The boundary region between the troposphere and the stratosphere is called as:
The tropopause is the boundary in the Earth's atmosphere between the troposphere and the stratosphere.Going upward from the surface, it is the point where air ceases to cool with height, and becomes almost completely dry. More formally, the tropopause is the region of the atmosphere where the environmental lapse rate changes from positive, as it behaves in the troposphere, to the stratospheric negative one.