Interannual Variation in Earth’s Rotation Rate and Its Role as a Climate Change Indicator

Abstract

Exploring the relationship between climate phenomena and anomalies in Earth’s rotation during a corresponding period is helpful for constraining the assessment of global change, even for the early warning of climate events. This study selected the latest length of day changes (ΔLOD) observations, and extracted the interannual terms solely related to climatic variations, employing a difference plus frequency domain stepwise regression (Difference+FDSR) method. Afterward, we calculated the correlations of different data compositions between surface fluid contributions (AAM, OAM and HAM) and the climate-related ΔLOD. Finally, the anomalies during the period of 1993–2023 were focused on, by comparing the high-precision fluid forcing and the climate-related ΔLOD with El Niño–Southern Oscillation (ENSO) indices. Our results show that superimposing the HAM can improve fluid correlations ~5% with climate-related ΔLOD, but the OAM contribution is not obvious. Additionally, we detected a triple-dip La Niña in the last 3 years, and the corresponding minimum values of climate-related ΔLOD were between −0.11 and −0.23 ms. Furthermore, we investigated the short-term forecast of a climate event with ΔLOD predictions based on the climate change information on Earth‘s rotation rate, wherein a follow-up El Niño is indicated.