The MODIS Cloud Phase Optical Properties layer indicates the phase of cloud particles used in the Cloud Optical Thickness and Cloud Effective Radius retrieval algorithm. This Collection 6 algorithm classifies cloud into 3 phases - ice, water and uncertain. This cloud phase retrieval algorithm shows improved detection of ice clouds, with far few instances of optically thin ice clouds being misclassified as liquid clouds compared to the MODIS Cloud Phase Infrared product, which uses a different retrieval algorithm. Cloud phase plays a key role in regulating the Earth’s energy budget because the sunlight incident on ice and liquid clouds are reflected, absorbed and transmitted very differently. Hence determining the phase of cloud is important to understand the climate feedback mechanism and the Earth’s energy budget.
The MODIS Cloud Phase Optical Properties layer is available from both the Terra (MOD06) and Aqua (MYD06) satellites for daytime overpasses. The sensor/algorithm resolution is 1 km, imagery resolution is 1 km, and the temporal resolution is daily.
References: MODIS Atmosphere - Cloud (06_L2); MODIS Cloud Optical Properties: User Guide for the Collection 6 Level-2 MOD06/MYD06 Product and Associated Level-3 Datasets: July 2018; Cloud Top Properties and Cloud Phase Algorithm Theoretical Basis Document: May 2015