Weather - Chapter 1Weather - Chapter 1
The AtmosphereThe Atmosphere
![MC900301082[1]](data/images/img0.png)
What is weather?
Refers to the state of theatmosphere at a specific time andplace. Refers to the state of theatmosphere at a specific time andplace.
The one thing that you can talkto anybody about! The one thing that you can talkto anybody about!
If you don’t like the weather justwait around it will change! If you don’t like the weather justwait around it will change!
1.1 The Air Around You1.1 The Air Around You
Weather is constantlychanging
The atmosphere is theenvelope of gases thatsurrounds the planet
Composition of theatmosphereComposition of theatmosphere
NITROGEN (N2): 78%NITROGEN (N2): 78%
OXYGEN (O2): 21%OXYGEN (O2): 21%
Other: 1%Other: 1%
CARBON DIOXIDECARBON DIOXIDE
WATER VAPORWATER VAPOR
METHANEMETHANE
ARGONARGON
PARTICLES (dust, smoke, salt,chemicals)PARTICLES (dust, smoke, salt,chemicals)
Atmosphere CharacteristicsAtmosphere Characteristics
• Water vapor is the source of allclouds and precipitation. Likecarbon dioxide, water vaporabsorbs heat given off by Earth.It also absorbs some solarenergy.
Ozone is a form of oxygen thatcombines three oxygen atomsinto each molecule (O3).Ozone is a form of oxygen thatcombines three oxygen atomsinto each molecule (O3).
If ozone did not filter most UVradiation and all of the sun’s UVrays reached the surface ofEarth, our planet would beuninhabitable for many livingorganisms.If ozone did not filter most UVradiation and all of the sun’s UVrays reached the surface ofEarth, our planet would beuninhabitable for many livingorganisms.
It forms when lighteninginteracts with oxygen in the air.It forms when lighteninginteracts with oxygen in the air.
1.2 Air Pressure1.2 Air Pressure
Properties of AirProperties of Air
Because air has MASS, it also hasother properties, including DENSITYand PRESSURE.Because air has MASS, it also hasother properties, including DENSITYand PRESSURE.
DensityDensity
D = M/VD = M/V
Pressure- the force pushing on anarea or surface.Pressure- the force pushing on anarea or surface.
Air Pressure- The result of theWEIGHT OF A COLUMN OF AIRPUSHING DOWN on an area.Air Pressure- The result of theWEIGHT OF A COLUMN OF AIRPUSHING DOWN on an area.
Air pressure changes from day today. Denser air exerts morepressure than less dense air.Air pressure changes from day today. Denser air exerts morepressure than less dense air.
–Measuring Air Pressure
•Barometer
–an instrument that is used to MEASUREAIR PRESSURE.
–Two common kinds:
1. MERCURY Barometers-glass tubeopen at the bottom end and partiallyfilled with mercury
»Mercury is pushed higher with moreair pressure.
2. ANEROID Barometers-air tightmetal chamber that is sensitive tochanges in pressure.2. ANEROID Barometers-air tightmetal chamber that is sensitive tochanges in pressure.
METAL SPRING AND DIALMETAL SPRING AND DIAL
Fig 6, page 13Fig 6, page 13
Measuring air pressure - unitsMeasuring air pressure - units
Several different units usedSeveral different units used
Most use – inches of mercury (Hg)Most use – inches of mercury (Hg)
Based on the height of the column of Hg in aHg barometer. “30 inches of mercury”Based on the height of the column of Hg in aHg barometer. “30 inches of mercury”
National Weather Service indicates pressureas millibarsNational Weather Service indicates pressureas millibars
1 inch of Hg = 33.87 millibars1 inch of Hg = 33.87 millibars
eg. 30 in Hg = 33.87 millibars eg. 30 in Hg = 33.87 millibars = 1,016 millibars
1 in of Hg 1 in of Hg
Hectopascal (symbol hPa) is a SI unit, Hectopascal (symbol hPa) is a SI unit, one millibar isequivalent to 100 pascals or one hectopascal. 1mb = 1hPa
Altitude and Air PressureAltitude and Air Pressure
Altitude and properties of AirAltitude and properties of Air
Altitude: ELEVATION OR DISTANCEABOVE SEA LEVELAltitude: ELEVATION OR DISTANCEABOVE SEA LEVEL
Altitude and Air Pressure/Density:Altitude and Air Pressure/Density:
INVERSELY PROPORTIONALINVERSELY PROPORTIONAL
Increase in ALTITUDE =Decrease in air PRESSURE,LESS air pushing down fromabove you.Increase in ALTITUDE =Decrease in air PRESSURE,LESS air pushing down fromabove you.
Altitude and DensityAltitude and Density
The density of air decreases as altitude increases.Air at sea level has more gas molecules in each cubicmeter than air at the top of a mountain.The density of air decreases as altitude increases.Air at sea level has more gas molecules in each cubicmeter than air at the top of a mountain.
Air Pressure
measured in
units of
measured
with
decreases
as
Densitydecreases
Altitude
increases
Millibars
Inches ofmercury
Barometers
Aneroid
include
Mercury
GraphicOrganizer
1.3 Layers of the Atmosphere1.3 Layers of the Atmosphere
Layers of the atmosphereLayers of the atmosphere
There are 4 layers in theatmosphere classifiedaccording totemperature changes.There are 4 layers in theatmosphere classifiedaccording totemperature changes.
They are thetroposphere,stratosphere,mesosphere, and thethermosphere.They are thetroposphere,stratosphere,mesosphere, and thethermosphere.
Troposphere
•This is the layerthat is closest tothe surface ofthe earth
•It’s elevationranges from 0 to12 km
•Weather onlyoccurs here
StratosphereStratosphere
This layer sits on topof the troposphereThis layer sits on topof the troposphere
It’s elevation rangesfrom 12 km to around50 kmIt’s elevation rangesfrom 12 km to around50 km
This layer containsthe ozone layer, whichprotects the earthfrom ultravioletradiation from thesun.This layer containsthe ozone layer, whichprotects the earthfrom ultravioletradiation from thesun.
MesosphereMesosphere
This layer is abovethe stratosphereThis layer is abovethe stratosphere
It’s elevation rangesfrom 50 to 80 kmIt’s elevation rangesfrom 50 to 80 km
This layer protects theearth from getting hitfrom asteroidsThis layer protects theearth from getting hitfrom asteroids
ThermosphereThermosphere
This is the highest layerof the atmosphereThis is the highest layerof the atmosphere
It’s height ranges from 80to 400 kmIt’s height ranges from 80to 400 km
This is where most smallmeteorites burn up and isalso the location in theatmosphere that thenorthern lights occur(aurora borealis)This is where most smallmeteorites burn up and isalso the location in theatmosphere that thenorthern lights occur(aurora borealis)
It is divided into theionosphere (lower layer)and exosphere (upperlayer)It is divided into theionosphere (lower layer)and exosphere (upperlayer)
Changing TemperaturesChanging Temperatures
The graph showshow temperaturesin the atmospherechange withaltitude.The graph showshow temperaturesin the atmospherechange withaltitude.
Use it to answer thequestions thatfollow.Use it to answer thequestions thatfollow.
Changing TemperaturesChanging Temperatures
What twovariables arebeinggraphed? Inwhat unit iseachmeasured?
Changing TemperaturesChanging Temperatures
Temperature andTemperature and
altitude degreesCelsius andkilometersaltitude degreesCelsius andkilometers
Graph AnalysisGraph Analysis
What is thetemperature at thebottom of thestratosphere?
Which layer of theatmosphere has thelowest temperature?
Describe howtemperature changesas altitude increases inthe troposphere.
1.4 Air Quality1.4 Air Quality
Pollutants- harmful substances in the air,water and soilPollutants- harmful substances in the air,water and soil
They can affect human health and otherthingsThey can affect human health and otherthings
Sources of PollutionSources of Pollution
Natural sources- forest fires, soil erosion and duststorms. Wind carries particles of mold andpollen. Volcanoes emit clouds of gas, dust, andash.Natural sources- forest fires, soil erosion and duststorms. Wind carries particles of mold andpollen. Volcanoes emit clouds of gas, dust, andash.
Human activities- farming, construction, burning offossil fuels (coal, oil, gas, diesel fuel)Human activities- farming, construction, burning offossil fuels (coal, oil, gas, diesel fuel)
Fossil fuels produce a variety of pollutantsincluding carbon monoxide, nitrogen oxides andsulfur oxidesFossil fuels produce a variety of pollutantsincluding carbon monoxide, nitrogen oxides andsulfur oxides
Smog and Acid RainSmog and Acid Rain
Burning of fossil fuels can cause smog and acid rainBurning of fossil fuels can cause smog and acid rain
London-Type Smog- created when particles in coal smoke combinewith water droplets in humid airLondon-Type Smog- created when particles in coal smoke combinewith water droplets in humid air
Photochemical Smog- brown haze formed by the action of sunlighton pollutants such as hydrocarbons and nitrogen oxides. This is acombination of ozone and other pollutants.Photochemical Smog- brown haze formed by the action of sunlighton pollutants such as hydrocarbons and nitrogen oxides. This is acombination of ozone and other pollutants.
Acid Rain- forms when nitrogen oxides and sulfur oxidescombine with water to form nitric acid and sulfuric acid.Acid Rain- forms when nitrogen oxides and sulfur oxidescombine with water to form nitric acid and sulfuric acid.
Rain, sleet, snow, fog and dry particles can carry theseacids to trees and lakes.Rain, sleet, snow, fog and dry particles can carry theseacids to trees and lakes.
It can damage buildings and statues and can makewater inhabitable for plants and organism.It can damage buildings and statues and can makewater inhabitable for plants and organism.
Before and AfterBefore and After
Effects of PollutionEffects of Pollution
Air pollution cancause many differentproblems. This tableshows the healtheffects of airpollution. Pollen alsocan cause difficultiesfor people withallergies.Air pollution cancause many differentproblems. This tableshows the healtheffects of airpollution. Pollen alsocan cause difficultiesfor people withallergies.
Improving Air QualityImproving Air Quality
The Environmental Protection Agency (EPA)monitors air pollutants in the United States.The Environmental Protection Agency (EPA)monitors air pollutants in the United States.
New model cars and power plants produce fewerpollutants than older models.New model cars and power plants produce fewerpollutants than older models.
Cities are still polluted because there are morepower plants and cars with the increase inpopulation.Cities are still polluted because there are morepower plants and cars with the increase inpopulation.
Reducing pollution can be very expensive.Reducing pollution can be very expensive.