I'm an expert in atmospheric science with extensive knowledge about the Earth's atmosphere and its various layers. The Earth's atmosphere is a complex and dynamic system that plays a crucial role in supporting life on our planet. It is composed of several layers, each with distinct characteristics and functions. Let's delve into the details of these layers, starting from the one closest to the Earth's surface and moving upwards.

The Troposphere
The troposphere is the lowest layer of the atmosphere, extending from the Earth's surface to approximately 8 to 15 kilometers above sea level, depending on the latitude. This is the layer where we live and where all weather phenomena occur. The troposphere is characterized by a decrease in temperature with altitude, which is known as the environmental lapse rate. It contains about 75% to 80% of the atmosphere's mass and almost all of its water vapor and aerosols. The troposphere is also where most of the Earth's heat is exchanged with the surface through processes such as convection.

The Stratosphere
Above the troposphere lies the stratosphere, which extends from about 15 to 50 kilometers above the Earth's surface. The stratosphere is distinguished by an increase in temperature with altitude, primarily due to the presence of the ozone layer, which absorbs ultraviolet (UV) radiation from the sun. This layer is stable and does not experience the turbulent weather patterns found in the troposphere. The ozone layer is crucial for life on Earth as it protects us from harmful UV radiation.

The Mesosphere
The mesosphere is the third layer of the atmosphere, located above the stratosphere and extending from about 50 to 85 kilometers above the Earth's surface. In this layer, the temperature decreases with altitude again. The mesosphere is home to some of the highest clouds in the atmosphere, known as noctilucent clouds, which are composed of ice crystals. It is also the layer where meteors typically burn up upon entering the Earth's atmosphere.

The Thermosphere
The thermosphere is the fourth layer, starting at around 85 kilometers and extending to between 600 to 800 kilometers above the Earth's surface. Here, the temperature increases dramatically with altitude due to the absorption of high-energy solar radiation by the sparse gas molecules. This layer is the source of the auroras, as charged particles from the sun interact with the Earth's magnetic field and atmosphere. The thermosphere also contains the ionosphere, which plays a vital role in radio communication by reflecting radio waves back to Earth.

The Exosphere
Finally, the exosphere is the outermost layer of the atmosphere, beginning at the top of the thermosphere and extending into space. It is a tenuous layer where the atmosphere gradually fades into space. The exosphere contains very few gas molecules, and these molecules can escape into space due to the lack of gravitational pull. This layer effectively marks the boundary between Earth's atmosphere and outer space.

In conclusion, the five layers of the atmosphere, in order from the Earth's surface to outer space, are the troposphere, stratosphere, mesosphere, thermosphere, and exosphere. Each layer plays a unique role in the Earth's atmospheric system and contributes to the complex interactions that sustain life on our planet.

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The atmosphere is comprised of layers based on temperature. These layers are the troposphere, stratosphere, mesosphere and thermosphere. A further region at about 500 km above the Earth's surface is called the exosphere.read more >>