*2.5. MODIS Data*

Remotely sensed GPP data obtained from the MODIS sensor onboard the Terra satellite were used. These data were calculated based on the concept of light use efficiency [47], through the relation between incident photosynthetically active radiation (PAR), the fraction of photosynthetically active radiation absorbed by plants (FPAR) and the actual light use efficiency (ε) of vegetation [49]:

$$\text{GPP} = \varepsilon \text{ } \ast \text{ APAR} \tag{6}$$

where APAR is the absorbed photosynthetically active radiation, which is calculated as the product between the FPAR—derived from the MOD15A2H product [50]—and the PAR. PAR values are obtained from the Global Modeling Assimilation Office (GMAO) reanalysis [51] set and correspond to 45% of the total incident solar energy in the visible spectrum (0.4 to 0.7 μm). In the MOD17A2 product, the values of ε are derived from the attenuation of its maximum value (εmax) due to two environmental stresses: (1) minimum temperature (Tmin), which can inhibit photosynthesis, reducing enzymatic activity, and (2) vapor pressure deficit (VPD), because high VPD can reduce stomatal conductance [52]. The GPP data for the Caatinga biome were derived from the MOD17A2 version 6.0 product [53] from the MODIS sensor on board the Terra satellite. This algorithm provides 8-day composite data in a 500 m spatial resolution.

Reanalysis data from the GMAO dataset (https://gmao.gsfc.nasa.gov/GMAO\_products/ reanalysis\_products.php, accessed on 25 February 2022) used as input parameters for the MOD17A2 product were Tmin and VPD. Therefore, we carried out an overall assessment to check for inconsistencies in this dataset in relation to the same parameters measured at the Cerrado, Caatinga, Pantanal and Amazon biomes. FPAR and leaf area index (LAI) data from the MOD15A2H product were also verified. Furthermore, the MOD12 product [54] for land cover was also discussed regarding the years 2014 and 2015 in the region.

The MOD12 [54] product for land cover was also discussed regarding the Cerrado and Caatinga site for the period from 1 January 2014 to 31 July 2015, the Pantanal site for the period from 1 January 2015 to 31 December 2016, and the Amazon site from 1 January 2009 to 31 December 2011.
