## 3 Results
### Magnitude and Patterns of Annual GPP  
The annual GPP based on the universal SIF-GPP relationship (site-level, with intercept) exhibited expected magnitude and spatial pattern across the globe (Figure 6). The highest values of annual GPP were observed in the tropical regions (2500-3500 g C m\({}^{-2}\) yr\({}^{-1}\)), intermediate values in the eastern United States and southern Asia (1000-2000 g C m\({}^{-2}\) yr\({}^{-1}\)), and the lowest values in the sparsely vegetated regions (0-500 g C m\({}^{-2}\) yr\({}^{-1}\)). We then examined how the universal versus biome-specific nature of the SIF-GPP relationship affected the GPP estimates derived from SIF. Figure 7a shows that the difference in annual GPP based on a universal versus biome-specific relationship was generally small across the globe. Relatively large differences were only observed in some highly productive tropical regions and some high-latitude regions. We also examined how the use of the non-zero intercept versus zero intercept influenced GPP estimates for the universal SIF-GPP relationship (site-level). Compared to the use of the zero-intercept, the use of a non-zero intercept resulted in higher annual GPP in regions with low productivity (Figure 7b), indicating that the magnitude of GPP estimates could be significantly influenced by whether the intercept is forced to be zero. Figure 5: Comparison between the coarse-resolution GPP maps (8-day, 1\({}^{\circ}\)) and our finer-resolution GOSIF GPP maps (0.05\({}^{\circ}\)) over (**a**) United States, (**b**) Australia, and (**c**) East Asia for four seasons in 2016. We provided the second 8-day GPP map in January, April, July, and October, representing the four seasons, respectively. The coarse-resolution GPP maps (1\({}^{\circ}\)) were converted from coarse-resolution SIF estimates that were directly averaged from discrete SIF soundings acquired in the nadir mode, and the conversion from SIF to GPP was based on the site-level, universal SIF-GPP relationship (slope = 20.04, intercept = 0.89 g C m\({}^{-2}\) day\({}^{-1}\)/W m\({}^{-2}\)\(\mu\)m\({}^{-1}\) sr\({}^{-1}\); Table 1). Figure 6: Spatial patterns and magnitude of global annual GPP (0.05\({}^{\circ}\) resolution) estimated from GOSIF based on the universal SIF-GPP relationship (site level, with intercept) over the period 2001–2017. Figure 7: Examples of differences in annual GPP estimates based on different SIF-GPP relationships in 2017. (**a**) is the absolute value of the difference between GPP based on the universal SIF-GPP relationship with intercept and GPP based on the biome-specific relationship with intercept, indicating how the universal or biome-specific relationship affected the annual GPP; (**b**) is the absolute value of the difference between GPP based on the universal SIF-GPP relationship with intercept and GPP based on the universal relationship without intercept, indicating how the intercept affected the estimated annual GPP. Note, all relationships shown here were derived from the site level as examples. To account for the uncertainty in GPP estimates resulting from different forms of SIF-GPP relationships (i.e., universal and biome-specific, with and without intercept), we used the eight SIF-GPP relationships to map GPP globally from GOSIF. The magnitude and spatial pattern of mean annual GPP calculated from the ensemble GPP estimates (Figure 8a) were very similar to those based on the site-level, universal SIF-GPP relationship (Figure 6). The standard deviation of annual GPP (Figure 8b) showed that the eight SIF-GPP relationships led to the largest variability in GPP in the tropical regions with high productivity. This discrepancy of annual GPP among the ensemble estimates exhibited clear latitudinal patterns (Figure 8c). The tropics (\(-15\)\({}^{\circ}\)S to \(15^{\circ}\)N) had the largest variability in annual GPP among the eight sets of estimates. The maximum GPP, which shows the seasonal peak of vegetation photosynthesis, captured the typical crop planting areas worldwide (Figure S5).