What is Wind

What is Wind

 What is wind? The wind has always been very important to humans. We use it for sailboats and we make electricity from wind turbines. Wind can be used to fly kites to pump water and many other things. Wind can dry your clothes in the summer or chill you to your bones in the winter. 

What is wind?

Wind is produced by the uneven heating of the earth’s surface by the sun. It takes only eight minutes for sunlight to travel from the Sun to the surface of the Earth. As the Earth’s surface warms, so does the air that touches it. And when the air gets warm enough, it rises high into the sky. This is how hot air balloons fly. When warm air rises, nearby air that’s cooler rushes in to fill the empty space left behind. The rushing air is what we call wind. Since the earth’s surface is made of different land and water formations, it absorbs the sun’s heat unevenly. Air under high pressure moves toward areas of low pressure. The greater the difference in pressure, the faster the air flows. Wind is made up of 78% Nitrogen, 21% oxygen and 1-4% water vapour.

Wellington Winds

Wellington sees gusts of about 75km 50 days of the year at the airport while Auckland's winds get over 65km/h on only about 50 days of the year, while Christchurch averages 60 days and Invercargill 90. Wellington's strongest recorded gust of 247kmh was measured on Hawkins Hill in 1962, just a few miles from the city centre. On average Wellington can see 173 days above 59km/hr and 22 days above 74km/hr. 233 was the number of days winds topped gale-force speed in Wellington's windiest year.

Wind energy 

Windmills have been in use since 2000. They were first developed in Persia and China. Ancient mariners used wind power to sail to different lands, and farmers used it to pump water and for grinding grains.

The largest wind turbine in the world is in Hawaii, USA. It stands 20 stories tall and has blades the length of a football field. The first house in the world to have its electricity supplied by wind power was in Kincardineshire, Scotland in 1887. The largest turbines can harness energy to power 600 UK homes. These turbines form wind farms and hundreds are arranged in lines in windy spots like a ridge.