Using Synthetic Satellite Observations to Evaluate the Performance of Planetary Boundary Layer and Cloud Microphysical Parameterization Schemes in Convection-Permitting Model Simulations

In this study, the ability of several cloud microphysical and planetary boundary layer parameterization schemes to accurately simulate cloud characteristics within 4-km-grid-spacing ensemble forecasts over the contiguous U.S. was evaluated through comparison of simulated synthetic GOES infrared brightness temperatures with real observations. Four double-moment microphysics schemes and five planetary boundary layer (PBL) schemes were evaluated. Large differences were found in the simulated cloud cover, especially in the upper troposphere, when using different microphysics schemes. Overall, the results revealed that the two microphysics schemes that predicted two moments of all five cloud-hydrometeor species tended to produce too much upper level cloud cover, whereas simpler schemes did not contain enough high clouds. Smaller differences occurred in the cloud fields when using different PBL schemes, with the greatest spread in the ensemble statistics occurring during and after daily peak heating hours. Results varied somewhat depending upon the verification method employed, which indicates the importance of using a suite of verification tools when evaluating high-resolution model performance. Finally, the large differences between the various microphysics and PBL schemes indicate that there remains large uncertainty in how these schemes represent subgrid-scale processes affecting the forecast cloud fields.