tropopause
Tropopause - a layer of Earth's atmosphere about 1-2 km thick, forming a transition zone between the troposphere and the stratosphere. The poles extend at a height of about 6-8 km, in temperate ranges to 10-12 km, and above the equator rises to 15-17 km. Its location also depends on the time of year - the summer is higher. The temperature in this layer reaches -55 ° C.