Wind Direction and Strength Notes PDF

5.2 Geography Department WIND DIRECTION AND STRENGTH (NOTES) We describe the wind by talking about its strength or speed, and the direction in which it is blowing. We can see the direction the wind is blowing by looking at a w...

5.2 Geography Department WIND DIRECTION AND STRENGTH (NOTES) We describe the wind by talking about its strength or speed, and the direction in which it is blowing. We can see the direction the wind is blowing by looking at a weather vane on a tall building or a flag on a flagpole. We name a wind by the compass direction from which it blows. Example: North wind >>> wind that blows from the north towards the south wind sock weather vane  The winds that always blow in the same direction are called prevailing winds. There are belts of high air pressure and low air pressure. The air pressure is low around the equator. Three main belts of prevailing winds are The trade winds The Westerlies The Polar Easterlies The trade winds get their name from the sailing ships. The Beaufort scale Wind speed >>> a measure of the strength of the wind. (how fast the air is moving.) The Beaufort scale is worked out by Admiral Sir Francis Beaufort in 1805 to measure wind speed at sea. The Beaufort scale goes from 0 (dead calm with no wind) to 12 and over (hurricane). How to measure wind speed The scientific instrument for measuring wind speed is called an anemometer. It has four little cups that turn in the wind. The cups are attached by a shaft to a meter. anemometer