The Earth's atmosphere can be divided into distinct spherical layers separated by narrow transition zones, and are defined by differences in chemical composition and temperature gradients
Layer Name | Height | Comment | |
---|---|---|---|
Equator | Poles | ||
Troposphere | 0-17 km | 0-10 km | Contains the majority of the air, weather systems are found here, temperature ranges from an average of 14°C at ground level to -52°C |
Tropopause | - | - | Marks the boundary between the troposphere & stratosphere |
Stratosphere | 17-50 km | 8-50 km | In this layer temperature increases as altitude increases, from -52°C to -3°C due to the absorption of UV radiation |
Ozone layer | - | - | Found in the stratosphere absorbs certain wavelengths of UV radiation, UV-A & UV-B. This helps to regulate planetary temperature and helps reduce the UV radiation from damaging DNA molecules in living things causing cancer. |
Stratopause | - | - | Marks the boundary between the stratosphere & mesosphere |
Mesosphere | 50-85 km | Temperature decreases in this layer as altitude increases, falling to -94°C at the top of the layer | |
Mesopause | - | - | Marks the boundary between the mesosphere & thermosphere |
Thermosphere | 80 to ~640 km | The temperature in this layer rises with altitude again, rising to as high as 1727°C depending on solar activity. This is due to the absorption of solar radiation by the remaining oxygen molecules | |
Exosphere | 600 km onwards blends into space | Transition layer between the outermost reach of the atmosphere and interplanetary space, extremely low density of molecules. |
Related: Air Composition