Here's why:
* Troposphere: The troposphere is the lowest layer of the Earth's atmosphere, where weather occurs. It's characterized by decreasing temperature with increasing altitude.
* Tropopause: The boundary between the troposphere and the stratosphere is called the tropopause.
* Cirrus Clouds: Cirrus clouds are wispy, feathery clouds made of ice crystals. They form at high altitudes, typically in the upper troposphere or lower stratosphere.
Since cirrus clouds form at the top of the troposphere, they are often a good indicator of the tropopause's location. However, keep in mind that the tropopause's altitude varies with latitude and season.
