Interannual variability and trends of sea surface temperature around southern South America

A study of sea surface temperature (SST) around southern South America from 1982 to 2017 reveals divergent trends: moderate to intense warming in mid-latitude regions (30°–50°S) and moderate cooling south of 50°S. Significant opposite trends were identified on the Patagonian Shelf, with the Northern Patagonian Shelf warming and the Southern Patagonian Shelf cooling, primarily driven by variability between 2008 and 2017.

• Between 1982 and 2017, sea surface temperature (SST) trends around southern South America varied by latitude: mid-latitude regions (30°–50°S) in the eastern South Pacific and western South Atlantic experienced moderate to intense warming of approximately 0.4°C per decade, whereas regions south of 50°S experienced moderate cooling of approximately -0.3°C per decade.
• The Patagonian Shelf in the southwest South Atlantic exhibits two areas of statistically significant SST anomaly trends with opposite signs. The Northern Patagonian Shelf (NPS), located between 42 and 45°S, warmed at a rate of 0.15 ± 0.01°C per decade (a total increase of 0.52°C), while the Southern Patagonian Shelf (SPS), located between 49 and 52°S, cooled at a rate of -0.12 ± 0.01°C per decade (a total decrease of 0.42°C). These trends were primarily driven by variability between 2008 and 2017, as trends from 1982 to 2007 were non-significant.
• Interannual variability of SST anomalies around southern South America is linked to atmospheric forcing and large-scale climate modes. Local meridional wind explained 25–30% of total variance at the NPS and SPS from 1982 to 2007. From 2008 to 2017, SST anomalies at the NPS were significantly anticorrelated with local zonal wind (r = -0.85), and at the SPS they were anticorrelated with meridional wind (r = -0.61). The first three empirical orthogonal function (EOF) modes explain 28%, 16%, and 12% of the variance, respectively, and are associated with the Southern Annular Mode, the Interdecadal Pacific Oscillation, and El Niño–Southern Oscillation.

APA

Inter-American Institute for Global Change Research (2025). Interannual variability and trends of sea surface temperature around southern South America. https://iai.int/es/pub_acad/interannual-variability-and-trends-of-sea-surface-temperature-around-southern-south-america/

Chicago

Inter-American Institute for Global Change Research. Interannual variability and trends of sea surface temperature around southern South America. 2025. https://iai.int/es/pub_acad/interannual-variability-and-trends-of-sea-surface-temperature-around-southern-south-america/.

Wikipedia

{{cite report |author=Inter-American Institute for Global Change Research |title=Interannual variability and trends of sea surface temperature around southern South America |date=6 January 2025 |url=https://iai.int/es/pub_acad/interannual-variability-and-trends-of-sea-surface-temperature-around-southern-south-america/ |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{interamericaninstituteforglobalchangeresearch2025interannual, author = {{Inter-American Institute for Global Change Research}}, title = {{Interannual variability and trends of sea surface temperature around southern South America}}, institution = {Inter-American Institute for Global Change Research}, year = {2025}, month = jan, url = {https://iai.int/es/pub_acad/interannual-variability-and-trends-of-sea-surface-temperature-around-southern-south-america/}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }