What are the major layers of the atmosphere?

There are many layers of the atmosphere. There is a lot of difference in their properties.

1. Troposphere - The lowest layer of the atmosphere is called troposphere. 'Tropo' means changing. Hence, Troposphere is that layer in which the temperature changes upward on account of convection current. Height - 16km at the equator and 7 km at the poles. It contains most the atmospheric air (75%).

2. Stratosphere - Lies above Tropopause (the imaginary line between troposphere and stratosphere). The temperature in the lower part of this sphere does not change with altitude. The temperature is nearly constant upward about 20km and then increases, owing to absorption of ultraviolet radiation by ozone.

3. Ionosphere - The ionosphere is defined as the layer of the Earth's atmosphere that is ionized by solar and cosmic radiation. It lies 75-1000 km (46-621 miles) above the Earth. Free electrons in this layer help in the conduction of electricity in this sphere.

4. Mesosphere - The mesosphere starts at 50 km (31 miles) above Earth's surface and goes up to 85 km (53 miles) high. As you get higher up in the mesosphere, the temperature gets colder. The top of the mesosphere is the coldest part of Earth's atmosphere.

5. Exosphere - The exosphere is the uppermost region of Earth's atmosphere as it gradually fades into the vacuum of space. Air in the exosphere is extremely thin - in many ways, it is almost the same as the airless void of outer space.

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here are the layers of the atmosphere going upwards

• Troposphere
• Stratosphere
• Mesosphere
• Thermosphere
• Exophere

check out the following graphical representation

source: http://ete.cet.edu/gcc/?/volcanoes_layers/

this article gives a detailed explanation about the layers of the atmosphere
http://www.vtaide.com/png/atmosphere.htm

There are 5 atmospheric Layers.

Troposphere:
Starts at 8 km above the Earth's surface to 14.5 km. Weather occurs in this layer.

Stratosphere:
Starts above 14.5 km and ends at 50 km. Jet planes fly in this layer.

MesoSphere:
Starts above 50km and ends at 85 km. Meteors disintegrate in this layer.

Thermosphere:
Starts above 85 km and ends at 600 km. Satellites are found in this layer.

Exosphere:
Starts above 600 km and extends to 10000 km. This is the Top layer of are atmosphere.

100 km above the Earth's surface marks the Start of Space called the Karaman Line