Layers of the Atmosphere
Earth's atmosphere is broken down into several layers. These layers are made up of gases that have a similar density, temperature, and other properties.
The layers of our atmosphere all help keep earth habitable and safe. Notice that the diagram shows 5 layers. Each of these layers has specific properties. There is also a region that stretches from the upper mesosphere to the exosphere, referred to as the ionosphere. This region is special, but is not really a layer. |
Layers of Earth's Atmosphere
Troposphere 0 - 12 km Because the Troposphere is the one that touches the ground, it is also the densest layer (contains 90% of gases). The weight of all of the layers above compress it and keep the molecules closer together than they are in the other layers! We live in the troposphere and it is where weather occurs! This is also the layer where most water vapor is found, which creates weather via the water cycle |
Stratosphere
12 - 50 km Contains the OZONE LAYER The Ozone Layer a band of O3 molecules found within the Stratosphere. These O3 molecules absorb much of the sun's UV radiation, protecting the earth. The ozone layer keeps the Stratosphere warm. The Jet Stream, strong upper level winds that affect weather and plane transportation, are found in the lower part of the stratosphere, where it meets the troposphere |
Mesosphere
50 - 80 km Coldest layer Protects Earth from meteors (rocks moving through space). When they move through earth's atmosphere the meteors (then called meteoroids) "burn up" due to friction with the gases in the mesosphere. The gas molecules in the layers above the mesosphere are too far apart to create enough friction to damage the meteoroids. |
Thermosphere
80 km to 400 km Hottest Layer because molecules absorb the most energy from the sun, so they move the most (but are few and far between!) The thermosphere would FEEL cold (because the fast moving molecules would rarely touch you) but since temperature is a measure of how fast molecules are moving (their kinetic energy) it is technically the hottest! Exosphere 400 + Earth's atmosphere disappears into the vacuum of space Satellites are usually found in the upper regions of the Thermosphere or in the Exosphere |
Ionosphere --- a ZONE, not a layer
The ionosphere is a zone of Earth's atmosphere where the atoms found in the layer are turned into ions (charged atoms) and free floating electrons (pieces of atoms that have a negative charge) by the sun's rays. |
|
- Stretches from the mesosphere to the exosphere, but it varies depending upon the sun's behavior
- Where the Aurora Borealis (Northern Lights) occurs
- Reflects radio waves back towards Earth, so our radio signals can travel a long distance
- Where the Aurora Borealis (Northern Lights) occurs
- Reflects radio waves back towards Earth, so our radio signals can travel a long distance
Temperature Regulation of the Layers
STRATOSPHERE
The stratosphere can only absorb energy using ozone (the heat from the Earth really doesn't affect it)
- The stratosphere gets warmer as you go up and move through the ozone layer MESOSPHERE
The mesosphere lacks the ozone layer and is too far away from Earth for the Earth to help warm it up. It is also further from the sun, so the sun does not warm it up much. It is the coldest layer - but the air molecules are dense enough to destroy meteoroids!
THERMOSPHERE
The thermosphere's atoms and molecules absorb the most heat from the sun.
The molecules in the last layer move really fast (temperature = how much molecules move) but they are really far apart from each other, so it would feel cold if you took a space walk.
Hint: In ice (solid water) the particles do not move much, but in liquid water the particles are able to move more - this is because the liquid water has a higher temperature.
The stratosphere can only absorb energy using ozone (the heat from the Earth really doesn't affect it)
- The stratosphere gets warmer as you go up and move through the ozone layer MESOSPHERE
The mesosphere lacks the ozone layer and is too far away from Earth for the Earth to help warm it up. It is also further from the sun, so the sun does not warm it up much. It is the coldest layer - but the air molecules are dense enough to destroy meteoroids!
THERMOSPHERE
The thermosphere's atoms and molecules absorb the most heat from the sun.
The molecules in the last layer move really fast (temperature = how much molecules move) but they are really far apart from each other, so it would feel cold if you took a space walk.
Hint: In ice (solid water) the particles do not move much, but in liquid water the particles are able to move more - this is because the liquid water has a higher temperature.