Definition - What does Tropopause mean?
Tropopause is a thin layer of air in the atmosphere forming a soft boundary in the Earth's atmosphere between the troposphere and the stratosphere. It lies at about 8000 meter or lower near the poles and gradually increases in height about 18000 meter or above as it approaches the equator. This is the highest level of world’s weather activity.
Safeopedia explains Tropopause
The height of the tropopause is variable with the latitude of the location and the seasons. Higher the latitude, lower the height. In summer tropopause rises up and lows down in winter. This is the highest level of atmosphere where the weather activities occur. Temperature in tropopause is about -80 °C. Most commercial aircraft fly just above the tropopause, where there is no cloud.