## 3 Results
### GPP Validation
#### 3.1.1 Eight-Day GPP
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Biome Type**} & \multirow{2}{*}{**Comparison**} & \multirow{2}{*}{**R\({}^{2}\)**} & \multicolumn{2}{c}{**Mean (SD)**} & \multirow{2}{*}{**Bias**} & \multirow{2}{*}{**RMSE (\%)**} & \multirow{2}{*}{**n**} \\  & & & & **(gC\(\cdot\)m\({}^{-2}\).8-d\({}^{-1}\))** & & & \\ \hline \multirow{4}{*}{ENF} & MOD\_GMAO vs. Flux\_Tower & 0.71 ** & 19 (20) vs. 30 (27) & \(-11\) & \(\Sigma\)2 & \multirow{4}{*}{920} \\  & MOD\_Tower\_Tower & Flux\_Tower & 0.72 ** & 19 (19) vs. 30 (27) & \(-11\) & \(\Sigma\)2 & \multirow{4}{*}{920} \\  & GMAO\_GLASS vs. Flux\_Tower & 0.75 ** & 21 (22) vs. 30 (27) & \(-9\) & \(47\) & \\  & Tower\_GLASS vs. Flux\_Tower & 0.76 ** & 20 (21) vs. 30 (27) & \(-10\) & \(47\) & \\ \hline \multirow{4}{*}{EBF} & MOD\_GMAO vs. Flux\_Tower & 0.14 ** & 29 (0) vs. 40 (24) & \(-11\) & \(54\) & \multirow{4}{*}{1058} \\  & MOD\_Tower\_Tower & Flux\_Tower & 0.21 ** & 26 (17) vs. 40 (24) & \(-14\) & \(51\) & \\  & GMAO\_GLASS vs. Flux\_Tower & 0.52 ** & 35 (24) vs. 40 (24) & \(-5\) & \(39\) & \\  & Tower\_GLASS vs. Flux\_Tower & 0.73 ** & 31 (19) vs. 40 (24) & \(-9\) & \(33\) & \\ \hline \multirow{4}{*}{DBF} & MOD\_GMAO vs. Flux\_Tower & 0.75 ** & 23 (25) vs. 39 (42) & \(-16\) & \(63\) & \multirow{4}{*}{1104} \\  & MOD\_Tower\_Tower & Flux\_Tower & 0.77 ** & 19 (20) vs. 39 (42) & \(-20\) & \(68\) & \\  & GMAO\_GLASS vs. Flux\_Tower & 0.86 ** & 27 (28) vs. 39 (42) & \(-12\) & \(49\) & \\  & Tower\_GLASS vs. Flux\_Tower & 0.89 ** & 23 (23) vs. 39 (42) & \(-16\) & \(55\) & \\ \hline \multirow{4}{*}{MF} & MOD\_GMAO vs. Flux\_Tower & 0.73 ** & 22 (24) vs. 33 (30) & \(-11\) & \(53\) & \multirow{4}{*}{1196} \\  & MOD\_Tower\_Tower & Flux\_Tower & 0.73 ** & 17 (18) vs. 33 (30) & \(-16\) & \(65\) & \\  & GMAO\_GLASS vs. Flux\_Tower & 0.81 ** & 24 (25) vs. 33 (30) & \(-9\) & \(45\) & \\  & Tower\_GLASS vs. Flux\_Tower & 0.81 ** & 18 (18) vs. 33 (30) & \(-15\) & \(59\) & \\ \hline \multirow{4}{*}{GRA} & MOD\_GMAO vs. Flux\_Tower & 1.41 ** & 14 (14) vs. 19 (24) & \(-5\) & \(98\) & \multirow{4}{*}{1058} \\  & MOD\_Tower\_Tower & Flux\_Tower & 0.43 ** & 14 (12) vs. 19 (24) & \(-5\) & \(98\) & \\  & GMAO\_GLASS vs. Flux\_Tower & 0.56 ** & 15 (17) vs. 19 (24) & \(-4\) & \(83\) & \\  & Tower\_GLASS vs. Flux\_Tower & 0.64 ** & 14 (15) vs. 19 (24) & \(-5\) & \(80\) & \\ \hline \multirow{4}{*}{CRO} & MOD\_GMAO vs. Flux\_Tower & 0.34 ** & 20 (20) vs. 30 (40) & \(-10\) & \(94\) & \multirow{4}{*}{1150} \\  & MOD\_Tower vs. Flux\_Tower & 0.32 ** & 18 (19) vs. 30 (40) & \(-12\) & \(98\) & \\ \cline{1-1}  & GMAO\_GLASS vs. Flux\_Tower & 0.35 ** & 25 (23) vs. 30 (40) & \(-5\) & \(89\) & \\ \cline{1-1}  & Tower\_GLASS vs. Flux\_Tower & 0.34 ** & 22 (21) vs. 30 (40) & \(-8\) & \(92\) & \\ \hline \multirow{4}{*}{All} & MOD\_GMAO vs. Flux\_Tower & 0.52 ** & 21 (21) vs. 32 (33) & \(-11\) & \(24\) & \multirow{4}{*}{6486} \\  & MOD\_Tower vs. Flux\_Tower & 0.52 ** & 19 (18) vs. 32 (33) & \(-13\) & \(24\) & \\ \cline{1-1}  & GMAO\_GLASS vs. Flux\_Tower & 0.63 ** & 24 (24) vs. 32 (33) & \(-8\) & \(23\) & \\ \cline{1-1}  & Tower\_GLASS vs. Flux\_Tower & 0.65 ** & 21 (20) vs. 32 (33) & \(-11\) & \(23\) & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Biome-based comparison of eight-day GPP derived from the site estimates with those derived from the MODIS algorithms (MOD_GMAO GPP, MOD_Tower GPP, GMAO_GLASS GPP and Tower_GLASS GPP). ENF: evergreen needleaf forests; EBF: evergreen broadleaf forests; DBF: deciduous broadleaf forests; MF: mixed forests; GRA: grasslands; CRO: croplands. algorithms were superior to the MOD_GMAO GPP and MOD_Tower GPP algorithms across all six biome types.