Significant Shifts in Continental Precipitation Sources in the 21st Century

• Published in: Water Resources Research
• Main Authors: Xingxing Zhang, Hua Wu, Lan Wang Erlandsson, Zhaofei Liu, Hou Jiang, Zhaocai Wang, Liguang Jiang, Yizhu Zhu, Yaozhi Jiang, Zhijun Yao, Zhaoliang Li
• Format: Article
• Language: English
• Published: Wiley 2025-11-01
• Subjects: continental precipitation; moisture sources; climate indexes; major volcano eruption
• Online Access: https://doi.org/10.1029/2025WR040157
• ISSN: 0043-1397; 1944-7973

Abstract Continental precipitation patterns have undergone profound changes in the 21st century, characterized by an increasing dominance of oceanic moisture sources over terrestrial ones. Using the WAM‐2layers (Water Accounting Model‐2 layers) moisture tracking model and ERA5 reanalysis data (1941–2023), we identified a significant upward trend in ocean‐derived moisture, particularly from the Pacific and Atlantic Oceans, with an increase of 0.58 mm yr−2 since 2001. This corresponds to a 3.69% increase in the 2001–2023 mean relative to the 1941–1960 baseline, underscoring the growing influence of oceanic sources. In contrast, terrestrial contributions over the same period exhibited a significant declining trend of −0.38 mm yr−2 (p < 0.01), representing a 2.36% decrease in the mean contribution compared to the 1941–1960 baseline. Critical regions such as the Amazon and Southeast Asia experienced the most pronounced reductions. Analysis across Köppen climate zones reveals a distinct shift toward oceanic dominance in tropical and mid‐latitude regions, while high‐latitude areas exhibit variable trends. These changes are further influenced by major climate patterns (e.g., ENSO, NAO, IOD) and extreme events, including volcanic eruptions, which have reshaped global precipitation dynamics. Our findings highlight the increasing reliance on oceanic moisture sources and the growing vulnerability of land‐based moisture contributions, emphasizing the urgent need for adaptive water resource management strategies to address the evolving hydrological patterns driven by climate change.