Clear-sky Land Surface Upward Longwave Radiation Dataset based on ABI/GOES-16

Surface upward longwave radiation (SULR) is one of the four components of the surface radiation budget, which is the surface outgoing thermal radiation in the spectral domain of 4-100 μm. SULR is an indicator of surface thermal conditions and has a great impact on weather, climate, and phenology. The big earth data derived from satellite remote sensing has been an important tool for the studying of earth science. The Advanced Baseline Imager (ABI) onboard the Geostationary Operational Environmental Satellites (GOES-16) has greatly improved temporal and spectral resolutions compared to the imager sensor of the previous GOES series, and is a good data source for the generation of high spatiotemporal resolution SULR. In this study, based on the single-angle hybrid SULR estimation method and an upper hemisphere correction method of the geostationary satellite, we developed a clear-sky land SULR product for GOES-16 with a half-hourly resolution for the period from 1st January 2018 to 30th June 2020. The dataset was validated using in situ measurements from 65 sites from the Ameriflux radiation network. Compared with the Global Land Surface Satellite (GLASS) SULR product that is generated from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the polar-orbiting Terra and Aqua satellites, the ABI/GOES-16 SULR product has slightly higher accuracy (RMSE (MBE) of 15.9 (-4.4) W/m2 compared with 18.15 (-4.33) W/m2), a spatial resolution of 2 km at nadir (compared with 1 km resolution), and a greatly improved temporal resolution (48 observations compared with 4 times a day).

地表向上长波辐射（SULR）是地表辐射收支的四个组成部分之一，该辐射收支指地表在4-100 μm光谱域内的出射热辐射。SULR是地表热状况的指示器，对天气、气候和物候有着重要的影响。源自卫星遥感的大地球数据已成为地球科学研究的重要工具。相较于前一代GOES系列传感器的成像传感器，搭载于地球同步轨道环境卫星（GOES-16）的先进基线成像仪（ABI）在时间分辨率和光谱分辨率方面均有显著提升，成为生成高时空分辨率SULR的理想数据源。在本研究中，基于单角混合SULR估算方法和地球同步卫星的上半球校正方法，我们为GOES-16开发了具有半小时分辨率的晴空陆地SULR产品，时间跨度为2018年1月1日至2020年6月30日。该数据集通过来自 Ameriflux 辐射网络65个站点的原位测量进行了验证。与源自极地轨道Terra和Aqua卫星搭载的中分辨率成像光谱仪（MODIS）生成的全球陆地表面卫星（GLASS）SULR产品相比，ABI/GOES-16 SULR产品的精度略有提高（均方根误差（平均偏差）为15.9（-4.4）W/m2，相比之下为18.15（-4.33）W/m2），在视场中心处具有2公里的空间分辨率（相比之下为1公里分辨率），并且时间分辨率得到显著改善（48次观测，相比之下为每天4次）。