## 5 Conclusions
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Flux Towers** & **GOME-2 SIF** & **GOSIF** & **EVI2** & **Latitude** & **Longitude** \\ \hline CA-Gro & 0 & 26 & 19 & 48.22 & \(-\)82.16 \\ CA-Man & 15 & 14 & 12 & 55.88 & \(-\)98.48 \\ CA-Oas & 5 & 2 & 1 & 53.63 & \(-\)106.20 \\ CA-Obs & 32 & 14 & 11 & 53.99 & \(-\)105.12 \\ CA-Qfo & 11 & 4 & 13 & 49.69 & \(-\)74.34 \\ FI-Hyry & 16 & 23 & 25 & 61.85 & 24.29 \\ FI-Let & 28 & 46 & 35 & 60.64 & 23.96 \\ FI-Com & 32 & 6 & 4 & 68.00 & 24.21 \\ FI-Sod & 7 & 16 & 22 & 67.36 & 26.64 \\ RU-SdP & 5 & 7 & 4 & 62.26 & 129.17 \\ \hline \hline \multicolumn{2}{c}{Ave Difference} & 15.0 & 15.6 & 14.7 & \\ \hline \end{tabular}
\end{table} 
Table 4: Differences between SOSs derived from satellite dataset and each flux tower site. The SOSs estimated from GOME-2 SIF, GOSIF, and EVI2 at their optimal spatial resolution in detecting phenology, i.e., 3.5\({}^{\circ}\), 0.05\({}^{\circ}\), and 0.005\({}^{\circ}\). \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Poor** & **GOME-2 SIF** & **GOSIF** & **EVI2** & **FLUX-GPP** \\ \hline TMAX-1 & \(0.099\) & \(-0.694\) & \(-0.233\) & \(-0.120\) \\ TMN-1 & \(-0.112\) & \(0.478\) & \(0.006\) & \(0.033\) \\ P-1 & \(0.746\) & \(-0.066\) & \(0.632\) & \(0.542\) \\ R-1 & \(0.439\) & \(0.559\) & \(0.851\) & \(0.583\) \\ TMAX-2 & \(-0.146\) & \(-0.634\) & \(-0.392\) & \(0.074\) \\ TMN-2 & \(0.103\) & \(0.617\) & \(0.414\) & \(-0.184\) \\ P-2 & \(0.536\) & \(0.265\) & \(0.483\) & \(0.456\) \\ R-2 & \(0.321\) & \(0.620\) & \(0.798\) & \(0.578\) \\ TMAX-3 & \(-0.142\) & \(-0.644\) & \(-0.456\) & \(0.276\) \\ TMN-3 & \(0.050\) & \(0.626\) & \(0.509\) & \(-0.346\) \\ P-3 & \(0.372\) & \(0.125\) & \(0.523\) & \(0.543\) \\ R-3 & \(0.075\) & \(0.489\) & \(0.798\) & \(0.685\) \\ \hline \hline \end{tabular}
\end{table} 
Table 7: The relationships between spring phenology and climate factors based on satellite datasets and flux tower sites (Eurasia). \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Poor** & **GOME-2 SIF** & **GOSIF** & **EVI2** & **FLUX-GPP** \\ \hline TMAX-1 & \(0.143\) & \(0.133\) & \(-0.322\) & \(-0.045\) \\ TMN-1 & \(0.209\) & \(-0.070\) & \(-0.039\) & \(0.082\) \\ P-1 & \(0.003\) & \(-0.065\) & \(-0.075\) & \(0.149\) \\ R-1 & \(0.249\) & \(0.077\) & \(0.467\) & \(0.452\) \\ TMAX-2 & \(0.114\) & \(0.087\) & \(-0.354\) & \(0.087\) \\ TMMN-2 & \(-0.172\) & \(-0.046\) & \(0.137\) & \(-0.058\) \\ P-2 & \(0.020\) & \(-0.115\) & \(-0.084\) & \(0.000\) \\ R-2 & \(0.415\) & \(0.114\) & \(0.322\) & \(0.434\) \\ TMAX-3 & \(0.048\) & \(0.135\) & \(-0.470\) & \(0.187\) \\ TMN-3 & \(-0.116\) & \(-0.102\) & \(0.298\) & \(-0.166\) \\ P-3 & \(-0.051\) & \(-0.165\) & \(0.003\) & \(-0.075\) \\ R-3 & \(0.113\) & \(0.035\) & \(0.295\) & \(0.382\) \\ \hline \hline \end{tabular}
\end{table} 
Table 8: The relationships between spring phenology and climate factors based on satellite datasets and PEF725 phenological observation sites. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Poor** & **GOME-2 SIF** & **GOSIF** & **EVI2** & **FLUX-GPP** \\ \hline TMAX-1 & \(0.143\) & \(0.133\) & \(-0.322\) & \(-0.045\) \\ TMN-1 & \(-0.209\) & \(-0.070\) & \(-0.039\) & \(0.082\) \\ P-1 & \(-0.003\) & \(-0.065\) & \(-0.075\) & \(0.149\) \\ R-1 & \(0.249\) & \(0.077\) & \(0.467\) & \(0.452\) \\ TMAX-2 & \(0.114\) & \(0.087\) & \(-0.354\) & \(0.087\) \\ TMN-2 & \(-0.172\) & \(-0.046\) & \(0.137\) & \(-0.058\) \\ P-2 & \(-0.020\) & \(-0.115\) & \(-0.084\) & \(0.000\) \\ R-2 & \(0.415\) & \(0.114\) & \(0.322\) & \(0.434\) \\ TMAX-3 & \(0.048\) & \(0.135\) & \(-0.470\) & \(0.187\) \\ TMN-3 & \(-0.116\) & \(-0.102\) & \(0.298\) & \(-0.166\) \\ P-3 & \(-0.051\) & \(-0.165\) & \(0.003\) & \(-0.075\) \\ R-3 & \(0.113\) & \(0.035\) & \(0.295\) & \(0.382\) \\ \hline \hline \end{tabular}
\end{table} 
Table 5: The relationships between spring phenology and climate factors based on satellite datasets and flux tower sites (All sites).