Atmo = vaporCirru = hairlike curlsStrat = layerCumul = heapedAlto = highIso = equalNimb = light (quick)Baro = weightHygro = moistMeso = middleTrop = turnTherm = heat

Chapter 17 Atmosphere and Weather

Weather = constantly changing; refers to the state of the atmosphere at any given time and place.

Climate = weather patterns based on long periods of time; describes a place or region.

Composition of the Atmosphere

Major Components:

• Nitrogen (78%)• Oxygen (21%)• Argon• Carbon Dioxide• All Others

Composition of the Atmosphere

Variable Components:

• Water Vapor• Ozone• Pollution

Air Pollution http://svs.gsfc.nasa.gov/vis/a010000/a010000/a010012/Ozone Recovery http://www.amnh.org/sciencebulletins/

Temperature and Altitude Pg 480 Fig 6

How far does our atmosphere extend?

MoonEarth

Types of Clouds

Check Yourself!

Height and Structure of the Atmosphere

Pressure:

Weight of air above.

Closer to Earth’s surface = more pressure.

Barometer = measures air pressure

Wind Speed

Measured on the Beaufort Scale Relates wind speed

to its effects Wind chill factor

Anemometers

Sir Francis Beaufort

Relative Humidity Hygrometer

Measures the amount of moisture in the air

Meteorology Meteorologists

study weather How atmosphere

heats and cools How clouds form

and produce rain What makes wind

blow Composition of

atmosphere Cause of past and

present climates

http://www.youtube.com/watch?v=uYctRlQ0gOE&feature=related

Temperature VariationsSeasons

Sun’s rays do not strike surface evenlySolstice vs. Equinox

Earth-Sun Relationships

Earth’s Motions

• Rotation = spinning on its axis• Revolution = movement

around the sunSeasons are a result of the tilt of Earth’s axis remaining the same as the Earth revolves around the sun.

23.5o TiltRotation

Revolution

Vernal Equinox Days begin getting longer.

Summer Solstice First official day of Summer.

Autumnal Equinox Days begin getting shorter.Winter Solstice First official day of Winter.

Vernal EquinoxMarch 21

Autumnal EquinoxSept 22

Summe

r Solstic

eJune 21

Winter SolsticeDec 21

Vernal EquinoxMarch 21

Autumnal EquinoxSept 22

Summe

r Solstic

eJune 21

Winter SolsticeDec 21

Spring and Fall Equinox:All latitudes receive 12 hours of daylight.

DAYLIGHT

Summer Solstice:Northern latitudes receive 24 hours of daylight.Winter Solstice:Northern latitudes receive 24 hours of darkness.

Radiation and Earth’s Atmosphere

100%

INCOMING RADIATION

19%4%

8% 17% 6%

46%

OUTGOING RADIATION

15%

6%

9%

7% 24%

40% 20%

Earth Temperature

Solar radiation is absorbed from the sun during the day.

At night, heat from the day is released from the Earth.

Clear night skies Partly cloudy night skies Cloudy night skies

Solar RadiationReflection = radiation is sent back to space.Scattering = radiation is broken into smaller rays and scattered.Absorption = radiation is absorbed and retained.

Reflection

Absorption

Scattering

Earth Temperature

Solar radiation is absorbed from the sun during the day.

At night, heat from the day is released from the Earth.

Clear night skies Partly cloudy night skies Cloudy night skies

Discovery Ed: The Greenhouse Effect [14:38]

Greenhouse Effect Trapping of the

sun’s energy by the atmosphere

Caused by Greenhouse Gasses CO2, Methane,

CFCs Burning fossil

fuels Coal, oil, & natural

gas Global Warming!

Causes of the Greenhouse Effect

DeforestationCFC’s Burnin

g Fossil Fuels

Industrial Pollution

Eventually we will have a “lid” on our planet!http://environment.nationalgeographic.com/environment/global-warming/quiz-global-warming/

17.3 Temperature Controls

Factors Affecting Atmospheric Temperature:

• Latitude• Heating of Land and Water• Altitude• Geographic Position• Cloud Cover• Ocean Currents

Temperatures also become cooler with altitude.

Normal Lapse Rate 1° every 160m

Temperature InversionGround cools faster than air

Morning fog

Temperature Scales Celsius:

0° - 100° Fahrenheit:

32 °- 212 ° Isolines:

connect points of equal value on maps

Isotherms

Isotherms

Land, Water and Temperature…

Land heats and cools more rapidly than water.

Page 489 Fig 15

Geographic Position and Temperature…

Windward locations are warmer than leeward locations.

Page 490 Fig 16

Altitude and Temperature…

Higher altitudes are colder than lower altitudes.

Page 491 Fig 17

Human Influence and Temperature…

Nat Geo Global Warming Shortshttp://video.nationalgeographic.com/video/player/science/index.html

Cloud Cover, Albedo and Temperature…

Clouds reflect sunlight during the daytime and trap heat from the Earth at night.

Albedo = fraction of total radiation that is reflected.

Disc Ed: Clouds and Patterns of the Weather [21:00]

World TemperaturesIsotherms = lines that connect points that have the same temperature.