PNNL

Abstract

The BiLateral Operational Storm-Scale Observation and Modeling (BLOSSOM) project was initiated to establish routine storm-scale polarimetric radar observations and cloud-process modeling at NASA GSFC Wallops Flight Facility (WFF), where various continental and maritime convective systems are observed. The ultimate goals of BLOSSOM are to establish a long-term supersite to improve understanding of cloud physical states and processes as well as to support satellite and climate model programs over the WFF site via a bilateral approach of storm-scale observations and process modeling. This study highlights a noble systematic validation framework of the BLOSSOM ensemble cloud-process simulations through mixed-phase, light-rain, and deep-convective precipitation cases. The framework consists of creating an domain-lagged ensemble of large-scale forcing datasets, and configuring and performing cloud-process simulations with three different bulk microphysics schemes. Validation uses NASA S-band dual-POLarimetric radar (NPOL) observations in the form of statistical composites and skill scores via a polarimetric radar simulator and newly developed CfRad Data tool (CfRAD). This new ensemble-based validation framework is used to demonstrate the impact of spatial resolution on the cloud-process simulations and model skill scores. The results suggest that no particular forcing or microphysics scheme outperforms the rest and that the skill scores of coarse- and fine-resolution ensemble simulations with different domain-lagged forcing and microphysics schemes are highly correlated with each other with no clear improvement. On the other hand, this suggests that coarse-resolution ensemble simulations are relevant for selecting the best meteorological forcing and microphysics scheme before conducting computationally demanding large eddy simulations (LESs) in support of aircraft and satellite instrument development as well as cloud-precipitation-convection parameterizations