# Increasing Ecosystem Fluxes Observed from Eddy Covariance and Solar-Induced Fluorescence Data
## 3 Results
### Spatiotemporal Variations in Global WUE  
We further explored spatiotemporal variations in WUE (=GPP/ET) for ECSIF products on the global scale (Figure 7). High WUE (>2 g C kg\({}^{-1}\) H\({}_{2}\)O yr\({}^{-1}\)) was found mainly in \begin{table}
\begin{tabular}{c c c c c c c} \hline
**Variables** & **Methods** & **Global** & **Temporal** & **Spatial** & **Temporal** & **References** \\  & & & **Cover** & **Resolution** & **Resolution** & **References** \\ \hline \multirow{8}{*}{GPP} & BESS & 122 \(\pm\) 25 Pg C yr\({}^{-1}\) & 2000–2015 & 1 km & 8 day & [PERSON] and [PERSON] [16] \\  & BEPS & 124 \(\pm\) 4 Pg C yr\({}^{-1}\) & 1982–2016 & 0.5\({}^{\circ}\)\(\times\) 0.6\({}^{\circ}\) & hourly & [PERSON], et al. [68] \\  & & 485 \(\pm\) 8 mm yr\({}^{-1}\) & & & & \\ GPP & PML-V2 & 145.8 Pg C yr\({}^{-1}\) & 2002–2017 & 500 m & 8 day & [PERSON] et al. [5] \\  & & 560 mm yr\({}^{-1}\) & & & & \\  & X-BASE & 124.7 \(\pm\) 2.1 Pg C yr\({}^{-1}\) & 2001–2020 & 0.05\({}^{\circ}\)\(\times\) 0.05\({}^{\circ}\) & hourly & [PERSON] et al. [44] \\  & & 574 \(\pm\) 7 mm yr\({}^{-1}\) & & & & \\  & SIF-ML & 128 \(\pm\) 2.3 Pg C yr\({}^{-1}\) & 2001–2020 & 0.05\({}^{\circ}\)\(\times\) 0.05\({}^{\circ}\) & 8 day & This study \\  & & 522 \(\pm\) 58.2 mm yr\({}^{-1}\) & & & & \\ \hline \multirow{8}{*}{GPP} & EC-LUE & 111 \(\pm\) 21 Pg C yr\({}^{-1}\) & 2000–2003 & 0.5\({}^{\circ}\)\(\times\) 0.6\({}^{\circ}\) & 8 day & [PERSON], et al. [8] \\  & BEPS & 132 \(\pm\) 22 Pg C yr\({}^{-1}\) & 2003 & 1\({}^{\circ}\)\(\times\) 1\({}^{\circ}\) & hourly & [PERSON], et al. [69] \\  & LUE & 122–130 Pg C yr\({}^{-1}\) & 2000–2016 & 500 m & 8 day & [PERSON] et al. [70] \\  & LUE & 108–119 Pg C yr\({}^{-1}\) & 2004–2012 & 1 km & 8 day & [PERSON], et al. [71] \\  & ML&8 BESS & 131–163 Pg C yr\({}^{-1}\) & 2005–2015 & 0.5\({}^{\circ}\)\(\times\) 0.5\({}^{\circ}\) & monthly & [PERSON], et al. [72] \\  & GOSIF & 136 \(\pm\) 9 Pg C yr\({}^{-1}\) & 2000–2023 & 0.05\({}^{\circ}\)\(\times\) 0.05\({}^{\circ}\) & 8 day & [PERSON] and [PERSON] [73] \\  & EC-LUE & 106 \(\pm\) 3 Pg C yr\({}^{-1}\) & 1982–2017 & 0.05\({}^{\circ}\)\(\times\) 0.05\({}^{\circ}\) & 5, 6, 8 day & [PERSON], et al. [74] \\  & ML & 117 \(\pm\) 15 Pg C yr\({}^{-1}\) & 1999–2019 & 0.05\({}^{\circ}\)\(\times\) 0.05\({}^{\circ}\) & monthly & [PERSON] et al. [58] \\ \hline \multirow{8}{*}{ET} & RS-PM & 417 \(\pm\) 38 mm yr\({}^{-1}\) & 2000–2003 & 0.5\({}^{\circ}\)\(\times\) 0.6\({}^{\circ}\) & 8 day & [PERSON], et al. [8] \\  & ML & 500 \(\pm\) 23 mm yr\({}^{-1}\) & 1982–2008 & 0.5\({}^{\circ}\)\(\times\) 0.5\({}^{\circ}\) & monthly & [PERSON], et al. [20] \\ \cline{1-1}  & PT & 522 mm yr\({}^{-1}\) & 1980–2016 & 0.25\({}^{\circ}\)\(\times\) 0.25\({}^{\circ}\) & daily & [PERSON], et al. [75] \\ \cline{1-1}  & WB & 558–650 mm yr\({}^{-1}\) & 1982–2009 & 0.5\({}^{\circ}\)\(\times\) 0.5\({}^{\circ}\) & annual & [PERSON], et al. [76] \\ \cline{1-1}  & PML-V1 & 538 \(\pm\) 57 mm yr\({}^{-1}\) & 1998–2012 & 0.5\({}^{\circ}\)\(\times\) 0.5\({}^{\circ}\) & monthly & [PERSON] et al. [77] \\ \hline \end{tabular}  
Notes: the original units of km\({}^{3}\) were converted to mm year\({}^{-1}\) through dividing by the total land area excluding Antarctica and Greenland.  
\end{table} 
Table 4: Summary of global GPP and ET products. forest regions, including tropical rainforest (e.g., Amazon and Central Africa) and temperate forest (e.g., Europe and Eastern US). The low WUE appeared in the dry (e.g., Middle East, Western U.S., and Australia) and/or cold regions (e.g., boreal North America and Eurasia) (Figure 7a). This pattern of WUE was similar to satellite-based observations (Figure 7b), though the ECSIF product estimated lower WUE at the high latitudes (Figure 7c). On the global scale, ECSIF products yielded an area-weighted WUE of 1.8 \(\pm\) 0.207 g C kg\({}^{-1}\) H\({}_{2}\)O yr\({}^{-1}\) (mean \(\pm\) standard deviation) during 2001-2020, close to 1.63 \(\pm\) 0.118 g C kg\({}^{-1}\) H\({}_{2}\)O yr\({}^{-1}\) from ensemble products.