Vishwakarma Bramha Dutt, Zhang Jinwei, Sneeuw Nico
School of Geographical Sciences, University of Bristol, University Road, BS8 1SS, Bristol, UK.
Institute of Geodesy, University of Stuttgart, Geschwister-Scholl Strasse 24D, Stuttgart, Germany.
Sci Data. 2021 Mar 26;8(1):95. doi: 10.1038/s41597-021-00862-6.
The Gravity Recovery And Climate Experiment (GRACE) satellite mission recorded temporal variations in the Earth's gravity field, which are then converted to Total Water Storage Change (TWSC) fields representing an anomaly in the water mass stored in all three physical states, on and below the surface of the Earth. GRACE provided a first global observational record of water mass redistribution at spatial scales greater than 63000 km. This limits their usability in regional hydrological applications. In this study, we implement a statistical downscaling approach that assimilates 0.5° × 0.5° water storage fields from the WaterGAP hydrology model (WGHM), precipitation fields from 3 models, evapotranspiration and runoff from 2 models, with GRACE data to obtain TWSC at a 0.5° × 0.5° grid. The downscaled product exploits dominant common statistical modes between all the hydrological datasets to improve the spatial resolution of GRACE. We also provide open access to scripts that researchers can use to produce downscaled TWSC fields with input observations and models of their own choice.
重力恢复与气候实验（GRACE）卫星任务记录了地球重力场的时间变化，这些变化随后被转换为总蓄水量变化（TWSC）场，代表地球表面及以下所有三种物理状态下储存的水体质量异常。GRACE提供了首个空间尺度大于63000千米的全球水体质量再分布观测记录。这限制了其在区域水文应用中的可用性。在本研究中，我们实施了一种统计降尺度方法，该方法将来自WaterGAP水文模型（WGHM）的0.5°×0.5°蓄水量场、3个模型的降水场、2个模型的蒸散量和径流量与GRACE数据进行同化，以获得0.5°×0.5°网格上的TWSC。降尺度产品利用了所有水文数据集之间占主导地位的共同统计模式，以提高GRACE的空间分辨率。我们还提供了开放获取的脚本，研究人员可以使用这些脚本，根据自己选择的输入观测数据和模型生成降尺度的TWSC场。
