A GEO-Ring of Spectral Radiances: Toward a Next Generation of the International Satellite Cloud Climatology Project (ISCCP-NG)

Abstract Since 2014, space agencies have launched advanced meteorological imagers into the geostationary (GEO) orbit encircling Earth’s equator, known as the GEO-Ring. JMA, NOAA, and KMA launched imagers measuring 16 spectral bands with thermal resolutions of 2 km and full-disk coverage every 10 min. China Meteorological Administration’s (CMA’s) Fengyun-4A ( FY-4A) series, launched in 2016, observes 14 bands with 4-km thermal resolution and 15-min full-disk scans. In 2022, EUMETSAT introduced the Meteosat Third Generation (MTG) imager, offering 16 channels, 2-km thermal resolution, and 10-min full-disk coverage. Together, these satellites provide near-global coverage with improved capabilities over earlier generations. The 10–12 common channels across the latest imagers enable retrieval of diverse atmospheric variables at high temporal resolution. These data represent a substantial advance beyond the early 1980s when the International Satellite Cloud Climatology Project (ISCCP) was first developed. The challenge facing any new GEO-Ring project, such as one being planned as part of a next generation of ISCCP (ISCCP-NG), is to define a new baseline from these measurements and processing methods to extract meaningful information for the scientific community in the coming decades. This paper outlines the design of a GEO-Ring radiance project to support a future ISCCP-NG and many other applications and emphasizes the benefits compared to the B1 and B3 data used in ISCCP. Significance Statement Space agencies have made large investments in improving the capabilities of the geostationary (GEO) meteorological satellite imagers surrounding Earth’s equator in the so-called GEO-Ring. To facilitate the use of these data for scientific studies by a wide community, the Global Energy and Water Exchanges project (GEWEX) Data and Analysis Panel (GDAP) initiated a next generation of the International Satellite Cloud Climatology Project (ISCCP-NG). The original and pioneering ISCCP was formed when the first generation of the GEO-Ring was established in the early 1980s. This paper demonstrates the development of the new GEO-Ring dataset and how it may lead to an ISCCP-NG. The characteristics of the GEO-Ring data are described and their application to cloud, aerosol, and storm-tracking applications are illustrated.