Good Things Need Time: Progress With the First Hyperspectral Sounder in Geostationary Orbit

Abstract

My comments address the Geostationary Interferometric Infrared Sounder (GIIRS) on the Chinese FY-4A satellite. It is the first hyperspectral sounder in geostationary orbit. An impact study by Yin et al. (2021, https://doi.org/10.1029/2021GL093672) of GIIRS data on forecasting of typhoon (Maria in 2018) shows beneficial results. GIIRS provides temperature and humidity observations in cloud-free areas with high vertical and, as a novelty, with high temporal resolution (as short as 15 min) over a limited area. The development of GIIRS was long preceded by international plans and it will be followed by other hyperspectral sounders covering the geostationary ring. GIIRS is a major step toward an improved global space-based observing system enabling better forecasts of the temporal evolution of severe convective weather.