Articles | Volume 18, issue 4
Nonlin. Processes Geophys., 18, 469–475, 2011
https://doi.org/10.5194/npg-18-469-2011
Nonlin. Processes Geophys., 18, 469–475, 2011
https://doi.org/10.5194/npg-18-469-2011

Research article 14 Jul 2011

Research article | 14 Jul 2011

Is the Atlantic Multidecadal Oscillation (AMO) a statistical phantom?

M. Vincze and I. M. Jánosi M. Vincze and I. M. Jánosi
  • Department of Physics of Complex Systems, Eötvös Loránd University, Pázmány P. s. 1/A, 1117 Budapest, Hungary

Abstract. In this work we critically compare the consequences of two assumptions on the physical nature of the AMO index signal. First, we show that the widely used approach based on red noise statistics cannot fully reproduce the empirical correlation properties of the record. Second, we consider a process of long range power-law correlations and demonstrate its better fit to the AMO signal. We show that in the latter case, the multidecadal oscillatory mode of the smoothed AMO index with an assigned period length of 50–70 years can be a simple statistical artifact, a consequence of limited record length. In this respect, a better term to describe the observed fluctuations of a smooth power-law spectrum is Atlantic Multidecadal Variability (AMV).

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