Comparison of NLDAS-2 Simulated and NASMD Observed Daily Soil Moisture. Part I: Comparison and Analysis
Comparison of NLDAS-2 Simulated and NASMD Observed Daily Soil Moisture. Part I: Comparison and Analysis
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DOI：
10.1175/jhm-d-14-0096.1
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发表时间：
2015-10-01
影响因子：
3.8
通讯作者：
Quiring, Steven M.
中科院分区：
文献类型：
--
作者：
Xia, Youlong;Ek, Michael B.;Quiring, Steven M.
本研究利用7个不同生物群系和气候条件下的7个观测网络的土壤湿度数据，对多模式模拟的土壤湿度产品进行了评价。Noah、Mosaic、萨克拉门托土壤水分核算（SAC）和变入渗能力模型（VIC）这四个陆面模型在北美土地数据同化系统（NLDAS-2）的第2阶段运行。度空间分辨率和小时时间分辨率。阿拉巴马州、科罗拉多州、密歇根州、内布拉斯加州、俄克拉何马州、西德克萨斯州和犹他州的数百个地点被用来评估0-10厘米、10-40厘米和40-100厘米土层的模拟土壤湿度。在每个状态下对土壤湿度进行空间平均，以降低噪声。总的来说，除了西德克萨斯州10-40-cm土层和阿拉巴马州40-100-cm土层的异常相关性较弱外，这四个模型捕获了七个州所有三个土层的土壤湿度变化的广泛特征（例如季节变化）。总体而言，Mosaic、SAC和ensemble平均值的模拟能力最高，VIC平均值的模拟能力最低。结果表明，Noah和VIC比观测值湿润，而Mosaic和SAC比观测值干燥，这很可能是由于模式蒸散发的系统误差。
Soil moisture observations from seven observational networks (spanning portions of seven states) with different biome and climate conditions were used in this study to evaluate multimodel simulated soil moisture products. The four land surface models, including Noah, Mosaic, Sacramento soil moisture accounting (SAC), and the Variable Infiltration Capacity model (VIC), were run within phase 2 of the North American Land Data Assimilation System (NLDAS-2), with a ?degrees spatial resolution and hourly temporal resolution. Hundreds of sites in Alabama, Colorado, Michigan, Nebraska, Oklahoma, West Texas, and Utah were used to evaluate simulated soil moisture in the 0-10-, 10-40-, and 40-100-cm soil layers. Soil moisture was spatially averaged in each state to reduce noise. In general, the four models captured broad features (e.g., seasonal variation) of soil moisture variations in all three soil layers in seven states, except for the 10-40-cm soil layer in West Texas and the 40-100-cm soil layer in Alabama, where the anomaly correlations are weak. Overall, Mosaic, SAC, and the ensemble mean have the highest simulation skill and VIC has the lowest simulation skill. The results show that Noah and VIC are wetter than the observations while Mosaic and SAC are drier than the observations, mostly likely because of systematic errors in model evapotranspiration.