch shaped Mammatus clouds these are some of the rarest formations known to meteorologists.

Clouds are visible mass of droplets, suspended in the atmosphere above the surface of the Earth or another planetary body.

Roll clouds loom over Sydney, Australia

A Shiveluch Volcano cloud erupts in the atmosphere

Generally they 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.

Classified into four categories (High Level, Mid-Level, Low-level and Vertically developed), meteorologists use clouds to predict climate and weather patterns and even studying the impact of global warming.

A Sarchev Volcano eruption cloud bursts out of the sky with brown fumes

A Kelvin Helmholz Wave cloud drifts across the sky at sunset

The Mammatus clouds, the strange globular clouds pictured below, 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, it is a rare but perfectly natural (and perfectly harmless, provided you do not try to fly through it in light aircraft) meteorological phenomenon.

Mammatus clouds are a sign of the massive quantities of water vapour that are held in the languid summer air

Strange clouds such as these are probably behind one of the most perplexing phenomena of modern times - the UFO sighting.

Earlier this year, the Cloud Appreciation Club, launched 'The Cloud Collector's Handbook' to enable cloud-spotters to identify rare and unusual formations. ( dailymail.co.uk )