What distinguishes the troposphere from the stratosphere?

The troposphere is distinguished from the stratosphere by its weather phenomena and decreasing temperature with altitude.

The troposphere is the lowest layer of Earth's atmosphere, extending from the surface to about 8 to 15 kilometres high, depending on the latitude and season. This layer is characterised by its weather phenomena, such as clouds, rain, snow, and storms, which are driven by the heat from the sun warming the Earth's surface. The temperature in the troposphere decreases with altitude, which is a phenomenon known as the lapse rate. This is because the majority of the sun's heat is absorbed by the Earth's surface, which then warms the air above it. As you move higher in the troposphere, the air becomes less dense and cooler.

On the other hand, the stratosphere is the second layer of the Earth's atmosphere, located above the troposphere and below the mesosphere, extending from about 15 to 50 kilometres above the Earth's surface. Unlike the troposphere, the temperature in the stratosphere increases with altitude. This is due to the presence of the ozone layer, which absorbs the sun's harmful ultraviolet radiation and converts it into heat. This warming trend with altitude makes the stratosphere stable, with little vertical mixing of air masses, which is why weather phenomena do not occur in this layer.

Furthermore, the boundary between the troposphere and the stratosphere, known as the tropopause, also distinguishes these two layers. The tropopause acts as a barrier that prevents the mixing of air between the troposphere and the stratosphere. This is because the temperature inversion at the tropopause (where the temperature stops decreasing with height and starts increasing in the stratosphere) creates a stable layer that inhibits vertical air movement.

In summary, the troposphere and the stratosphere are distinguished by their temperature trends with altitude, the occurrence of weather phenomena, and the presence of the tropopause. Understanding these differences is crucial for studying Earth's climate system and predicting weather patterns.