Cryospheric Excitation on the Earth's Chandler Wobble and Implications From a Warming World

Abstract

Leveraging Gravity Recovery and Climate Experiment mascon products spanning from April 2002 to September 2023, we, for the first time, ascertain the substantial influence of cryospheric mass variations on Earth's Chandler wobble (CW). Further, in contrast to traditional analysis conducted in the excitation domain, this study focuses on the polar motion domain and incorporates the wavelet analysis technique. Our findings reveal some intriguing phenomena: Between 2006 and 2020, the cryosphere contributed an average amplitude of approximately 4.85 mas to CW, equivalent to 5.05%, with its impact escalating to about 11 mas from 2018 to 2022, representing a fourfold rise in its contribution ratio to approximately 20%. This marked surge can be attributed to the more erratic glacier mass balance results from ongoing climate change. Moreover, there is a pronounced decrease in the CW signal post-2018, which starkly contrasts with cryospheric contribution, suggesting a potential linkage to climate change yet warrants further investigation.