中国物理B ›› 2015, Vol. 24 ›› Issue (8): 89201-089201.doi: 10.1088/1674-1056/24/8/089201

• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇    

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

吴浩a b, 侯威b, 颜鹏程b c, 张志森b c, 王阔d   

  1. a Hunan Climate Center, Changsha 410118, China;
    b National Climate Center, Beijing 100081, China;
    c College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China;
    d Zhejiang Climate Center, Hangzhou 310002, China
  • 收稿日期:2015-01-13 修回日期:2015-03-25 出版日期:2015-08-05 发布日期:2015-08-05
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 41175067 and 41305056), the National Basic Research Program of China (Grant No. 2012CB955901), the Special Scientific Research Project for Public Interest of China (Grant No. GYHY201506001), and the Special Fund for Climate Change of China Meteorological Administration (Grant No. CCSF201525).

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

Wu Hao (吴浩)a b, Hou Wei (侯威)b, Yan Peng-Cheng (颜鹏程)b c, Zhang Zhi-Sen (张志森)b c, Wang Kuo (王阔)d   

  1. a Hunan Climate Center, Changsha 410118, China;
    b National Climate Center, Beijing 100081, China;
    c College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China;
    d Zhejiang Climate Center, Hangzhou 310002, China
  • Received:2015-01-13 Revised:2015-03-25 Online:2015-08-05 Published:2015-08-05
  • Contact: Wu Hao E-mail:wuhaophy@163.com
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 41175067 and 41305056), the National Basic Research Program of China (Grant No. 2012CB955901), the Special Scientific Research Project for Public Interest of China (Grant No. GYHY201506001), and the Special Fund for Climate Change of China Meteorological Administration (Grant No. CCSF201525).

摘要: In recent years, the phenomenon of a critical slowing down has demonstrated its major potential in discovering whether a complex dynamic system tends to abruptly change at critical points. This research on the Pacific decadal oscillation (PDO) index has been made on the basis of the critical slowing down principle in order to analyze its early warning signal of abrupt change. The chaotic characteristics of the PDO index sequence at different times are determined by using the largest Lyapunov exponent (LLE). The relationship between the regional sea surface temperature (SST) background field and the early warning signal of the PDO abrupt change is further studied through calculating the variance of the SST in the PDO region and the spatial distribution of the autocorrelation coefficient, thereby providing the experimental foundation for the extensive application of the method of the critical slowing down phenomenon. Our results show that the phenomenon of critical slowing down, such as the increase of the variance and autocorrelation coefficient, will continue for six years before the abrupt change of the PDO index. This phenomenon of the critical slowing down can be regarded as one of the early warning signals of an abrupt change. Through calculating the LLE of the PDO index during different times, it is also found that the strongest chaotic characteristics of the system occurred between 1971 and 1975 in the early stages of an abrupt change (1976), and the system was at the stage of a critical slowing down, which proves the reliability of the early warning signal of abrupt change discovered in 1970 from the mechanism. In addition, the variance of the SST, along with the spatial distribution of the autocorrelation coefficient in the corresponding PDO region, also demonstrates the corresponding relationship between the change of the background field of the SST and the change of the PDO.

关键词: abrupt climate change, critical slowing down, early warning signals, largest Lyapunov exponent, sea surface temperature

Abstract: In recent years, the phenomenon of a critical slowing down has demonstrated its major potential in discovering whether a complex dynamic system tends to abruptly change at critical points. This research on the Pacific decadal oscillation (PDO) index has been made on the basis of the critical slowing down principle in order to analyze its early warning signal of abrupt change. The chaotic characteristics of the PDO index sequence at different times are determined by using the largest Lyapunov exponent (LLE). The relationship between the regional sea surface temperature (SST) background field and the early warning signal of the PDO abrupt change is further studied through calculating the variance of the SST in the PDO region and the spatial distribution of the autocorrelation coefficient, thereby providing the experimental foundation for the extensive application of the method of the critical slowing down phenomenon. Our results show that the phenomenon of critical slowing down, such as the increase of the variance and autocorrelation coefficient, will continue for six years before the abrupt change of the PDO index. This phenomenon of the critical slowing down can be regarded as one of the early warning signals of an abrupt change. Through calculating the LLE of the PDO index during different times, it is also found that the strongest chaotic characteristics of the system occurred between 1971 and 1975 in the early stages of an abrupt change (1976), and the system was at the stage of a critical slowing down, which proves the reliability of the early warning signal of abrupt change discovered in 1970 from the mechanism. In addition, the variance of the SST, along with the spatial distribution of the autocorrelation coefficient in the corresponding PDO region, also demonstrates the corresponding relationship between the change of the background field of the SST and the change of the PDO.

Key words: abrupt climate change, critical slowing down, early warning signals, largest Lyapunov exponent, sea surface temperature

中图分类号:  (Abrupt/rapid climate change)

  • 92.70.Aa