Evaluation of the Super-Droplet Method for Enhanced Cloud Microphysics Simulations of Deep Convective Clouds

Accurate simulation of cloud microphysics is essential for reliable weather forecasting and understanding aerosol-cloud interactions. This research focuses on the Super-Droplet Method (SDM), a particle-based numerical microphysical scheme integrated into the SCALE library of weather and climate models. The aim is to enhance its performance in simulating deep convective clouds and cloud clusters, particularly those generating heavy rainfall.

In comparison to traditional schemes such as bulk and bin models, the SDM provides a more efficient approach to simulating cloud microphysics. Previous simulations of cumulonimbus clouds using SDM have demonstrated its ability to capture crucial cloud processes, including vertical development, updrafts, downdrafts, and various ice morphologies. Despite its detailed representation of cloud microphysics, SDM requires less computational power than multi-dimensional bin schemes.

Data from the Cloud Aerosol Interaction and Precipitation Enhancement Experiment (CAIPEEX) conducted by the Indian Institute of Tropical Meteorology (IITM) are now employed to assess and refine the SCALE-SDM model.

Our preliminary analysis compared radar-derived hydrometeor proportions with those from SDM. The results suggest SDM results align well with radar observations. An iterative approach, involving multiple simulations, validated the reliability of our findings and identified areas for further SDM refinement.

Further validation included comparing simulated data from SCALE-SDM and conventional models with in-situ aircraft measurements and polarimetric Doppler radar data. Preliminary results indicate a consistency between the SCALE-SDM model and observational data. Within the parameters preliminarily tested, the structure of cumulonimbus clouds was found to be influenced by concentrations of mineral dust and hygroscopic aerosols, although precipitation was less affected.

In conclusion, the enhancements made to the Super-Droplet Method, as presented in this research, underscore its potential for precise cloud simulations.