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

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 (Delta LOD) 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 Delta LOD. Finally, the anomalies during the period of 1993-2023 were focused on, by comparing the high-precision fluid forcing and the climate-related Delta LOD with El Nino-Southern Oscillation (ENSO) indices. Our results show that superimposing the HAM can improve fluid correlations similar to 5% with climate-related Delta LOD, but the OAM contribution is not obvious. Additionally, we detected a triple-dip La Nina in the last 3 years, and the corresponding minimum values of climate-related Delta LOD were between -0.11 and -0.23 ms. Furthermore, we investigated the short-term forecast of a climate event with Delta LOD predictions based on the climate change information on Earth's rotation rate, wherein a follow-up El Nino is indicated.