Robust estimation of background noise and signal detection in climatic time series
Robust estimation of background noise and signal detection in climatic time series
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DOI：
10.1007/bf00142586
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发表时间：
1996-07-01
期刊：
影响因子：
4.8
通讯作者：
Lees, JM
中科院分区：
文献类型：
--
作者：
Mann, ME;Lees, JM
我们提出了一种新的技术，用于隔离气候信号的时间序列与特征的“红”噪声背景，产生时间持久性。这种背景估计的“鲁棒”的程序，与传统的技术不同，很大程度上是无偏的存在下，沉浸在噪声中的信号。利用多锥度频谱分析方法，该技术进一步提供了纯谐波（周期性）信号和宽带（“准周期性”）信号之间的区别。我们的信号检测过程的有效性证明了与合成的例子，模拟各种可能的周期性和准周期性信号沉浸在红噪声。我们将我们的方法应用于历史气候和古气候时间序列的例子。对大约300万年的沉积物岩芯的分析表明，在已知的天文强迫周期和一个重要的准周期100年的峰值上有显著的周期成分。大约1500年的树轮重建斯堪的纳维亚夏季温度的分析表明，近世纪的时间尺度上，一个年代际16-18年的时间尺度，在年际厄尔尼诺/南方涛动（ENSO）带，并在quasibiennial的时间尺度上显着的准周期信号。分析大盐湖144年的月体积变化记录，揭示了一个显着的宽带显着的年代际变化，ENSO时间尺度的峰值，年周期及其谐波。详细关注历史估计的全球平均地表温度记录，我们发现一个非常显着的长期趋势相对于估计的红噪声背景，弱显着的准周期信号内的ENSO波段。十年和准两年的信号在这个系列中是微不足道的。
We present a new technique for isolating climate signals in time series with a characteristic 'red' noise background which arises from temporal persistence. This background is estimated by a 'robust' procedure that, unlike conventional techniques, is largely unbiased by the presence of signals immersed in the noise. Making use of multiple-taper spectral analysis methods, the technique further provides for a distinction between purely harmonic (periodic) signals, and broader-band ('quasiperiodic') signals. The effectiveness of our signal detection procedure is demonstrated with synthetic examples that simulate a variety of possible periodic and quasiperiodic signals immersed in red noise. We apply our methodology to historical climate and paleoclimate time series examples. Analysis of a approximate to 3 million year sediment core reveals significant periodic components at known astronomical forcing periodicities and a significant quasiperiodic 100 year peak. Analysis of a roughly 1500 year tree-ring reconstruction of Scandinavian summer temperatures suggests significant quasiperiodic signals on a near-century timescale, an interdecadal 16-18 year timescale, within the interannual El Ninio/Southem Oscillation (ENSO) band, and on a quasibiennial timescale. Analysis of the 144 year record of Great Salt Lake monthly volume change reveals a significant broad band of significant interdecadal variability, ENSO-timescale peaks, an annual cycle and its harmonics. Focusing in detail on the historical estimated global-average surface temperature record, we find a highly significant secular trend relative to the estimated red noise background, and weakly significant quasiperiodic signals within the ENSO band. Decadal and quasibiennial signals are marginally significant in this series.