1972—2022年地球自转速率的变化特性及其中的气候事件表征研究  

Variation in the rotation rate of Earth and its role as a climate change indicator between 1972 and 2022

作　　者：许雪晴[1,2,3] 周永宏 胥灿灿[1,3] Xu Xueqing;Zhou Yonghong;Xu Cancan(Shanghai Astronomical Observatory,Chinese Academy of Sciences,Shanghai 200030,China;Key Laboratory of Planetary Sciences,Chinese Academy of Sciences,Shanghai 200030,China;School of Astronomy and Space Science,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院上海天文台,上海200030 [2]中国科学院行星科学重点实验室,上海200030 [3]中国科学院大学天文与空间科学学院,北京100049

出　　处：《地球与行星物理论评（中英文）》2023年第5期572-580,共9页Reviews of Geophysics and Planetary Physics

基　　金：国家自然科学基金资助项目(12233010,12173070);中国科学院青年创新促进会资助项目(2019265)。

摘　　要：作为反映地球自转速率累积变化的参数(世界时UT1-UTC)和时变特性的参数(日长变化ΔLOD),UT1-UTC在现实项目中有重要应用,而ΔLOD则主要用于科学研究,联合两者探讨地球自转速率变化的规律有重要的意义.本工作针对近50年的世界时观测数据分析其特性,重点关注近期出现的异常现象:2020年5月以来,地球自转趋势由原来的长期减慢逆转为加快;同时对日长变化序列进行分解,分析地球自转速率变化的可能激发源,并评估其中的气候因素对近期地球自转加快的贡献.结果表明,扣除其他影响因素后,日长年际项与气候变化指数表现出高度的一致性;近三年期间,检测到两次中等强度的拉尼娜事件以及第二次事件的延续,其对近期地球自转加快的贡献大约为9%.The universal time(UT1-UTC) and length of day change(ΔLOD) are two parameters that describe the Earth’s rotation rate variations. UT1-UTC is typically used in space projects, whereas ΔLOD is used for scientific investigations. Therefore, studying the variations between the two parameter sequences is very important.In this study, we reviewed the Earth’s rotation rate over the last five decades and revealed an abnormal phenomenon in UT1-UTC. Since May 2020, the Earth’s rotation has reversed from a deceleration trend to an acceleration trend. Besides, we used ΔLOD to find the possible geophysical contributors and focused on the climate-related contributions. Results revealed that the interannual LOD exhibited a notable degree of consistency with ENSO indices after using the Difference+FDSR method to remove the internally and externally induced signals. Notably,two La Nina with intermediate strength and the beginning of a closely followed third trough were detected in the last three years. The contributions of these events to the latest rotation acceleration are approximately 9%.

关 键 词：地球自转速率变化 气候变化 厄尔尼诺 拉尼娜 

分 类 号：P183.3[天文地球—天文学]