2.2.2. Satellite Data

MOD17A2H (Collection 6) is a standard satellite product with a spatial resolution of 500 m and a temporal resolution of 8 days. It is calculated based on the light use efficiency (LUE) approach by Monteith [31]:

$$\text{GPP} = \varepsilon \times \text{fPAR} \times \text{PAR} \tag{1}$$

where *ε*, fPAR, and PAR denote the radiation use efficiency coefficient (RUE), the fraction of incident PAR absorbed by the surface, and photosynthetically active radiation, respectively [32].

According to Running et al. [32], the GPP values of MOD17A2H refer to the sum of the GPP during an 8-day period. In this study, we averaged the total GPP to generate the 8-day averaged GPP.
