High-Frequency Observations of Cyanobacterial Blooms in Lake Taihu (China) from FY-4B/AGRI

China’s FY-4B satellite, launched on 3 June 2021, is a new-generation geostationary meteorological satellite. The Advanced Geosynchronous Radiation Imager (AGRI) onboard has 15 spectral channels, including 2 visible (470 and 650 nm), 1 near infrared (825 shortwave (1379, 1610, 2225 nm) bands, which can be used to observe the Earth system with highest spatial resolution of 500 m min temporal resolution. In this study, FY-4B/AGRI observations were applied for first time monitor cyanobacterial blooms in Lake Taihu, China. AGRI reflectance at near-infrared bands was corrected surface using 6S radiative transfer model. Due similar characteristics those land-based vegetation, normalized difference vegetation index (NDVI) some other remote sensing indices are usually retrieval blooms. fractional cover (FVC) algae, defined as fraction green nadir view, adopted depict status trend NDVI FVC, two developed land detection cyanobacteria Taihu. Finally, FVC derived from measurements compared that obtained Himawari (AHI) Himawari-8 satellite validate effectiveness our method. It found atmospheric correction substantially improve determination values lake. As proof robustness algorithm, NDVIs both AHI their magnitudes similar. addition, distribution highly consistent FY-3D/MERSI EOS/MODIS. While lower might restrict its capability capturing details blooms, high-frequency provide information timely effective management aquatic ecosystems help researchers better quantify understand dynamics particular, greater diurnal variation owing high