Generating Hourly Continuous Evapotranspiration Using Fengyun‐2F Geostationary Satellite Data

• Published in: Earth and space science (Hoboken, N.J.) Vol. 9; no. 3
• Main Authors: Geng, Xiaozhuang, Li, Boyang, Pan, Xiaoduo, Wei, Zhihao, Yang, Xuebin, Liao, Kuo, Cui, Yaokui
• Format: Journal Article
• Language: English
• Published: Hoboken John Wiley & Sons, Inc 01.03.2022; American Geophysical Union (AGU)
• Subjects: Algorithms; Atmosphere; Clouds; Datasets; Drought; Energy balance; Evapotranspiration; Experiments; Fengyun‐2F; Hydrology; Land surface temperature; Latent heat; Meteorological satellites; Precipitation; Radiation; Rain; Remote sensing; River basins; Satellites; spatio‐temporal continue; TSEB model; Vegetation; Heihe River; China
• ISSN: 2333-5084; 2333-5084
• DOI: 10.1029/2021EA002090

Evapotranspiration (ET) plays an important role in water and energy exchange between the atmosphere and the land surface. ET at regional scale is of great importance in hydrology, meteorology, and agriculture. The remotely sensed land surface temperature (LST)‐based two‐source energy balance (TSEB) model is widely used to monitor ET. However, due to the influence of clouds, the quality of remotely sensed LST products is declined and there are also many gaps in the LST products, which make it very difficult to estimate spatio‐temporally continuous ET based on remote sensing data. In this study, we proposed a method to generate hourly continuous ET using Fengyun‐2F geostationary images. First, the hourly continuous real LST are obtained using a clear‐sky LST reconstruction algorithm and radiometric correction algorithm, and then the reconstructed real LST is used to the estimation of latent heat flux using the TSEB model. The results in the Heihe River Basin show that the proposed method can successfully generate hourly continuous ET compared with three eddy covariance sites with different underlying surface. The estimated ET achieves acceptable performance with RMSE = 81.88 W/m2 and R2 = 0.67 at hourly scale and with RMSE = 1.48 mm/d and R2 = 0.65 at daily scale. We believe this can help the community to better understand the water and energy exchange between the atmosphere and the land surface at fine spatio‐temporal scale, especially on the hourly scale. Key Points Fengyun‐2F (FY‐2F) real land surface temperature (LST) was reconstructed under cloudy condition Spatio‐temporally continuous hourly Evapotranspiration (ET) was obtained by the two‐source energy balance ET model derived by reconstructed FY‐2F real LST Simulated ET is comparable with the observations at hourly and daily scales