Evaluation of Climate Model Precipitation Processes using a TRMM/GPM Radar Simulator

Abstract

The Cloud Feedback Model Intercomparison Project (CFMIP) Observation Simulator Package (COSP) will be adapted for Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) and Global Precipitation Measurement (GPM) dual-frequency precipitation radar (DPR) observations and applied to NASA GISS Model-E and other Coupled Model Intercomparison Project Phase 6 (CMIP6) general circulation model (GCM) grid-box output. The COSP sub-grid scale algorithm will be improved to align better with observations. We will comprehensively compare model-simulated observations to satellite-based radar reflectivity of precipitating cloud systems using the above radar simulator. Specifically, we aim to evaluate model fidelity at representing convective and stratiform precipitation processes and pinpoint possible causes for model-observation discrepancies. This research satisfies Section 2.3.2 Methodologies for Climate Model Improvement under Section 2.3 Data and Methodology for Climate Projection Assessment desire for “novel strategies and methodologies to compare results from Earth system models with NASA observations and reanalysis” and the goal to “identify any model systematic errors, associate the errors with model algorithm deficiencies, and pinpoint the necessary model improvements.”