Tropical Tropopause Changes Simulated in CMIP6 Models

Tropical tropopause layer plays a pivotal role in the interaction between the stratosphere and the troposphere. Its thermal structure affects both stratosphere and troposphere via various radiative, dynamic and thermodynamic processes. While GCMs generally predict a warmer tropopause following a warmer surface, the longitudinal and vertical distributions of such warming has been paid less attention. Recent studies identify a failure of most climate models in simulating the recent surface warming pattern. It is then of interest to investigate whether this so-called "pattern effect" impact changes at the tropopause. We compare the AMIP simulations with the observed SST prescribed against those with coupled ocean over the historical period from the CMIP6 archive. We will also compare the tropopause changes following the recent surface warming patterns to those following an ENSO event.