Quantifying the Differences in Southern Ocean Clouds Observed by Radar and Lidar From Three Platforms

Abstract A synergistic analysis of the radar‐only and combined radar‐lidar observations across the three platforms was conducted. To align with well‐calibrated CloudSat cloud profiling radar (CPR) (and HCR) reflectivity measurements, a constant 4.5 dB offset was applied to all M‐WACR reflectivitives during the MARCUS. This brings M‐WACR data into better agreement with both HCR and CPR reflectivity measurements and facilitates a more reliable cloud fraction (CF) comparison. The total CFs (CF T s) derived from the three radars show excellent agreement. All three radars detect large drizzle drops, but M‐WACR and HCR excel at detecting smaller cloud droplets that are often missed by CPR. The underestimated CFs by CPR are due to increased attenuation of CPR measurements below 3 km, and the combined effects of attenuation and surface clutter below 1 km. Combining radar and lidar observations enhanced cloud detection by 20%–60%. The results from this study provide new insights for designing future cloud radar systems.