EARTH’S ATMOSPHERE

EARTH’S ATMOSPHERE

Warner Bros. Movie Trailers: Twister

What gases are in our atmosphere?NitrogenOxygenArgon

Carbon DioxideNeonHeliumMethaneKryptonHydrogen

Bottom Graph is only the tiny sliver from top graph!!!!

Exosphere

Exosphere Highest layer of

atmosphere, 640 km to 10000 km

Boarder between atmosphere and outer space

Hydrogen (H) and Helium (He) are the primary molecules present

Some satellites orbit here.

Thermosphere Height from 85 km to 640 km

– Lower boundary called “Mesopause”

Name means “Heat Sphere”– Temperatures can reach over

1000 o C– Few molecules present absorb

the strong solar energy and heat up

– Even though temperature is very hot, it would feel COLD to us due to the low molecule density!

Temperature increases with height

International Space Station orbits here in Low Earth Orbit (LEO)

Auroras occur here!

IonosphereInside ThermosphereHeight from 80 km to

550 kmHelps radio and

television signals travel– Before satellites, this was

the only way to communicate over very long distances without a wire connecting two places

Full of electrically charged particles (Ions)

Mesosphere Height 50 km to 85 km

– Upper boundary called “Mesopause”

– Lower boundary called “Stratopause”

Coldest layer– Temperature drops with

height– Can be up to minus 100

degrees C Most meteors entering the

atmosphere burn up here

Stratosphere

Height from 18 km to 50 km– Upper boundary called

“Stratopause”– Lower boundary called

“Tropopause” Contains the Ozone Layer Temperature increases

with altitude– Due to absorption of solar

radiation by Ozone Layer

Troposphere

Lowest layer– Surface to 18 km– Upper boundary called

“Tropopause” Temperature decreases

with height 75% of the total mass of

the atmosphere is here! Weather happens here! All non-aquatic life lives

here!

What is the source of all heat and weather

on the Earth?

The SUN is the source of all

heat & weather on Earth.

3 Types of Energy

RADIATIONTransfer of energy through space in the form of electromagnetic waves.

CONDUCTIONTransfer of heat energy through collisions of the molecules of a substance.

CONVECTIONTransfer of heat energy

through motion of liquid or gas caused by differences in density.

Three (3) types of EnergyConduction

Convection

Radiation

• Energy from the sun radiates through space to heat the atmosphere and Earth’s surface by conduction & convection

Energy (Heat) Transfer

Energy transfer among sun, atmosphere & Earth’s surface produces weather

If more energy comes in than leaves, Earth’s temperature will increase

If more energy leaves than comes in, Earth’s temperature will decrease

Heat in the Atmosphere

Heat transfer

Earth’s surfaceabsorbs 51%

Solar energy100%

Atmosphereabsorbs 19%

30% reflected into space(albedo)

Evap

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23%

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Rad

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Con

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Rad

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Energy from the sun heats Earth’s atmosphere and surface. Heat moves through the atmosphere in three different

ways: radiation, conduction, and convection.

Energy transfer between Earth’s surface and the atmosphere creates the WEATHER

Insolation: incoming solar radiation click here for a youtube video

Human Influence on the Atmosphere

Humans can Change the atmosphere

The carbon dioxide content of the atmosphere has increased due to human activities, primarily the burning of fossil fuels:

coal, gasoline, and natural gas.

Human Impact on the Atmosphere

Humans can change the atmosphere

Biologic activity, including human activity, may influence global temperature and climate.

Air pollution – harmful particles caused by volcanoes, forest fires, and human activity.

Acid Rain – sulfur dioxide and nitrogen react with water vapor create an acid rain that kills fish and forests, and damages structures of marble and limestone.

Smog – nitrogen oxides and hydrocarbons (auto exhaust) that, when triggered by solar radiation, create harmful ground-level ozone.

