Nature Photos

July 30, 2008

 

Eclectic Collection!

 

Lenticular clouds, technically known as altocumulus standing lenticularis, 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 form at the crests of these waves. Under certain conditions, long strings of lenticular clouds can form, creating a formation known as a wave cloud.

 

How lightning initially forms is still a matter of debate. Scientists have studied root causes ranging from atmospheric perturbations (wind, humidity, friction, and atmospheric pressure) to the impact of solar wind and accumulation of charged solar particles. Ice inside a cloud is thought to be a key element in lightning development, and may cause a forcible separation of positive and negative charges within the cloud, thus assisting in the formation of lightning.

 

This is what the Earth looks like at night. Human-made light reveals particularly developed or populated areas of the Earth's surface, including the seaboards of Europe, the eastern United States, and Japan. Many large cities are located near rivers or oceans so that they can exchange goods cheaply by boat. Particularly dark areas include the central parts of South America, Africa, Asia, and Australia. The above image is a composite of hundreds of pictures made by orbiting satellites.

 

Sharks are beautiful, impressive creatures, but they're better enjoyed from a distance - especially when we're visiting their home and might be mistaken for lunch! Knowing what situations to avoid can help to lower your chance of becoming a shark's accidental snack.

 

A wall cloud, or pedestal cloud, is a cloud formation associated with thunderstorms. It is a marked lowering typically beneath the rain-free base portion of a deep cumulus cloud, and indicates the area of primary and strongest updraft which condenses into a cloud at altitudes lower than that of the ambient cloud base. Most strong tornadoes form within wall clouds.