Chaotic Properties of the Arctic Oscillation Index

Abstract

In this letter, we investigate nonlinear properties of the underlying dynamics for the Arctic Oscillation Index (AOI). First, we develop a test statistic for surrogate data analysis so that we can deal with the high-dimensionality of AOI. Second, we validate the test statistic with toy models. Then, by applying the proposed new test statistic with surrogate data to the dataset of AOI for the last 60 years, we show that AOI is nonlinear with determinism beyond pseudo-periodicity. These results mean that the underlying dynamics of AOI is consistent with deterministic chaos, implying that it is predictable in a short-term but not in a long-term.