Pacific sea surface temperatures affect Andean snowpack and water supply to the semi-arid central Chile and Argentina

The document identifies a strong correlation between Pacific sea surface temperature patterns and water availability in the Andes of central Chile and Argentina. It highlights that El Niño years typically correspond with high snowpack and streamflow, while La Niña years often align with low levels. Furthermore, the document links multi-decadal shifts in the Pacific Decadal Oscillation (PDO) to significant changes in mean annual river discharges, suggesting that the interplay between ENSO and PDO is critical for forecasting future water scarcity.

• Andean snowmelt is the primary water source for ecosystems, industry, hydropower, agriculture, and households in central-western Argentina and semi-arid central Chile, with a close relationship between regionally averaged snowpack and streamflow indicating that snowmelt generates most of the annual streamflow in this region.
• Winter snowpack and streamflow levels are linked to the El Niño-Southern Oscillation (ENSO), where warm El Niño events in the tropical Pacific coincide with high snowpack and streamflow, and cold La Niña events generally correspond with extreme dry years, although 1968, 1990, and 2004 were exceptions.
• The Pacific Decadal Oscillation (PDO) drives low-frequency hydrologic variations in the Andes of central Chile and Argentina; specifically, PDO shifts in the mid-1940s and 1976-77 coincided with a 27% decrease in 1945 and a 28% increase in 1977 in mean annual river discharges.
• Regional streamflow records in the late 1990s did not match lower PDO values, which the authors suggest might be due to an increasing contribution from melting glaciers, though more data is needed to confirm this.

APA

Inter-American Institute for Global Change Research (2024). Pacific sea surface temperatures affect Andean snowpack and water supply to the semi-arid central Chile and Argentina. https://iai.int/en/la-temperatura-de-la-superficie-del-oceano-pacifico-afecta-la-capa-de-nieve-de-los-andes-y-el-aporte-de-agua-a-las-regiones-semiaridas-del-centro-de-chile-y-argentina/

Chicago

Inter-American Institute for Global Change Research. Pacific sea surface temperatures affect Andean snowpack and water supply to the semi-arid central Chile and Argentina. 2024. https://iai.int/en/la-temperatura-de-la-superficie-del-oceano-pacifico-afecta-la-capa-de-nieve-de-los-andes-y-el-aporte-de-agua-a-las-regiones-semiaridas-del-centro-de-chile-y-argentina/.

Wikipedia

{{cite report |author=Inter-American Institute for Global Change Research |title=Pacific sea surface temperatures affect Andean snowpack and water supply to the semi-arid central Chile and Argentina |date=8 October 2024 |url=https://iai.int/en/la-temperatura-de-la-superficie-del-oceano-pacifico-afecta-la-capa-de-nieve-de-los-andes-y-el-aporte-de-agua-a-las-regiones-semiaridas-del-centro-de-chile-y-argentina/ |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{interamericaninstituteforglobalchangeresearch2024pacific, author = {{Inter-American Institute for Global Change Research}}, title = {{Pacific sea surface temperatures affect Andean snowpack and water supply to the semi-arid central Chile and Argentina}}, institution = {Inter-American Institute for Global Change Research}, year = {2024}, month = oct, url = {https://iai.int/en/la-temperatura-de-la-superficie-del-oceano-pacifico-afecta-la-capa-de-nieve-de-los-andes-y-el-aporte-de-agua-a-las-regiones-semiaridas-del-centro-de-chile-y-argentina/}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }