Weather

WeatherState or condition of all the variables in

the atmosphere at a given location for any short period of time.

Variables include:1.Temperature

2.Pressure

3.Wind

4.Moisture

Atmosphere

Sphere of Earth where weather takes place.

Broken up into specific sections, each having specific characteristics.

Why is atmosphere important?

oxygen (for respiration/ breathing)carbon dioxide (for photosynthesis)nitrogen (needed for many organic

compounds)Helps control temperatureProtects living things from UV raysNeeded for sound transmissionNeeded for flying critters and aircraft

Composition of the Atmosphere:

All other gasses: CO2, Ar, Methane etc

What makes one layer different from the others?

TemperatureChemical

make upDensity

Kilometer Scale:

goes up by 10’s

Mile Scale:

goes up by 5’s130140

120110

90807060

40302010

1510

5

4045

3035

20

70

8580

656055

11 km7 mi

Weather takes place only in the

troposphere

As altitude increases, temperature in the troposphere______________decreases

Handy Dandy Earth Science Reference Tables: Page 14

15miles

25miles

50miles

80miles

How High?

30km

50km

80km

115km

140km

And in Km’s?

Avg. temp at ground is 15°CGets warmer as you

get higher

Gets colder as you get higher

Gets warmer- atoms moving faster

Temps get colder as you get higher

What are the layers of the atmosphere?

TroposphereStratosphereMesosphereThermosphere

Troposphere

Closest to earth’s surfaceHeight ~10 km (7 miles)90% of atmosphere is hereComponents are well mixedAlmost all weather occurs hereJet stream in upper troposphereTemperature decreases with altitude

(thermal lapse rate = 6.5 ‘C per kilometer)

Stratosphere

Very little moisture/ clouds are rarePilots fly here to avoid weather problemsContains ozone (O3) layer (~25 km)

ozone blocks harmful levels of Ultraviolet radiation from reaching us

Warmer temperatures due to ozone’s reaction with UV light

Mesosphere

Temperature decreases with heightColdest temperature reached in

atmosphere -90 C (~ -130 F)Air is very thin99.9% of atmosphere is below this layerProtects us from meteors (falling stars)

Thermosphere

Warmer layer above mesosphereAir is very thin, but molecules get

lots of energy from the sunTemperature would feel cold to you

because there are so few particles present

Boundaries between layers(constant temperature)

TropopauseBetween troposphere and stratosphere

StratopauseBetween stratosphere and mesosphere

MesopauseBetween mesosphere and thermosphere

What happens to the numberof particles as you increase altitude?

What do you think happens to the weight of the air as a result ?

What do you think happens toair pressure as altitude increases?

What might this look like in a graph?