Tuesday 15 November 2011

Amazing Clouds

What can be more peaceful joy than cloud spotting, watching clouds drift across the sky, changing shapes. Clouds are the part of nature's beauty and elegance.
Clouds fill the sky above us and are a part of every day, but they often are unnoticed. However there are some clouds which are so rare that these can attract any human eye!

1. Nacreous Clouds -
These are sometimes called mother-of-pearl clouds. These are 15-25 km high in the stratosphere. Nacreous clouds shine brightly with beautiful colors and have slow movement relative to the lower clouds.




2. Mammatus Clouds -
Mammatus clouds are pouch-like cloud structures and a rare example of clouds in sinking air. Some people have misconception about these clouds. According to them these clouds show that a tornado is about to be formed. But these clouds are harmless, In fact these are usually seen after the worst of a thunderstorm has passed.



3. Altocumulus Castelanus -
These clouds are also called jelly fish clouds because of their jelly fish like appearance. These are formed when the rush of moist air comes from the Gulf Stream and gets trapped between the layers of dry air. The top of the cloud rises into a jelly fish shape and long tentacles, formed from the rain drops which have evaporated.



4. Noctilucent Clouds -
Noctilucent Clouds are also known as Polar Mesopheric clouds. These are extraordinary rare cloud formation that occurs out on the verge of space between 82km to 102km from the earth's surface. These clouds appear to be luminous yet they reflect the sunlight from the other side of the earth at night, giving them a glowing appearance.


5. Mushroom Clouds -
A mushroom cloud is a distinctive mushroom-shaped cloud of smoke, condensed water vapor, or debris resulting from a very large explosion. However any large blast will produce the same kind of effects. For an example, the volcanic eruptions produce the mushroom clouds.


These clouds are produced as a result of the formation of a large mass of hot-low density gases near the ground. The mass of gas rises rapidly and reaches an altitude where it is no longer dense than the surrounding air and disperses, the debris drawn upward from the ground scattering and drifting back down.


6. Cirrus Kelvin-Helmholtz -
These are among one of the most distinctive cloud formations. Appearing as a slender, horizontal spiral of cloud, these tend to dissipate only a minute or two after forming. These clouds are rarely observed. The average height of these clouds is around 16,500 ft.



7. Lenticular Clouds -
Lenticular clouds are stationary lens-shaped clouds that form at high altitudes, normally aligned at right angles to the wind direction. Where stable moist air flows over a mountain or a range of mountains, a series of large-scale standing waves may form on the downwind side.


Lenticular clouds sometimes are formed at the crests of these waves. Under certain conditions, long strings of lenticular clouds can form a wave cloud.


8. Roll Clouds -
A roll cloud is a low, horizontal tube-shaped cloud associated with a thunderstorm gust front, or sometimes a cold front. Roll clouds can also be a sign of possible micro burst activity. These clouds are formed when the cool air lifts the warm moist air then water condenses creating cloud, which often rolls with the different winds above and below.



9. Shelf Clouds -
A shelf cloud is a low, horizontal wedge-shaped cloud, associated with a thunderstorm gust front. Unlike a roll cloud, a shelf cloud is attached to the base of the parent cloud above it. Rising cloud motion often can be seen in the leading part of the shelf cloud.



10. Stratocumulus Clouds -
These low altitude stratocumulus clouds are rolled into long, distinctive ribbons after becoming trapped in air currents. These clouds are very rare to be observed.