The global 64-year sea level oscillation and its possible external excitation sources  

作　　者：Mingyu XIAO Taoyong JIN Hao DING Lianjun YANG Xiaolong LI Jiancheng LI 

机构地区：[1]School of Geodesy and Geomatics,Wuhan University,Wuhan 430079,China [2]MOE Key Laboratory of Geospace Environment and Geodesy,Wuhan University,Wuhan 430079,China

出　　处：《Science China Earth Sciences》2025年第3期898-908,共11页中国科学(地球科学英文版)

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 42388102, 42192531 & 42374035);the Fundamental Research Funds for the Central Universities (Grant No. 2042023kfyq01);the Special Fund of Hubei Luojia Laboratory (Grant Nos. 220100001 & 220100002)。

摘　　要：Low-frequency signals play an important role in understanding sea level changes and their acceleration. This paper analyzed multidecadal oscillations on a global scale with tide gauge records. A significant stable oscillation of approximately64 years was identified at 177 globally distributed tide gauges, with an estimated period of 63±4 yr. The amplitude of this oscillation depends on latitude, whereas the phase depends on longitude. The regions most affected(up to ~20 mm) by the 64-yr oscillation include Europe, North America, South Australia, and East Asia. Our results are consistent with the spherical harmonic model, indicating that the 64-yr oscillation is not a random or irregular signal but rather a global signal likely excited by a specific source. To explore the possible excitation sources, we analyzed several external factors closely related to sea level change(where“external” refers to factors relative to the Earth's interior), including thermosteric sea level, ocean mass change, precipitation, sea level pressure, surface temperature, sunspot numbers, solar flux, and the total solar irradiance index. Our results show that there are significant differences in the periods, amplitudes and phases of the multidecadal characteristics of these datasets from those of the 64-yr oscillation;thus the existence of the 64-yr oscillation was denied in these datasets. Therefore, we firstly confirm that climate change and solar activity cannot explain the 64-yr sea level oscillation.

关 键 词：Sea level change 64-year oscillation Tide gauge records Solar activity Climate change 

分 类 号：P731.23[天文地球—海洋科学]