The effect of imposed stratospheric cooling on tropical cyclone potential intensity in axisymmetric simulations

There has been considerable debate over the role of increasing sea surface temperatures (SST) on tropical cyclone (TC) intensity globally. However, according to TC potential intensity (PI) theory, SST is only one factor governing the thermodynamic environment of a TC; the other being the temperature of the entropy-weighted outflow layer – the so-called ‘outflow temperature'. The extent to which the outflow temperature has contributed to past trends in TC intensity remains unclear, though some recent studies suggest it could be a significant factor. In this study, the effect of lower-stratospheric cooling on PI is quantified using an axisymmetric cloud model run in an idealized mode of radiative-convective equilibrium. Preliminary results indicate a close match between the simulated increase in PI and the trend derived from reanalysis data. The physical mechanisms behind the model-based trends are being investigated.