What is the basis for dividing the atmosphere into four layers?

The atmosphere is divided into four main layers: the troposphere, stratosphere, mesosphere, and thermosphere. This division is based on the temperature characteristics of these layers.

1. Troposphere: This is the layer closest to the Earth's surface, where we live. It extends up to about 8-15 kilometers above the Earth. The temperature in this layer decreases with altitude. Most of the Earth's weather occurs in the troposphere.

2. Stratosphere: Above the troposphere is the stratosphere, which extends up to about 50 kilometers above the Earth. Unlike the troposphere, the temperature in the stratosphere increases with altitude. This is due to the absorption of solar radiation by the ozone layer, which is located in this layer.

3. Mesosphere: Above the stratosphere is the mesosphere, which extends up to about 85 kilometers above the Earth. In this layer, the temperature decreases with altitude. This is the layer where most meteors burn up upon entering the Earth's atmosphere.

4. Thermosphere: The outermost layer of the Earth's atmosphere is the thermosphere, which extends from about 85 kilometers to up to 600 kilometers above the Earth. In this layer, the temperature increases with altitude. This is due to the absorption of high-energy solar radiation.

In summary, the basis for dividing the atmosphere into these four layers is primarily their temperature characteristics and the changes in temperature with altitude.