Independent patterns of water mass anomalies over Australia from satellite data and models
Independent patterns of water mass anomalies over Australia from satellite data and models
复制标题
DOI：
10.1016/j.rse.2012.05.023
复制
发表时间：
2012-09
影响因子：
13.5
通讯作者：
E. Forootan;J. Awange;J. Kusche;B. Heck;A. Eicker
中科院分区：
文献类型：
--
作者：
E. Forootan;J. Awange;J. Kusche;B. Heck;A. Eicker
重力恢复和气候实验（GRACE）产品可以量化全球到区域尺度的总水储存（TWS）变化。然而，GRACE测量的量代表垂直柱上积分的质量信号，需要将它们分离到原始源中。这种分离对澳大利亚至关重要，因为GRACE的估计受到周围海洋泄漏的影响。独立成分分析（伊卡）方法，使用高阶统计量，在这里实现分离GRACE派生的水存储信号在澳大利亚大陆从其周围的海洋，从2002年10月到2011年5月。伊卡应用于GRACE的性能进行了比较，伊卡的WaterGAP全球水文模型（WGHM）和ICA的澳大利亚水资源评估（AWRA）系统。为了研究降雨变率对导出的独立模式的影响，使用热带降雨测量使命（TRMM）数据集，从2000年1月至2011年5月。在GRACE-TWS上实施伊卡在将大陆水文信号与周围海洋异常分离方面显示出显着的改进，这是使用传统的主成分分析无法实现的。仅用GRACE中位于大陆上空的独立分量重建的大陆TWS变化与WGHM TWS和AWRA TWS有很高的相关性。海洋上的质量浓度，特别是S2半日混叠模式被分离为独立的模式。GRACE独立分量与气候遥相关的相关分析表明，北方大洋、卡奔塔利亚湾和澳大利亚东北部地区的质量异常与厄尔尼诺-南方涛动显著相关，而澳大利亚南部和东南部地区的质量异常主要与印度洋偶极子相关。
The Gravity Recovery and Climate Experiment (GRACE) products allow the quantification of total water storage (TWS) changes at global to regional scales. However, the quantity measured by GRACE represents mass signals integrated over vertical columns, requiring their separation into their original sources. Such a separation is vital for Australia, for which GRACE estimates are affected by leakage from the surrounding oceans. The independent component analysis (ICA) method that uses higher-order statistics, is implemented here to separate GRACE-derived water storage signals over the Australian continent from its surrounding oceans, covering from October 2002 to May 2011. The performance of ICA applied to GRACE is then compared to the ICA of WaterGAP Global Hydrology Model (WGHM) and the ICA of the Australian Water Resources Assessment (AWRA) system. To study the influence of rainfall variability on the derived independent patterns, use is made of Tropical Rainfall Measuring Mission (TRMM) data set, from January 2000 to May 2011. Implementing ICA on GRACE-TWS showed a remarkable improvement in separating the continental hydrological signals from the surrounding oceanic anomalies, which was not achievable using a conventional principle component analysis. Reconstructing the continental TWS changes using only those independent components of GRACE that were located over the continent showed a high correlation with WGHM-TWS and AWRA-TWS. Mass concentrations over the oceans and particularly S2 semi-diurnal aliased pattern were separated as independent modes. Correlation analysis between the independent components of GRACE and climate teleconnections showed that the mass anomalies over the northern ocean, Gulf of Carpentaria and north-eastern parts of Australia were significantly correlated with the El Niño-Southern Oscillation, while those over south and south-eastern parts of Australia were mainly linked to the Indian Ocean Dipole.