A study of warm rain detection using A-Train satellite data

Warm rain occurs in low-level liquid water clouds and does not involve an ice-phase process. Comprising many state-of-the-art passive and active instruments, the NASA A-Train series of satellites provide comprehensive simultaneous information about warm clouds and their precipitation processes. This study exploits multi-sensor data from the A-Train satellite constellation to investigate the rain contribution from warm clouds and the potential of using cloud microphysical parameters for warm rain detection. It is shown that warm rain accounts for a significant portion of total precipitation over the global ocean. Cloud microphysical parameters (e.g., liquid water path) show potential for detecting warm rain events and estimating the rain rates. Key parameters for estimating warm rain using cloud microphysical parameters are also examined.