waterspout is a column of cloud-filled wind rotating over a body of water. Despite its name, a waterspout is not filled with water from the ocean or lake. A waterspout descends from a cumulus cloud. It does not "spout" from the water. The water inside a waterspout is formed by condensation in the cloud. There are two major types of waterspouts: tornadic waterspouts and fair-weather waterspouts. Tornadic waterspouts get their start as true tornadoes. Influenced by winds associated with severe thunderstormsair rises and rotates on a vertical axis. Tornadic waterspouts are the most powerful and destructive type of waterspout. Fair-weather waterspouts, however, are much more common. Fair-weather waterspouts are rarely dangerous. The clouds from which they descend are not fast-moving, so fair-weather waterspouts are often static. Fair-weather waterspouts are associated with developing storm systems, but not storms themselves. Both tornadic and fair-weather waterspouts require high levels of humidity and a relatively warm water temperature compared to the overlying air. Waterspouts are most common in tropical and subtropical waters, such as the Florida Keys, the islands of Greece, and off the east coast of Australia.

There are five stages of waterspout formation:

  1. Dark spot. The surface of the water takes on a dark appearance where the vortex, or column of rotating wind, reaches it.
  2.  Spiral pattern. Light and dark bands spiral out from the dark spot. 
  3.  Spray ring. A swirling ring of sea spray called a cascade forms around the dark spot. It appears to have an eye at the center, similar to that seen in a hurricane.
  4.  Mature vortex. The waterspout is now at its most intense stage, visible from the surface of the water to the clouds overhead. It appears to have a hollow funnel and may be surrounded by vapor.
  5. Decay. When the flow of warm air into the vortex weakens, the waterspout collapses. The average spout is around 50 meters (165 feet) in diameter, with wind speeds of 80 kilometers per hour (50 miles per hour), corresponding to the weakest types of tornadoes on land. The largest waterspouts can have diameters of 100 meters (330 feet) and last for up to one hour, though the average lifetime is just 5 to 10 minutes. The National Weather Service recognizes the dangers posed by waterspouts as part of its "severe local storm" warning list. Waterspouts not only put swimmers and boaters at risk, they also pose a threat to aircraft. Helicopters flying near waterspouts can be damaged and thrown off-course by such intense winds.

Credit : National geographic society 

Picture Credit : Google 

How does wind energy work?

A push from the wind can make a kite fly. It can make a sailing boat speed across the water. It can even light lamps and pump water.

People use wind energy to pump water and make electricity for their homes and other buildings. They do it with the help of a machine called a windmill. Windmills come in different shapes and sizes, but they are all alike in some ways.

They are tall enough to catch the strong winds that blow high above the ground. They also have a wheel, which is the part that spins. The wheel has paddles, sails, or blades for the wind to push against. When the wind blows, the wheel spins. This makes a push that runs a water pump or an electricity-making machine called a generator.

Of course, the wind doesn’t always blow, so the windmill doesn’t always run. But water pumped by the windmill can be stored in tanks. And electricity made when the windmill runs can be stored in batteries. Until the windmill goes back to work, people can use stored-up water and stored-up electricity in their homes. There are even “wind farms”, where many windmills make electricity for whole communities.

Picture Credit : Google

Why does Holland have so many windmills?

          The large number of windmills in Holland, or The Netherlands, is due to the fact that they were needed to pump water into the canals off the rich, low-lying land reclaimed from the' sea. Windmills are still used for this purpose today, but pump worked by electricity are more usual. 

          There is an Old Dutch saying, "God made the world, but the Dutch made Holland". They certainly did make a great part of their land by dragging it from the sea, and the battle to hold it never ceases, The name Netherlands (from the Dutch Nederland) means low land, and more than one­ third of Holland's land area of 12,530 square miles lies below sea level.

          Along the coast are dunes of sand-nature's dykes-thrown up by normal tides. The Dutch plant them with marram grass, which holds the sand together with its long, strong, creeping roots. Behind the dunes the Dutch built three dykes of close-packed stone, clay and earth on wooden and concrete piles. The dyke nearest the sea is called a "waker' Behind it lies a "dreamer" and behind that again a "sleeper" Some of the dykes are 200-300 feet high and many have a road or, some, a railway running along the top.

          In 1170 the North Sea swept into the country and formed the bay called the Zuyder Zee (South Sea). In 1421, another high tide flowed in to form the Holland’s Diep (Dutch Deep). The great spring tide of 1953 (two feet higher than any previously re­corded) smashed-the waker dykes, overflowed the dreamers and drowned about 1,900 people. About 50,000 were forced to flee from their homes.

          A famous Dutch story tells of a brave boy who stood for hours with his hand thrust into a hole in a dyke and so prevented the sea from rushing in and widening the breach in the wall.

Picture credit: google

The future of wind power




Wind power will be more important in the future with more wind farms and more powerful turbines. Tall buildings may be designed to catch wind energy and generate electricity. Wind power is also being used to create energy for cars.







These massive wind turbines are in the USA.

Wind turbines are getting bigger and more powerful every year. A typical 1.8 MW (megawatt) turbine will produce enough electricity in a year to meet the power needs of 1,000 homes. New wind turbines now being built are 5 MW or bigger and this means they will make an even bigger contribution to world energy supplies in the future.



Continue reading "The future of wind power"

Arguments against wind power


Some people think that wind turbines spoil the landscape. They also say that wind farms are harmful to wildlife and that they are too noisy if they are built too close to where people live.






Do you think that wind farms spoil the beauty of the countryside?

Wind farms are often built in rural landscapes where there are no other buildings. Because some people think that they spoil the landscape, some think that one solution is to build more offshore wind farms because fewer people would see them.







Wind farms are blamed for killing birds.

Wind farms have been blamed for disturbing wildlife. Some studies suggest that birds, such as eagles, are killed by flying into the giant rotor blades. Other studies suggest that this is not true and that most birds fly over or around them. Before a new wind farm is built, studies are carried out to assess the danger to wildlife.





Some people say wind farms are noisy.

If you stand near a wind turbine you will hear the noise of its rotor blades spinning in the wind. Some people complain that this noise disturbs people living nearby. However, most wind farms are built at least 300 metres from homes. At this distance the noise is less than that of a car engine.