## 3 Results
### Comparison of Regional Scale Modeling Results and Satellite Data  
Hourly modeled _GPP_ at the regional scale also presented clear seasonal changes. Figure 7a-d depict examples of 8-day sums of hourly modeled _GPP_ from winter to autumn. Because little or no valid MODIS _LAI_ was detected in the urban land close to the Tokyo bay in our study area year-round, _GPP_ was zero there. In January, our model estimated up to 10.0 gC m\({}^{-2}\) 8-day\({}^{-1}\) photosynthetic carbon uptake in deciduous forests and urban vegetated land. In contrast, _GPP_ was almost 30.0 gC m\({}^{-2}\) 8-day\({}^{-1}\) in evergreen forests, even in winter. When spring approached and temperatures increased, so did _GPP_ in such evergreen forests. The _GPP_ remained low in deciduous forests and some urban vegetated land, as the leaf area had not fully expanded yet. Summertime _GPP_ was about 40.0-90.0 gC m\({}^{-2}\) 8-day\({}^{-1}\) in ecosystems of all types because of favorable solar radiation and temperature conditions. It then decreased to 10.0-70.0 gC m\({}^{-2}\) 8-day\({}^{-1}\) in autumn until leaf fall occurred. The reason to calculate 8-day _GPP_ of the study area was that few _GPP_ datasets or reference values in earlier studies were available at the sub-daily scale. In fact, only [PERSON] et al. [133] has modeled global half-hourly biogenic CO\({}_{2}\) flux data, but the spatial resolution (0.5\({}^{\circ}\)) of this dataset was too coarse to validate our modeling results. Therefore, comparisons between our 8-day _GPP_ results and MODIS _GPP_[124; 125] or GOSIF _GPP_[126] (Figure 7e-p) were presented. As Figure 7e-h show, our model estimated higher (0.0-30.0 gC m\({}^{-2}\)) 8-day _GPP_ than the MODIS one in evergreen forests in the northeast and west of the study area. In contrast, the modeled 8-day _GPP_ was 0.0-20.0 gC m\({}^{-2}\) lower compared to MODIS 8-day _GPP_ in the western deciduous forests and southeastern evergreen forests; for the latter, the discrepancy was up to 30.0 gC m\({}^{-2}\) in summertime (Figure 7g). Over seasons, the range of difference was larger in summer than in winter while the spatial patterns remained the same, as the average and standard deviation of the difference between the modeled and MODIS 8-day _GPP_ during the period 2010-2018 in Figure 7m-o indicate. In January (Figure 7i) and October (Figure 7l), the difference between the modeled and GOSIF 8-day _GPP_ was similar to the case of the modeled and MODIS 8-day _GPP_ comparisons. Interestingly, GOSIF 8-day _GPP_ was lower (up to 40.0 gC m\({}^{-2}\)) than our modeled results or MODIS _GPP_ in April (Figure 7j), and then became much larger than the latter two estimates in July (Figure 7k). The favorable conditions (e.g., warm temperature and sufficient solar radiation) in spring and frequent rain in summer shaped the seasonal patterns of our modeled _GPP_, which probably led to the discrepancy with GOSIF 8-day _GPP_. The average and standard deviation of the difference between the modeled and GOSIF 8-day _GPP_ during the period 2010-2018 are presented in Figure 7n-p. In addition to forests and partially vegetated urban area, MODIS _GPP_[124; 125] also provides _GPP_ estimates in agricultural land in the northeast of the study area that was not included in our simulations. GOSIF _GPP_[126] estimated a photosynthetic carbon uptake of 0-10.0 gC m\({}^{-2}\) 8-day\({}^{-1}\) in