What layer is referred to as the lowest layer of Earth's atmosphere?

The troposphere is identified as the lowest layer of Earth's atmosphere, extending from the surface of the Earth up to about 8 to 15 kilometers above sea level, depending on geographic location and weather conditions. This layer is crucial because it is where nearly all weather phenomena occur, including clouds, rain, and storms. The temperature in the troposphere generally decreases with altitude, resulting in cooler temperatures at higher elevations.

Additionally, the troposphere contains the highest concentration of air molecules, meaning it also has the highest density of air in comparison to the other layers of the atmosphere. This makes it the most influence on life on Earth since it provides the air we breathe and is essential for weather systems. The processes that occur in this layer, such as convection and the formation of atmospheric circulation patterns, are fundamental for understanding climate and meteorological conditions.

In contrast, the other layers—stratosphere, mesosphere, and thermosphere—are located above the troposphere and have distinct characteristics and functions. For instance, the stratosphere contains the ozone layer, which absorbs and scatters ultraviolet solar radiation, while the thermosphere is known for its high temperatures and is where the auroras occur.