Huaize Feng, Tongren Xu, Jingxue Zhao, Xinlei He, Shaomin Liu

Successfully applied in the carbon research area, sun-induced chlorophyll fluorescence (SIF) has raised the interest of researchers from the water research domain. However, the mechanism between SIF emitted by plants and transpiration (T) has not been fully explored. To improve the understanding of the relationship between SIF and T, we developed two SIF-T models, the WUE model and the conductance model, based on carbon-water coupling framework. Hourly data were used to build and validate the models we developed. Correlation analysis shows that the T modeled by our model outperforms the traditional empirical linear model with higher R2 and lower RMSE. The models we built further show the potential and mechanism in estimating water flux by SIF.