试用临界慢化原理探讨气候突变

Using the principle of critical slowing down to discuss the abrupt climate change

近年来,临界慢化现象在揭示复杂动力系统是否趋向于临界性灾变方面展示了重要潜力.本文基于临界慢化的理念,着重研究不同噪声影响下,气候突变前兆信号出现的时间;对含有不同噪声的气温观测资料、太平洋年代际振荡指数以及阿留申低压强度资料进行处理,研究突变的前兆信号.以20世纪70年代末80年代初这次气候突变为例,分别计算了表征临界慢化现象的方差和自相关系数.结果表明,临界慢化现象出现在具有不同信噪比的资料中,这表明临界慢化现象可能是气候突变发生前的一个前兆信号,并且噪声对气候突变前兆信号的检测结果影响较小,从而论证了临界慢化现象检测突变前兆信号的可靠性,为该方法在实际观测资料中的广泛应用提供了实验基础.

In recent years, critical slowing down phenomenon has shown great potentials in disclosing whether a complex dynamic tends to critical cataclysm. Based on the concepts of critical slowing down, the observed data of temperature and the pacific decadal oscillation （PDO） index and the intensity of Aleutian low pressure, which have different noises are processed in this article to study the precursory signals of abrupt climate change. Take the abrupt climate change in the late1970s–early 1980s as an example, then variances and autocorrelation coefficients which can characterize critical slowing down will be calculated separately; the occurring time of precursory signal of abrupt climate change under the noises influence is studied. The results show that the critical slowing down phenomenon appears in the data with different signal-to-noise ratios before the abrupt climate change takes place, which indicates that critical slowing down phenomenon is a possible early warning signal for abrupt climate change and the noise has less influence on the test results for precursory signals of abrupt climate change. Accordingly, it demonstrates the reliability of critical slowing down phenomenon to test the precursory signals of abrupt climate change, which provides an experimental basis for the wide applications of the present method in real observation data.