Investigating Instrument-Specific Discrepancies in Cloud and Rain Drop-Size Distributions

Spaceborne radar measurements from CloudSat, the Global Precipitation Measurement (GPM) Core Observatory, and the Tropical Rainfall Measuring Mission (TRMM) offer valuable insights into cloud and rain-drop size distributions. However, their potential remains underutilized due to potentially large uncertainties and instrument-specific limitations. CloudSat primarily detects cloud and drizzle droplets, while GPM and TRMM focus on rain drops, with overlap mainly in moderate rainfall and heavy snow regions. This study aims to explicitly investigate the differences in drop-size distributions observed by these instruments in similar cloud environments. We will compare drop-size distributions using CloudSat's 2C-RAIN-PROFILE exponential distribution and the gamma parameters from GPM and TRMM. Data will be conditioned by cloud regime (MODIS), environment (ECMWF-AUX), and height to identify discrepancies between observations from the same and different instruments. Through this work, our research seeks to highlight observational uncertainties in cloud microphysics, providing a benchmark for comparison against models.