GRACE-REC: a reconstruction of climate-driven water storage changes over the last century
GRACE-REC: a reconstruction of climate-driven water storage changes over the last century
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DOI：
10.5194/essd-11-1153-2019
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发表时间：
2019-08-02
影响因子：
11.4
通讯作者：
Gudmundsson, Lukas
中科院分区：
文献类型：
--
作者：
Humphrey, Vincent;Gudmundsson, Lukas
大陆上储存的水量是地球系统中水团和能量交换的一个重要制约因素，在地方和大陆尺度上都表现出很大的年际变化。从2002年到2017年，重力恢复与气候实验（GRACE）使命的卫星以前所未有的准确度观察到了陆地水储存（TWS）的变化。在本文中，我们使用GRACE观测数据训练的统计模型，从历史和近实时气象数据集以每日和每月的尺度重建TWS过去的气候驱动变化。与大多数单独表示水库的水文模型不同（例如，雪，土壤水分），通常提供一个单一的模式运行，所提出的方法直接重建总TWS的变化，并包括数百个集合成员，可用于量化预测的不确定性。我们将这些数据驱动的TWS估计与其他独立的评估数据集进行比较，如海平面预算，大气再分析的大规模水平衡和原位径流测量。我们发现，所提出的方法执行整体以及或优于一组国家的最先进的全球水文模型（水资源再分析第2版）。我们提供重建TWS异常在0.5度的空间分辨率，在日常和每月的尺度在1901年至今，基于两个不同的GRACE产品和三个不同的气象强迫数据集，导致6个重建TWS数据集的100个集合成员。可能的用户群体和应用包括水文建模和模型基准、海平面预算研究、干旱频率的长期变化评估、大地测量时间序列中的气候信号分析以及GRACE和GRACE后续飞行任务之间数据差距的解释。所呈现的数据集发布在https://doi.org/10.6084/m9.figshare.7670849（Humphrey和Gudmundsson，2019）上，并将定期发布更新。
The amount of water stored on continents is an important constraint for water mass and energy exchanges in the Earth system and exhibits large inter-annual variability at both local and continental scales. From 2002 to 2017, the satellites of the Gravity Recovery and Climate Experiment (GRACE) mission have observed changes in terrestrial water storage (TWS) with an unprecedented level of accuracy. In this paper, we use a statistical model trained with GRACE observations to reconstruct past climate-driven changes in TWS from historical and near-real-time meteorological datasets at daily and monthly scales. Unlike most hydrological models which represent water reservoirs individually (e.g., snow, soil moisture) and usually provide a single model run, the presented approach directly reconstructs total TWS changes and includes hundreds of ensemble members which can be used to quantify predictive uncertainty. We compare these data-driven TWS estimates with other independent evaluation datasets such as the sea level budget, large-scale water balance from atmospheric reanalysis, and in situ streamflow measurements. We find that the presented approach performs overall as well or better than a set of state-of-the-art global hydrological models (Water Resources Reanalysis version 2). We provide reconstructed TWS anomalies at a spatial resolution of 0.5 degrees, at both daily and monthly scales over the period 1901 to present, based on two different GRACE products and three different meteorological forcing datasets, resulting in six reconstructed TWS datasets of 100 ensemble members each. Possible user groups and applications include hydrological modeling and model benchmarking, sea level budget studies, assessments of long-term changes in the frequency of droughts, the analysis of climate signals in geodetic time series, and the interpretation of the data gap between the GRACE and GRACE Follow-On missions. The presented dataset is published at https://doi.org/10.6084/m9.figshare.7670849 (Humphrey and Gudmundsson, 2019) and updates will be published regularly.