A study of the relationship between GRACE-TWSA and large-scale atmospheric-oceanic patterns

Abstract

This study aims to investigate the connections between changes in the Total Water Storage Anomaly (TWSA) associated with 12 continental/subcontinental regions derived from the Gravity Recovery and Climate Experiment (GRACE) satellite and 25 different Large-Scale Climate Oscillation Indices (LSCOI). Initially, correlation analyses were performed and then the principal component analyses together with wavelet coherent transform were employed in the analyses. The results explain over 50% of TWSA variability, with the Pacific and Indian Oceans exerting strong influence. While Southern Hemisphere regions display consistent long-term relationships with LSCOI patterns, the Northern Hemisphere exhibits more complex dynamics, including trade-offs between leading and lagging effects and in-phase versus anti-phase states. Random Forest and M5 Tree models were then applied using high-correlation LSCOIs as predictors for regional TWSAs. Results of models confirmed the robustness of the identified teleconnections and demonstrated the potential for predicting regional water storage anomalies using climate oscillation indices.