A Modern Approach to a Stability-Based Definition of the Tropopause

Abstract Definition of the tropopause has remained a focus atmospheric science since its discovery near beginning twentieth century. Few universal definitions (those that can be reliably applied globally and to both common observations numerical model output) exist many with unique limitations have been developed over years. The most commonly used definition is temperature lapse-rate established by World Meteorological Organization (WMO) in 1957 (the LRT). Despite widespread use, there are recurrent situations where LRT fails identify tropopause. Motivated increased availability coincident stability composition, this study seeks reexamine relationship between composition change transition layer areas for improvement stability-based In particular, long-term (40+ years) balloon temperature, ozone, water vapor from six locations across globe covariability several metrics composition. We found vertical gradient potential superior metric greatest layer, which we use propose new universally applicable (PTGT) definition. Application reanalysis output reveals PTGT largely agrees LRT, but more identifies tropopause-level when two differ greatly. Significance Statement provide review existing (and their limitations) investigate using balloon-based This work motivated need correct identification accurately assess upper-troposphere–lower-stratosphere processes, turn far-reaching implications our understanding Earth’s radiation budget climate. result research creation new, tropopause: (PTGT).