Comparison of Cloud-Top Property Retrievals From Advanced Himawari Imager, MODIS, CloudSat/CPR, CALIPSO/CALIOP, and Radiosonde

The information on cloud properties and microphysical characteristics is critical for environmental research and application, such as that on weather, climate, hydrology, and green energy and Earth energy budget. The launch of the new-generation geostationary satellite, for example, the Japanese Himawari-8, enables retrieval of cloud information through multichannel observation. To confirm the retrievals from the Advanced Himawari Imager (AHI) onboard Himawari-8 (Himawari-8/AHI), this study accessed the cloud retrievals from AHI and compare them against those obtained from spaceborne passive and active sensors on the low Earth orbit satellites, such as NASA's CloudSat, Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO). The atmospheric thermodynamic state from in situ radiosonde provides another dimension for evaluating the retrieved cloud-top temperature and height, which were obtained and analyzed during two research cruises over the South China Sea during monsoon onset season with large cloud variability to ensure the comprehensive intercomparisons. The findings show that the cloud-top altitude, cloud optical thickness, and cloud effective particle radius retrieved from AHI are consistent with passive Moderate Resolution Imaging Spectroradiometer (MODIS) data. Furthermore, both spaceborne active Cloud Priofiling Radar (CPR) and Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) data confirm the low uncertainty of cloud-top altitude, particularly when the cloud is optically thick. Large cloud-top altitude discrepancy among these data in the optically thin cloud might be due to the limited AHI spectral channels or instrumental spatial resolutions. The cloud-top temperature and altitudes in either liquid or ice phase cloud agree well with collocated sounding profiles, with low difference of 1 K and 170 m, respectively.