The preliminary research about the precursory signals of abrupt climate change based on critical slowing down phenomenon

Abstract

In recent years, critical slowing down phenomenon has shown great potentials in the area of disclosing whether complex dynamic system tends to critical cataclysm. Based on the concepts of critical slowing down, the observed data of pacific decadal oscillation (PDO) index and the national average monthly temperature are processed in this article to study the precursory signals of abrupt climate change. Take the abrupt climate change in a period from the late1970s to the early 1980s for example, the variances and autocorrelation coefficients which can characterize critical slowing down are calculated separately. The results show that the PDO index and the national average monthly temperature both have obviously a critical slowing down phenomenon before the abrupt climate change takes place, which indicates that critical slowing down phenomenon is a possible early warning signal for abrupt climate change. The introduction of critical slowing down theory into abrupt climate change precursory signals and study on it have practical significance and important scientific value for thoroughly understanding the abrupt climate change and for catching the precursory signals of abrupt climate change.

A study of the early warning signals of abrupt change in the Pacific decadal oscillation

“…It is also more convenient to find the early warning signal of the abrupt climate change. References [25], [26], and [42] contain a detailed description regarding the influences of the window size and moving step on the stability results and the relevant research on the identification of the spurious signal. For example, when the data volume is fixed, the larger window size and longer moving step give a stabler result.…”

Early warning signals of abrupt temperature change in different regions of China over the past 50 years

“…According to our study, a reasonable selection window and lag time can improve the quality of the detection result. [19,20] The aforementioned theoretical analysis shows that the critical slowing down leads to a reduction in the internal rate of change in the system, and at any moment causes the state of the system to increasingly resemble its previous state, so the autocorrelation coefficient approaches 1. The increase in the autocorrelation coefficient when the climate systems approach the critical point, which is one kind of critical slowing down phenomenon, indicates that the climate system may soon change abruptly.…”

“…The theory has important practical and scientific meaning, not only for a deeper understanding of earthquakes in their active stage, but also for improving the levels of earthquake predictions. Wu, Yan et al [19][20][21] used the theory to study the early warning signals of abrupt climate change, and discussed the possibility of using the critical slowing down phenomenom. In addition, the applicability of different data methods was investigated, and the conclusion was that different window scales and lag step lengths can affect the stabilities of the calculation results.…”