Assessing the Significance of Changes in ENSO Amplitude Using Variance Metrics
Assessing the Significance of Changes in ENSO Amplitude Using Variance Metrics
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DOI：
10.1175/jcli-d-13-00077.1
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发表时间：
2014-06
影响因子：
4.9
通讯作者：
T. Russon;A. Tudhope;G. Hegerl;A. Schurer;M. Collins
中科院分区：
文献类型：
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作者：
T. Russon;A. Tudhope;G. Hegerl;A. Schurer;M. Collins
与ENSO有关的时间序列记录的方差，如赤道太平洋SST指数的年际异常或带通滤波分量，提供了一种量化ENSO振幅变化的方法。然而，以这种方式定义的幅度变化的重要性的鲁棒评估，阻碍了非强迫气候系统内的这种方差度量的抽样分布的不确定性。本研究表明，这些抽样分布的非强迫CGCM模拟范围内提供的经验约束与预期的参数形式是一致的，这表明标准的参数测试策略可以稳健地应用，即使在非线性ENSO系统的情况下。根据这种方法，方差的非强迫相对变化的抽样分布可能受到单一参数τd的约束：其值取决于用来提取时间序列变异性中与厄尔尼诺/南方涛动有关的部分的方法的选择。在...
AbstractThe variance of time series records relating to ENSO, such as the interannual anomalies or bandpass filtered components of equatorial Pacific SST indices, provides one approach to quantifying changes in ENSO amplitude. Robust assessment of the significance of changes in amplitude defined in this way is, however, hampered by uncertainty regarding the sampling distributions of such variance metrics within an unforced climate system. The present study shows that the empirical constraints on these sampling distributions provided by a range of unforced CGCM simulations are consistent with the expected parametric form, suggesting that standard parametric testing strategies can be robustly applied, even in the case of the nonlinear ENSO system. Under such an approach, the sampling distribution of unforced relative changes in variance may be constrained by a single parameter τd: the value of which depends on the choice of method used to extract the ENSO-related component of time series variability. In the...