weather [wind] [2] [comprehension quiz]

Wind is the movement of air masses around the Earth. The movement is caused by the difference in the air pressures of these air masses. This is shown here over a map of Australia. These air masses are either: areas of low pressure [L] or areas of high pressure [H]. Here is a satellite picture showing a high pressure area and a low pressure area over the UK. High pressure areas [H] always move towards low pressure areas [L]. High pressure areas [H] are areas of cool, dry and usually good weather. Whereas, low pressure areas [L] are areas of warm, moist and usually bad weather. By now you must be wondering how do you measure air pressure. This object is called a barometer and it measures air pressure in units called millibars.

1. What is wind? the movement between atmospheric layers the movement of air masses the movement of warm air upwards 2. In which direction do winds move? high pressure to low pressure low pressure to high pressure low and high pressure to equator 3. Which instrument is used to measure air pressure? anemometer thermometer barometer 4. Which unit is air pressure measured in? millipedes millibars milliseconds 5. What causes wind? heat from the Sun the rotation of the Earth the difference in air pressure

There are 6 pictures in a grid. As you hover over each picture a blue screen appears on which there is some information about what is being shown in the picture. Read this information and look at each picture to make sure you understand what is being shown. If you want to check how much you understand try the quiz on the right hand side. To start the activity again just refresh the page.