Air Pressure can vary at any particular point on the Earth depending on the density of the air Density = mass / volume
Where is air pressure higher, up in the mountains ordown in thevalley?
http://www.youtube.com/watch?v=GWEyFbyv Elc&feature=related Air Pressure and Altitude
This bottle was photographed at 3600m (left) then again at sea level (right) At sea level, because air is compressible, the weight of all that air above us compresses the air around us, making it denser.We all live underneath a huge ocean ofair that is several miles deep: theatmosphere.The pressure on our bodies is about thesame as ten meters of sea waterpressing down on us all the time.
Density = Mass / Volume Warm air is less dense than coolair. Warm air rises. Cool air sinks. Air at high altitudes is less dense than air at lower altitudes.
Factors that affect Air PressureTemperature Water Vapor Elevation
TEMPERATURE AND AIR PRESSURE Molecules HEAT move fasterLESS AIR MovePRESSURE apart, become fewer and weigh less
HIGHTEMPERATURE, LOW AIRPRESSURELOWTEMPERATURE, HIGH AIRPRESSURE
AMOUNT OF WATER VAPOR consists of air and water molecules
More water vapor meansless air molecules (more water molecules) LOW AIR PRESSURE DRY AIR = HIGH AIR PRESSURE
High pressure generallymeans fair weather Air mass in upper atmosphere No clouds Warm, moi st airLayer of Air cannot rise
Low pressure generally means cloudy, rainy weather Warm airAir masses rises, cloudsmove apart form
High Pressure System: Indicates clear, calmWeather map conditions with reduced chance of precipitation. Drier air usually results in a greater range of high and low temperatures.Low pressure system: Increasedcloudiness, winds, temperatures, and chanceof precipitation.
Measuring Air Pressure Types of BarometerAir Mercury BarometerPressure Aneroidis measuredby aninstrument
Air pressureincreases, column of mercuryrises Air pressure decreases, colu mn of mercury drops
High Pressure:Rising or steady - Continued fairSlowing falling - FairRapidly falling - Cloudy, WarmerMedium pressure:Rising or steady - Same as presentSlowing falling - Little changeRapidly falling - Precipitation likelyLow Pressure:Rising or steady - Clearing, coolerSlowing falling - PrecipitationRapid falling - Storm
Factors Affecting Air Pressure FACTOR Increase/Decrease Air PressureDensityDensityTemperatureTemperatureWater VaporWater VaporAltitudeAltitude
At the top of a mountain How does air pressure you drank a bottle of affect scuba diving?water, sealed it, but imploded on yourway down. Why? A rising barometer A series of hot, humid indicates a spell of days is preceded by a cool dry weather. falling barometer.A southern, coastal areas tend to have Rapidly droppinglower air pressure than an inland area temperatures arefarther north. accompanied by a rising barometer.You are planning a Why would a seriousPicnic and check the athlete decide to trainbarometer, which is at a high altitude?falling. Why should youcancel the picnic?You are hiking Mount Everest How does a hot airand find it hard to breathe at balloon work?a high altitude.