atmosphere
A mixture of gases that surround the Earth. It is "an ocean of air".
gases in our atmosphere
nitrogen - 78%
oxygen - 21%
other gases - 1%
air pressure
It is the measure of the force with which the air molecules push on a surface.
It decreases as you increase in altitude because there is less air above you.
As you increase temperature, this decreases because the molecules become less dense.
5 layers of the atmosphere
troposphere, stratosphere, mesosphere, thermosphere, exosphere
troposphere
The layer where we live. It is where weather occurs. It is the densest layer. It contains 90% of the total mass of the Earth. As you increase in altitude, the temperature decreases.
stratosphere
This is the second layer and contains the ozone layer. As you increase in altitude, the temperature increases.
mesosphere
This is the coldest layer of the atmosphere. As you increase in altitude, the temperature decreases. Meteors burn up in this layer.
ionosphere
This is a "sublayer" that is in thermosphere. Atoms absorb radiation (gamma rays and x-rays) from the sun and turn into ions. This is where the aurora borealis and the aurora australis phenomenons occur.
thermosphere
This layer has the highest temperature of all the layers. As you increase in altitude, the temperature increases. The ISS orbits here.
exosphere
This layer is on the very edge of our atmosphere. This layer borders outer space. Some satellites can orbit the Earth in this layer.
radiation
It is the transfer of energy as electromagnetic waves.
The Earth receives energy from the sun by this.
conduction
It is the transfer of thermal energy (heat) from one material to another by direct contact. When air comes in contact with the Earth's surface, it is heated this way.
convection
It is the transfer of thermal energy (heat) by the circulation or movement of a liquid or gas. This is how air circulates on Earth by warm air rising and cold air sinking.
greenhouse effect
It is the heating process in which the gases in the atmosphere trap thermal energy (heat).
global warming
It is a rise in average global temperatures.
An increase in greenhouse gases, like carbon dioxide (CO2), is believed to have caused an increase in global warming.
Ozone Layer
This is in the upper part of the Stratosphere. This layer absorbs the harmful ultraviolet radiation of the sun.
greenhouse gases
Gases in Earth's atmosphere that trap heat near the surface. Examples are carbon dioxide and methane.
Why is the atmosphere important?
It provides us with the oxygen to breathe, regulates temperature on Earth, it protects the Earth from being hit by meteoroids, protects us from harmful radiation.