tropopause

https://doi.org/10.1351/goldbook.T06521
The region of the atmosphere which joins the @T06522@ and @S06043@, and where the decreasing temperature with altitude, characteristic of the @T06522@ ceases, and the temperature increase with height which is characteristic of the @S06043@ begins.
Source:
PAC, 1990, 62, 2167. (Glossary of atmospheric chemistry terms (Recommendations 1990)) on page 2218 [Terms] [Paper]