The CLAIRE Site Air Quality & Pollution Strategies & Projects Review and Assessments Monitoring Results Industrial Regulations Health & Chemistry Motor Vehicles & Traffic Kids START HERE What is the Environment Meet the Noxious Nine Fun Experiments Lightning Fact or Fiction What is Air Presure? Lichen Land Tips for Children Breeze Town Interesting Facts Teaching Packs Change for Chesham Thames Valley EP Group Tree Planting What is Air Presure? Chilterns Local AIR & Environment
Under pressure Air pressure is the weight of the atmosphere pressing down on the  earth. You may have seen the weatherman talking  about air pressure on TV during a weather  forecast. It is an important thing to know, as it  can actually determine the type of weather we  get where we live.  Air Pressure is measured by a barometer. You can see a barometer on the left. Barometers  may also use mercury in a glass column, like  a thermometer, to measure the change in air  pressure. When the weather is calm the  mercury in the barometer stays fairly low  against the measure. If a high pressure system is on its way, often you can expect cooler  temperatures and clear skies. If a low pressure system is coming, then  look for warmer weather, storms and rain.   Air pressure also changes with altitude. When you move to a higher  place, say a tall mountain in Scotland, air pressure actually decreases  because there are fewer air molecules as you move higher up.
Web Navigation
Kids Zone
Return to Bucks Air Quality Return to Bucks Air Quality