CHARACTERISTICS OF THE ATMOSPHERE

Composition of Atmosphere Made up mostly

of Nitrogen (N) Oxygen makes up

a little more than 20%

Atmospheric Pressure

Gravity pulls molecules towards Earth

Creates air pressure

Atmosphere is held by gravity

As altitude increases, air pressure decreases

Atmospheric

Temperature As altitude

increases, temperature decreases

Lower part of atmosphere is warmer

Contains high percentage of gases that absorb solar energy

Layers of the Atmosphere Troposphere

Stratosphere

Mesosphere

The layer in which we live

Lies next to Earth’s surface

Home of the Ozone layer

Middle layer Coldest layer

Layers of the Atmosphere cont’d Thermosphere

Ionosphere

Edge of the Atmosphere

Uppermost layer

Home of the Auroras Upper Mesosphere

and Lower Thermosphere

Nitrogen and Oxygen absorb harmful solar energy

GLOBAL WINDS AND LOCAL WINDS

Why Air Moves Equator and Poles Cold air sinks

Creates a high pressure around the poles

Cold air then flows toward the equator

Pressure Belts

Coriolis Effect

Every 30° latitude Bands of high and

low pressure

Curving of path of currents due to Earth’s rotation

Global Winds Polar Easterlies

Westerlies

Wind belts that extend from the poles to 60° latitude

Wind belts found between 30° and 60° latitude

Trade Winds

Doldrums

Winds that blow from 30° to almost the equator

Where trade winds meet around the equator

Horse Latitudes

Jet Streams

At about 30° North and 30° South

Sinking air creates an area of high pressure

Narrow belts of high-speed winds

Blow in the upper Troposphere and lower Stratosphere

Local Winds

Mountain and Valley Breezes

Sea and Land Breezes

Generally move short distances

Can blow from any direction

Caused by an area’s geography

Affected by temperature

Sea Breeze

Land Breeze

wind that blows from an ocean or lake to land

land warms faster than water

happens during day

winds that blow from land to a body of water

land cools faster than water

happens at night

AIR POLLUTION

Primary Pollutants

Secondary Pollutants

Pollutants put directly into the air by human or natural activity

When primary pollutants react with other primary pollutants or natural substances (water vapor)

Industrial Air Pollution

Indoor Air Pollution

Burning of fossil fuels

Ex: Power plants

Sometimes can be more polluted than outside air

Ozone Ozone Hole Layer is thinning

over the Arctic and Antarctic regions

Allows more UV radiation to reach Earth’s surface

CFCs cause Ozone depletion

CFCs remain active for 60-120 years

Human Effects from Air Pollution Short-term effects

Long-term effects

Coughing Sneezing Headaches Eye irritation

Lung cancer

Clean Air Act

EPA

Requires many industries to use pollution-control devices

Sets air quality standards-