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Friday 21 June 2019

Wind

On the surface of the Earth, the wind is the lateral movement of its atmosphere.

By W.carter - Own work, 

Although modified by features such as land and water, there is a basic worldwide wind system. A belt of low pressure (the doldrums) lies along the Equator. The trade winds blow towards this from the horse latitudes (high pressure areas about 30 degrees north and 30 degrees south of the Equator), blowing from the north east in the northern hemisphere, and from the south east in the southern hemisphere.

Short bursts of fast winds are called gusts. Strong winds that go on for about one minute are called squalls. Winds that go on for a long time are called many different things, such as breeze, gale, hurricane, and typhoon.

A gale force wind is a wind blowing between 39 to 54 miles per hour. A wind blowing from 4 to 31mph is a breeze.



FAMOUS WINDS

The trade winds are the prevailing pattern of easterly surface winds found in the tropics, within the lower portion of the Earth's atmosphere. They occur in the lower section of the troposphere near the Earth's equator. The trade winds blow predominantly from the northeast in the Northern Hemisphere. They blow from the southeast in the Southern Hemisphere. They are stronger during the winter and when the Arctic oscillation is in its warm phase.

The monsoon is a seasonal wind of South Asia, blowing from the southwest between April and October to bring the rain on which crops depends, and from the northeast in winter.

Ratangrad, India monsoon

A föhn is a type of dry, warm, down-slope wind that occurs in the lee (downwind side) of a mountain range. Central Europe enjoys a warmer climate due to the Föhn, as moist winds off the Mediterranean Sea blow over the Alps.

Chinook winds are dry warm föhn winds in the interior West of North America, where the Canadian Prairies and Great Plains meet various mountain ranges. After blowing in from the Pacific and being forced to rise over the mountains, the moisture in the air is condensed and falls out as precipitation. After losing its moisture, the dried air then descends on the leeward side of the mountains, warming at the dry adiabatic rate of 10 °C / 1000 m (5.5 °F / 1000 ft).


The Santa Anna is a periodic warm wind from the inland deserts that strikes the California coast.

The dry northerly mistral, which strikes the Mediterranean area of France, is an unpleasantly cold wind.

The doldrums is a wind-free area around the Equator where sailing ships used to get stuck for weeks. Hence the phrase 'in the doldrums'.

In outer space, solar wind is the movement of gases or particles from the sun through space.

HISTORY

Today you only really need to remember four names (North, East, South, West) to get around, but ancient Greeks and Romans had to memorize twelve different wind names to orient themselves.

On November 26, 1703, high winds and torrential rain swept across eastern England. The 80 mph hurricane decimated villages, killing between 8,000 and 15,000 people. Ships were blown hundreds of miles off-course, and over 1,000 seamen died on the Goodwin Sands alone. Homes were destroyed and animals drowned in flood water, News bulletins of casualties and damage were sold all over England – a novelty at that time.

When Sir Francis Beaufort designed his scale of wind strength in 1805, it was based on the effect of wind on the sails of a frigate. His 13 categories of wind strength ranged from "just sufficient to give steerage" to "that which no canvas sails could withstand".

The wind scale is now: 0 (calm) to 12 (hurricane), with five more levels for tropical cyclones.

The first house in the world to have its electricity supplied by wind power was in Kincardineshire, Scotland in 1887.

Wind farm

RECORDS

The strongest surface wind gust ever recorded not in a tornado was 408 km/h; 253 mph on April 10 1996 on Barrow Island, Australia during the passage of Tropical Cyclone Olivia. The winds were over three times as fast as those in most hurricanes.

The strongest ever surface wind gust in the Northern Hemisphere not in a tornado was measured at 231 mph on the summit of Mount Washington, New Hampshire, United States, on April 12, 1934.

A Doppler on Wheels team measured the fastest winds recorded on Earth (301 ±20 mph, or 484 ±32 km/h) in a tornado near Bridge Creek, Oklahoma on May 3, 1999.


The highest verified gust of wind in the United Kingdom was 173mph, on March 20, 1986, in the Cairngorms.

The strongest winds found on any planet in our solar system are found on Neptune. Wind speeds there reach up to 1,500 miles per hour (2,400 kilometers per hour).

FUN WIND FACTS 

A device to measure wind speed is called an anemometer (from 'anemos' the Greek for wind). In Greek mythology, the anemoi were four wind gods, causing wind from the four compass points.

Chill temperature is an index that indicates how cold the air feels to the human body, taking into account both the air temperature and wind speed. The current formula for Wind Chill, implemented in 2001, is based on the assumption of a person walking into a wind at a speed of 5.0 km/h (3.1 mph) with a bare face, facing the wind in an open field. This formula corrects the officially measured wind speed to the wind speed at face height. 

Wind is not normally colder than the air around you. Your body heats a thin film of air around you that keeps you warm. Wind moves it and cools you down.


Weathervanes point to where the wind is coming FROM, not the direction it’s blowing.

Over four per cent of the world's energy production now comes from wind power.

Wind is essential for trees to reach maturity. The stress from wind allows trees to grow stronger, and without wind, a tree will eventually collapse under its own weight.

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