Forty Years of ISCCP: The Past, Present, and Future of the International Satellite Cloud Climatology Project

The International Satellite Cloud Climatology Project (ISCCP) has aided understanding of the global climate for over four decades. ISCCP’s consistent record has provided invaluable insights into the Earth’s energy budget, hydrological cycle, and the effects of clouds on climate. Since its inception in 1982, ISCCP has evolved substantially over time transitioning from ISCCP-C, to ISCCP-D, to the current ISCCP-H series. ISCCP-D covered the period from July 1983 through December 2009, and ISCCP-H extended the record through June 2017. Throughout its lifecycle, ISCCP has undergone key refinements in quality control measures, heightened spatial resolution, and modernization of file formats. Ongoing efforts are focused to further enhance the ISCCP-H product including: view zenith angle corrections, extending the period of record through 2022, implementing processing improvements and automation, updating ancillary data inputs, conducting thorough quality control checks, and fine-tuning calibration techniques. To better understand the ever evolving field of satellite observations, statistical comparisons of ISCCP processing with AVHRR and VIIRS inputs will also be discussed. A comprehensive view of refinements made to the ISCCP dataset will be presented, as well as future plans for its continued evolution.