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.