Abstract. Surface downward shortwave radiation (DSR) and photosynthetically active radiation (PAR) play critical roles in the Earth’s surface processes. As the main inputs of various ecological, hydrological, carbon, and solar photovoltaic models, increasing requirements for high spatiotemporal resolution DSR and PAR estimation with high accuracy have been observed in recent years. However, few existing products satisfy all of these requirements. This study employed a well-established physical-based look-up table (LUT) approach to the GeoNEX gridded top-of-atmosphere bidirectional reflectance factor data acquired by the Advanced Himawari Imager (AHI) and Advanced Baseline Imager (ABI) sensors. It produced a data product of DSR and PAR over both AHI and ABI coverage at an hourly temporal step with a 1 km spatial resolution. GeoNEX DSR data were validated over 63 stations, and GeoNEX PAR data were validated over 27 stations. The validation showed that the new GeoNEX DSR and PAR products have accuracy higher than other existing products, with root mean square error (RMSE) of hourly GeoNEX DSR achieving 74.3 W / m² (18.0 %), daily DSR estimation achieving 18.0 W / m² (9.2 %), hourly GeoNEX PAR achieving 34.9 W / m² (19.6 %), and daily PAR achieving 9.5 W / m² (10.5 %). The study also demonstrated the application of the high spatiotemporal resolution GeoNEX DSR product in investigating the spatial heterogeneity and temporal variability of surface solar radiation. The data product can be accessed through NASA Advanced Supercomputing Division GeoNEX data portal https://data.nas.nasa.gov/geonex/geonexdata/GOES16/GEONEX-L2/DSR-PAR/ and https://data.nas.nasa.gov/geonex/geonexdata/HIMAWARI8/GEONEX-L2/DSR-PAR/ (https://doi.org/10.5281/zenodo.7023863, Wang & Li, 2022).

中文翻译：

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基于GeoNEX的地表向下短波辐射和光合有效辐射的高时空分辨率产品

摘要。地表向下短波辐射 (DSR) 和光合有效辐射 (PAR) 在地球表面过程中发挥着关键作用。作为各种生态、水文、碳和太阳能光伏模型的主要输入，近年来人们对高时空分辨率 DSR 和高精度 PAR 估计的要求越来越高。然而，很少有现有产品能够满足所有这些要求。本研究采用成熟的基于物理的查找表 (LUT) 方法来处理由高级向日葵成像仪 (AHI) 和高级基线成像仪 (ABI) 传感器获取的 GeoNEX 网格化顶部双向反射系数数据。它在 AHI 和 ABI 覆盖范围内以每小时时间步长生成 DSR 和 PAR 数据产品，空间分辨率为 1 公里。GeoNEX DSR 数据在 63 个站点上得到验证，GeoNEX PAR 数据在 27 个站点上得到验证。验证表明，新的GeoNEX DSR和PAR产品的精度高于其他现有产品，每小时GeoNEX DSR的均方根误差（RMSE）达到74.3W / m ² (18.0 %)，每日 DSR 估计达到 18.0 W / m ² (9.2 %)，每小时 GeoNEX PAR 达到 34.9 W / m ² (19.6 %)，每日 PAR 达到 9.5 W / m ²(10.5%)。该研究还展示了高时空分辨率 GeoNEX DSR 产品在研究表面太阳辐射的空间异质性和时间变异性中的应用。数据产品可通过 NASA 高级超级计算部门 GeoNEX 数据门户 https://data.nas.nasa.gov/geonex/geonexdata/GOES16/GEONEX-L2/DSR-PAR/ 和 https://data.nas.nasa 访问.gov/geonex/geonexdata/HIMAWARI8/GEONEX-L2/DSR-PAR/ (https://doi.org/10.5281/zenodo.7023863, Wang & Li, 2022)。