Interannual Variability and Trends of Sea Surface Temperature Around Southern South America

This study presents a comprehensive analysis of sea surface temperature (SST) interannual variability and trends around southern South America from 1982 to 2017 using the Optimally Interpolation SST version 2 gridded database. The research reveals significant regional contrasts in temperature trends across this climatically important region.

Key Findings:

Regional Temperature Trends:

• Mid-latitude regions (30°–50°S) in the eastern South Pacific and western South Atlantic show moderate to intense warming (~0.4°C decade⁻¹)
• South of 50°S, the region around southern South America presents moderate cooling (~−0.3°C decade⁻¹)

Patagonian Shelf Patterns:

• Northern Patagonian Shelf (NPS, 42-45°S): Significant warming at 0.15 ± 0.01°C decade⁻¹ (0.52°C total increase)
• Southern Patagonian Shelf (SPS, 49-52°S): Significant cooling at −0.12 ± 0.01°C decade⁻¹ (0.42°C total decrease)
• Strongest trends observed during 2008-2017 period

Climate Variability:

• Spectral analysis reveals significant variance at ~6-year interannual timescales
• Three EOF modes explain 56% of total variance (28%, 16%, and 12% respectively)
• Variability linked to ENSO, Interdecadal Pacific Oscillation, and Southern Annular Mode

Atmospheric Forcing:

• Local winds explain 25-30% of interannual variance during 1982-2007
• Strong anticorrelations between SST anomalies and wind patterns during 2008-2017
• Surface heat fluxes and wind stress curl show significant regional influences

Methodology:

• Analysis of 36 years of satellite SST data (1982-2017)
• Empirical Orthogonal Function (EOF) analysis
• Spectral analysis and statistical trend detection
• Integration with atmospheric reanalysis data
• Regional focus on Patagonian Shelf dynamics

This research contributes significantly to understanding climate variability in the South Atlantic and provides crucial baseline data for climate change assessment and marine ecosystem management in the region.

Recommended citation: Risaro, D.B., Chidichimo, M.P., Piola, A.R. (2022). "Interannual Variability and Trends of Sea Surface Temperature Around Southern South America." Frontiers in Marine Science. 9:829144.
Download Paper