Rapid decline in extratropical Andean snow cover driven by the poleward migration of the Southern Hemisphere westerlies
Seasonal snow in the extratropical Andes is a primary water source for major rivers supplying water for drinking, agriculture, and hydroelectric power in Central Chile. Here, we used estimates from the Moderate Resolution Imaging Spectroradiometer (MODIS) to analyze changes in snow cover extent over the period 2001–2022 in a total of 18 watersheds spanning approximately 1,100 km across the Chilean Andes (27–36°S). We found that the annual snow cover extent is receding in the watersheds analyzed at an average pace of approximately 19% per decade. These alarming trends have impacted meltwater runoff, resulting in historically low river streamflows during the dry season. We examined streamflow records dating back to the early 1980s for 10 major rivers within our study area. Further comparisons with large-scale climate modes suggest that the detected decreasing trends in snow cover extent are likely driven by the poleward migration of the westerly winds associated with a positive trend in the Southern Annular Mode (SAM).
Authors
- Jorge Carrasco (ORCID: https://orcid.org/0000-0003-2154-5483)
- Chenghao Wang (ORCID: https://orcid.org/0000-0001-8846-4130)
- Cyrus Karas (ORCID: https://orcid.org/0000-0002-7436-5016)
- Edgardo Sepúlveda
- Alessandro Damiani (ORCID: https://orcid.org/0000-0003-3014-6193)
- Alia L. Khan (ORCID: https://orcid.org/0000-0002-4425-1528)
- Sarah Féron (ORCID: https://orcid.org/0000-0002-0572-5639)
- Francisco Fernandoy (ORCID: https://orcid.org/0000-0003-2252-7746)
- Gino Casassa (ORCID: https://orcid.org/0000-0002-7888-071X)
- Raúl R. Cordero (ORCID: https://orcid.org/0000-0001-7607-7993)
- Jaime Pizarro (ORCID: https://orcid.org/0000-0001-6132-6117)
- Fernanda Cabello
- Shelley MacDonell
- José Jorquera
Institutions
- Universidad de Santiago de Chile (CL)
- University of Arizona (US)
- Universidad Andrés Bello (CL)
- Cooperative Institute for Research in Environmental Sciences (US)
- University of Groningen (NL)
- National Institute for Environmental Studies (JP)
- Universidad Bernardo O'Higgins (CL)
- Centro de Recursos Educativos Avanzados (CL)
- Western Washington University (US)
- Universidad de Magallanes (CL)
- Rogers (United States) (US)
- University of Oklahoma (US)
Publication Details
- Journal
- Scientific Reports
- Published
- 2024-11-11
- DOI
- https://doi.org/10.1038/s41598-024-78014-0
- Citations
- 5
- Primary Topic
- Cryospheric studies and observations
- Type
- article
- Field-Weighted Citation Impact
- 1.88
Funders
- Agencia Nacional de Investigación y Desarrollo
- European Centre for Medium-Range Weather Forecasts
- National Oceanic and Atmospheric Administration
- Departamento de Investigaciones Científicas y Tecnológicas, Universidad de Santiago de Chile