1 / 14

Air Pressure

Air Pressure. Air Pressure. Air pressure: measure of the force with which air molecules push on a surface. Air Pressure is GREATEST at the surface of Earth because there is the most atmosphere above. Air Pressure is dependent on DENSITY.

nellyd
Download Presentation

Air Pressure

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Air Pressure

  2. Air Pressure • Air pressure: measure of the force with which air molecules push on a surface. • Air Pressure is GREATEST at the surface of Earth because there is the most atmosphere above

  3. Air Pressure is dependent on DENSITY • Denser air will have a higher air pressure- more air molecules in a given space • Less dense air will have a lower air pressure- fewer air molecules to push down. Less Dense= fewer particles to push down on you More Dense= more particles to push down on you

  4. Air Pressure is affected by: • 1- Elevation (or altitude) • 2- Temperature • 3- Water content

  5. Impact of Elevation on Air Pressure • As you move up through the atmosphere, air pressure decreases. • There are fewer air molecules above, so the force of the air will be less.

  6. Impact of Water Content, or humidity, on Air Pressure • Moist air is less dense than dry air, and therefore has a lower air pressure. • A water molecule has less mass than other molecules that make up the air. N H2O N O Weighs less since H2O is lighter than Nitrogen and Oxygen O H2O O N

  7. Impact of Temperature on Air Pressure • Warm air is less dense than cold air. Therefore, warm air has a lower pressure • The molecules in warm air are moving fast and are spread farther apart. Warm Air Cold Air

  8. Barometer • The piece of equipment used to measure air pressure is a Barometer Mercury Barometer Aneroid Barometer

  9. Mercury Barometer

  10. Air Pressure Affects the Weather • Low air pressure usually results in Bad weather: stormy, cloudy, overcast. • High air pressure usually results in Good weather: clear skies, no precipitation • Air pressure in a weather system reflects the amount of water in the air, which affects the weather.

  11. Low pressure • usually bring cloudy and wet days. • In the Northern Hemisphere, a low-pressure system forces winds to spiral counterclockwise. • Air is forced toward the center and up. • As the air rises, it cools • Cold air can’t hold as much water vapor as warm air, so the water condenses or comes together, to form clouds. • When the water droplets join together and get too heavy, they may fall as rain/snow

  12. High pressure • Usually bring clear and calm conditions • In the Northern Hemisphere, high-pressure system winds spiral clockwise, moving from the center outward. • To replace the air that flows out of the storm’s center, more air is sucked down from up higher in the atmosphere. • This air warms up as it is pulled down. The warm air expands, and any clouds or precipitation that had formed disappear.

  13. Air Pressure on a Weather Map • Areas of High and Low pressure on shown on a weather map with an H or an L.

More Related