Using CloudSat Cloud-Top Height Observations to Verify Himawari-8 Infrared Height Assessment

Calculating cloud top height using infrared satellite data is difficult, as is the process of verifying the results. CloudSat is consistently cited as the most accurate source of objective cloud height observations, even given the spatial and temporal limitations of its polar orbiting path. This study uses the Japan Meteorological Agency's geostationary weather satellite, Himawari-8, as the basis for real-time cloud top height analysis. A different method of calculating cloud top height using multispectral infrared brightness temperatures and numerical weather model atmospheric profiles is presented. The multispectral analysis combines traditional infrared channels with water vapor channels to better match the cloud height, especially for optically thin cirrus clouds which often appear warmer (and therefore lower in height) in long-wave infrared channels as opposed to medium-wave water vapor channels. The results of this method are verified against other methods to determine which is most accurate. Statistical analysis of the success rate and error of these methods is compared and contrasted for an observation time using historical CloudSat data from 2018. Finally future work, including utilizing machine learning and AI to improve the detection and classification of clouds and their subsequent height is discussed.