The historical climate trend resulted in changed convective transport patterns in model simulations

Abstract. Convective transport leads to a rapid vertical redistribution of tracers. This has a major influence on the composition of the upper troposphere, a highly climate sensitive region. It is not yet clear how the convective transport is affected by climate change. In this study, we applied a new tool, the so-called convective exchange matrix, in historical simulations with the EMAC (ECHAM/MESSy Atmospheric Chemistry) chemistry-climate model to investigate the trends in convective transport. The simulated deep convection is penetrating higher but occurs less frequently from 2011 to 2020 than from 1980 to 1989. The increase in the vertical extend of convection is highly correlated to a rise in the tropopause height. Overall, convection transports material less efficient to the upper troposphere, but the transport directly into the tropopause region has on average increased from 2011 to 2020 in comparison to the 1980ies. These findings give rise for new opportunities to investigate long term simulations performed by EMAC with regard to the effects of convective transport. Further, they might provide a first insight into the trends of atmospheric convective transport due to changing atmospheric conditions and might serve as an estimate for the convective feedback to climate change.