LAYERS OF ATMOSPHEREBY: MR. MERINGOLO

WHAT IS EARTH’S ATMOSPHERE?

• The atmosphere consists of the mixture of gases that surrounds Earth.• The atmosphere has many important functions such as

providing protection from the sun’s damaging rays and maintaining the right temperature range for life on earth

WHAT ARE THE MIXTURE OF GASES FOUND IN THE ATMOSPHERE?• The atmosphere is made up of 78 % nitrogen gas, 21 %

oxygen, and 1 % is other gases.• The atmosphere also contains small particles such as dust,

volcanic ash, sea salt, and smoke. • Water is also found in the atmosphere in which most is found

in the form of water vapor.

HOW DO PRESSURE AND TEMPERATURE CHANGE IN THE ATMOSPHERE?

• Air pressure is the measure of the force with which air molecules push on an area of a surface• Although there are many gas molecules that surround you on Earth, there are

fewer and fewer gas molecules in the air as you move away from the Earth’s surface. So, as altitude increases, air pressure decreases.• As altitude increases, air temperature also changes.• Some parts of the atmosphere are warmer because

they contain a high percentage of gases that absorb solar energy.

WHAT ARE THE LAYERS OF THE ATMOSPHERE?

• Earth’s atmosphere is divided into four layers based on temperature and other properties.• The four layers of the atmosphere are the troposphere,

stratosphere, mesosphere, and the thermosphere.

THERMOSPHERE

• The thermosphere is the uppermost layer of the atmosphere. • Temperatures in the thermosphere can be 1,500 Celsius or

higher. However, the thermosphere feels cold due to the density of particles in the thermosphere being very low.

MESOSPHERE

• The mesosphere is between the thermosphere and the stratosphere. • The temperature decreases as the altitude increases and can

be as low as -120 degrees Celsius at the top of the mesosphere.• Meteoroids begin to burn up in the mesosphere

STRATOSPHERE

• The stratosphere is between the mesosphere and troposphere.• Temperatures generally increase as altitude increases.• Ozone in the stratosphere absorbs ultraviolet radiation from

the sun, which warms the air.

TROPOSPHERE

• The troposphere is the lowest layer of the atmosphere.• This layer contains almost 80 % of the atmosphere’s total

mass, making it the densest layer.

HOW DOES THE ATMOSPHERE PROTECT LIFE ON EARTH

• The atmosphere surrounds and protects Earth.• The atmosphere provides us with the air we breathe• Protects Earth from harmful solar radiation and from space

debris that enters the Earth system.

THE GREENHOUSE EFFECT

• The greenhouse effect is the process by which gases in the atmosphere absorb and give off infrared radiation. • Greenhouse gases in the atmosphere absorb some of this

infrared radiation and then reradiate it.• Because greenhouse gases keep energy in the Earth system

longer, Earth’s average temperature is kept at around 15 degrees Celcius.

THE GREENHOUSE EFFECT