Abstract
Aerial rivers, long-term preferential pathways of atmospheric moisture flows, sustain ecosystems and regional hydrology. Maximizing their downwind discharge potential remains elusive without an objective way to identify critical upwind source regions. Here we analyze the drainage patterns of aerial rivers across South America and develop a mathematical method to identify turning points in moisture drainage curves, beyond which the intensity of upwind moisture contribution declines sharply. This provides a criterion for objectively delineating critical upwind basins and reveals pronounced continental variation in their spatial extent. These patterns reflect distinct regimes within the continental aerial river system, enabling its classification into four major drainage types: headwater, drainage, outfall, and plain areas. The four types differ in their potential for atmospheric moisture management and in their susceptibility to ecological tipping points, with implications for refining forest conservation priorities. Together, these findings support more effective land-water planning and moisture governance under a changing climate.
Acknowledgements
The authors acknowledge M. K. B. Luedeke, Y. C. Liang, A. Crivellari, C. Huang, and Y. R. Chuang for discussions during the earlier stages of this study. The authors thank M. Y. Liu, C. W. Ho, Z. F. Chen, and S. Lee for their assistance with data visualization; C. H. Shih, C. K. Chiu, and Y. C. Liu for their help in acquiring data.
Funding
This work was supported by the National Science and Technology Council (NSTC) Taiwan grant 112-2410-H-002-255-MY2 (W.W. and P.F.). Y.-M.H., H.T.H., and L.-P.W. were financially supported by NSTC Taiwan grant 113-2923-M-002-001-MY4. K.-C.T. acknowledges support from the Ministry of Education, Taiwan, under grant 113V1017-3. M.-H.L. was supported by NSTC Taiwan grant 114-2811-M-002-128 and 115-2111-M-002-003.
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Weng, W., Fu, P., Hung, H.T. et al. Hydrological regimes and drainage systems of aerial rivers across South America.
Nat Commun (2026). https://doi.org/10.1038/s41467-026-76303-y
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DOI: https://doi.org/10.1038/s41467-026-76303-y
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