The Atmosphere

Objectives:1. Describe the composition of the Earth’s

atmosphere2. Describe the layers of the Earth’s

atmosphere.3. Explain three mechanisms of heat transfer

in the atmosphere.4. Explain the greenhouse effect.

The Atmosphere

One of the four parts that make up the Earth.

Atmosphere – the mixture of gases surrounding the Earth.

The atmosphere insulates the Earth.

The Composition of the Atmosphere

Made mainly of nitrogen, oxygen, carbon dioxide and dust.

The amounts of gases changes due to Animals Plants Vehicles Volcanoes - nitrogen

The Four Layers of the Atmosphere

1. Troposphere – *closest to surface*from 0-18 km (11 miles) up*densest layer*planes fly at about 9 km (6

miles)*weather occurs here*the higher you go, the colder (-

50F) and less oxygenated the air is. Highest place on Earth -

Mt. Everest in the Himalayan Mountains (about 9 km or 5 miles high)

http://www.youtube.com/watch?v=CNTyL6uapjM

The Four Layers of the Atmosphere

2. Stratosphere *from 18- 50 km (11 to 30

miles) up*temperature is warmer than

the troposphere because the ozone layer is located here.

Bottom = -50FTop = -15F *Felix Baumgartner space-dived

from the stratosphere (24 miles up) in October of 2012.

http://www.redbullstratos.com/gallery/videos/all-tags/1

The Four Layers of the Atmosphere

3. Mesosphere *from 50-80 km (30 to 50

miles) up

*temperature is the coldest of all the layers (-90 F)

*meteors entering the atmosphere vaporize in this layer

The Four Layers of the Atmosphere

4. Thermosphere *from 80- 550 km (50 to

350 miles) up

*temperature is the warmest of all the layers (3600 F)

*space shuttles orbit here

Energy in the Atmosphere

Energy from the sun moves through the atmosphere in three ways: Radiation Conduction Convection

Energy in the Atmosphere

Radiation – the transfer of energy across space From the fire to

the pan From the sun to

the earth When you stand

in front of a fire and feel warm

Energy in the Atmosphere

Conduction – flow of heat from a warmer object to a colder object when they are touching Your hand feels

warm when touching the pot handle

Warming your hands with a hot cup of coffee

Energy in the Atmosphere

Convection – the transfer of heat that occurs when hot air rises and cold air sinks. The “rolling” of

boiling water Heat waves rising

from the sidewalk Steam rising from a

hot drink A lava lamp Weather

Energy in the Atmosphere

The Greenhouse Effect Gases such as carbon

dioxide, methane and water vapor in the atmosphere the Sun’s energy and heat the earth.

If this didn’t happen, the earth would be too cold for life.

When we add carbon dioxide to the atmosphere through pollution, the atmosphere traps more heat than normal and temperatures rise!

The Greenhouse Effect

Other examples of the greenhouse effect A greenhouse The inside of a car

on a sunny day