The FengYun (FY) meteorological satellites, equipped with combined microwave and infrared (IR) sensors, provide temperature and humidity profiles under both clear and cloudy conditions, supporting global atmospheric monitoring and weather forecasting. This study evaluates the FY-3E vertical atmospheric sounding system (VASS) using collocated radiosonde observations, reanalysis data, and satellite measurements, including the Cross-Track IR and Microwave Sounder Suite (CrIMSS) onboard joint polar satellite system-1 (JPSS-1). Under all-sky conditions, VASS temperature profiles exhibit a correlation of 0.99 with radiosonde data, and humidity profiles reach 0.80. The temperature biases [root-mean-square errors (RMSEs)] are 0.63K (3.07K) under clear-sky, 0.82K (3.56 K) under cloudy-sky, and 0.67K (3.26K) under all-sky conditions. The corresponding humidity biases (RMSEs) are 4.63% (18.36%), 6.21% (21.38%), and 4.76% (19.36%). Compared with CrIMSS products using coincident radiosonde data, the VASS retrievals show larger errors in both temperature and humidity, yet provide consistent and reliable atmospheric profiles under diverse conditions. These results confirm the current utility of FY-3E VASS in operational weather and climate services while highlighting the need for continued algorithm development to further reduce retrieval uncertainties.

FengYun-3E (FY-3E), humidity, temperature, vertical atmospheric sounding system (VASS)