Process-Oriented Diagnostics for Tropical Cyclones and Disturbances in Climate Models Using the Column-Integrated Moist Static Energy Variance Budget

General circulation models (GCMs) and reanalyses struggle to accurately represent TCs and have biases in the TC frequency and intensity distributions. By employing the column-integrated moist static energy (MSE) variance budget as a process-oriented diagnostic, we can analyze the model representation of physical processes that help or hinder the development of TCs. Specifically, we analyze the radiative and surface flux feedback terms within the MSE variance budget across 5 different reanalysis datasets and 18 different GCM simulations. Compositing TC snapshots by maximum velocity and minimum sea level pressure allows for comparison across the GCMs and reanalyses of the feedbacks at a given intensity, as well as an examination of how the feedbacks vary with storm intensity. We find that the surface flux feedback on TC development is weaker in coupled models than in those that are uncoupled. Ocean coupling also influences radiative feedbacks, because the TC-induced sea surface temperature (SST) cooling reduces the surface upward longwave radiative flux. Across all models, the longwave radiative feedback positively contributes to TC development and is driven by cloud effects. Models differ regarding the role of the shortwave radiative feedback, though it is generally smaller than the longwave. When comparing models and reanalyses to CloudSat observations, we find that the CloudSat radiative feedbacks do not vary as much with intensity. Regarding the intermodel spread in surface flux and radiative feedbacks at a given intensity, models with coarse resolution (about half a degree or greater) differ more from each other and from reanalyses than those with high resolution (finer than half a degree). These results can help us understand how differences in model representation of physical processes lead to model differences in TC intensity. We also present preliminary results from developing similar process-oriented diagnostics for tropical disturbances in the ERA-5 reanalysis dataset. We compare the MSE variance budget in those disturbances that develop into TCs to those that do not.