Human Impact on the Atmosphere

Human impact on the atmosphere

Ozone Depletion – a hole in the protective ozone layer created by chlorofluorocarbons (CFCs)

UV

Ray

s

UV

Ray

s

Ozone Creation

CFC kill O3

Human Impact on the Atmosphere

Human impact on the atmosphere

Global Warming – due to increase in greenhouse gases. Rising sea levels Melting polar caps Stronger storms More storms and

droughts Relocation of crop areas

Global Warming = Climate Collapse

INSTRUMENTATION TO

MONITORTHE ATMOSPHERE

Air Temperature

Wind Speed

Humidity

Air Pressure

Wind Direction

Instrumentation

Thermometer measures

temperature

Psychrometer measures humidity

Barometer measures

air pressure

Air PressureA barometer

measures air pressure

Air pressure at sea level is 760mm

barometer

Air PressureChanges because of…

Elevation

Temperature

Humidity

ElevationAs elevation increases, the pressure

decreases since there is less air around you

Denver, CO: 835mb

Sea Level: 1013mb

Temperature

As temperature increases, pressure decreases because the molecules are

further apart

A warm air mass has low

pressure & rises

A cold air mass has high

pressure & sinks

HumidityAs humidity increases, pressure decreases because water molecules are less massive

than air.Humid air rises & has low pressure

Dry air sinks & has high pressure

Air pressure

Isobar: a line that joins points with the same air pressure;

lines closer together mean steeper pressure

gradient

Explain the relationship between air pressure and

1. Temperature2. Elevation3. Humidity

WindsAir flows from high pressure to low

pressure, forming winds

WindsAir over land cools faster & heats faster

than air over watersea breeze: when winds blow inland from

the ocean, because a warm low pressure area is over the land

land breeze: when winds blow off the land to the ocean because a warm low pressure area is over the ocean

Warm low pressure zone over the land

Air rises

Cool high pressure zone over the sea

Air sinks

Wind blows from the sea to the land, filling in the gap left by rising warm air.

Sea Breeze

Cool high pressure zone over the land

Air sinks

Warm low pressure zone over the sea

Air risesWind blows from the land to the sea,

filling in the gap left by rising warm air.

Land Breeze

Draw and Label a Sea Breeze

Include—

1. Air packets2. Areas of High and Low Pressure3. Direction of the wind on the shore

Draw and Label a Land Breeze

Include—

1. Air packets2. Areas of High and Low Pressure3. Direction of the wind on the shore

Wind

Anemometer: instrument to measure wind

speed

Factors Affecting Winds

Coriolis effect Jet stream Global Wind patterns

Coriolis Effect

Coriolis effect: the tendency of an object moving freely over Earth’s surface to curve away from its path of travel, caused by E’s rotation

Northern HemisphereCurve to the right

Southern HemisphereCurve to the left

Coriolis Effect -NorthWinds around a high pressure zone circle clockwise

Winds around a low pressure zone

circle counterclockwise

Youtube animation at 1:29 minutes

What is the direction of a High Pressure system in the Northern Hemisphere?

What is the direction of a Low Pressure system in the Northern Hemisphere?

Jet Streama band of swiftly moving wind, moving east

from west, at the top of the troposphere, unaffected by friction

Global Wind

Patterns

Global Wind Patterns Intertropical convergence zone (ITCZ): low-

pressure zone near equator caused by warm, rising air

trade winds: 5-20° latitudes - warm & steady winds

sub-tropical highs: 20-35° latitudes - air usually sinks - very dry w/ little wind - deserts

polar highs: high pressure regions near the poles (sinking air) - very dry

Horse Latitudes30-35 degrees N/S

Seasonal WindsSummer Land hotter than ocean,

so blows moist air inland Summer monsoon: winds &

rainWinter Ocean hotter than land,

so blows dry air to sea Winter monsoon: winds &

no rain

Temperature maps Colored to show temperatures Often have ISOTHERMS - lines that connect

places with the same temperature

Santa Ana Winds

Monsoons ofBangladesh

(NASA)

Seasonal Monsoon Winds of

Bangladesh

-Cyanobacteria: were blue-green algae thought to be one of the earliest forms of life on Earth appearing about 3.5 billion years ago-These organisms were partially responsible for altering the Earth’s atmosphere increasing the oxygen content

Earth’s Early Atmosphere

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