The Earth's atmosphere is divided into distinct layers, each with its own characteristics in terms of temperature, pressure, and composition. These layers, from the Earth's surface outward, are:
1. **Troposphere:**
- **Altitude:** Extends from the Earth's surface up to an average of about 8-15 kilometers (5-9 miles).
- **Temperature:** Generally decreases with altitude.
- **Weather Events:** Virtually all weather events, including clouds, precipitation, and storms, occur in this layer.
2. **Stratosphere:**
- **Altitude:** Extends from the top of the troposphere to about 50 kilometers (31 miles).
- **Temperature:** Temperature increases with altitude due to the presence of the ozone layer.
- **Ozone Layer:** Contains the ozone layer, which absorbs and scatters ultraviolet (UV) solar radiation.
3. **Mesosphere:**
- **Altitude:** Extends from the top of the stratosphere to about 85 kilometers (53 miles).
- **Temperature:** Temperature decreases with altitude.
- **Thermosphere:**
4. **Thermosphere:**
- **Altitude:** Extends from the top of the mesosphere to about 600 kilometers (373 miles) or more.
- **Temperature:** Temperature increases significantly with altitude due to the absorption of high-energy solar radiation.
- **Ionization:** The outer layer of the thermosphere contains a small percentage of ionized particles, contributing to the ionosphere.
5. **Exosphere:**
- **Altitude:** The outermost layer, extending from the top of the thermosphere to the edge of space.
- **Transition to Space:** The exosphere marks the transition from Earth's atmosphere to outer space.
- **Sparse Gases:** Gases in this layer are extremely sparse, and individual molecules can travel hundreds of kilometers before colliding with one another.
These layers are separated by boundaries known as "pauses," where the temperature either levels off or undergoes a significant change. The main pauses are the tropopause (between the troposphere and stratosphere), stratopause (between the stratosphere and mesosphere), and mesopause (between the mesosphere and thermosphere).
The structure of the atmosphere is crucial in understanding atmospheric processes, weather patterns, and climate dynamics. Each layer has distinct characteristics that influence the behavior of gases, the transmission of sunlight, and the distribution of temperature and pressure. The interaction between these layers plays a critical role in shaping Earth's climate and supporting life on the planet.