Paleoclimate Dynamics in Southern South America

Southern South America, dominated by the Patagonian Andes and adjacent ocean basins, has long been a focal point for understanding how mid-latitude wind systems, ice sheets and ocean currents interact over glacial–interglacial and Holocene timescales. The advance and retreat of the Patagonian Ice Sheet has been closely tied to fluctuations in the Southern Westerly Winds, which regulate precipitation distribution, temperature gradients and Southern Ocean upwelling. Multiproxy records drawn from lake sediments, marine cores and cosmogenic nuclide dating have revealed rapid millennial-scale ice-sheet responses to shifts in atmospheric circulation, as well as longer-term trends linked to orbital forcing and solar variability. During the Holocene, poleward migrations of wind belts and episodic Southern Annular Mode-like events have driven centennial changes in glacier mass balance and regional hydrology. Insights gleaned from this region are of global significance, informing projections of sea-level rise, carbon cycle feedbacks and the future behaviour of mid-latitude cryospheric systems under ongoing anthropogenic warming.

Research from Nature Portfolio

Recent studies have reconstructed an ~11,000-year record of sea-salt aerosol and geochemical indicators in lake sediments at Cape Horn, demonstrating that the Southern Westerly Winds were displaced poleward during the Early Holocene peak warmth. This finding provides a palaeo-analogue for future wind-belt shifts under continued global warming and underscores potential impacts on high-latitude climate and ocean circulation. Complementary work on sub-Antarctic Marion Island has yielded a 700-year diatom and geochemical archive of wind-driven changes in diatom assemblages and geochemical proxies, revealing that cooler periods coincide with equatorward wind shifts while warmer intervals drive intensification and poleward migration of the winds. These centennial-scale wind migrations closely mirror reconstructed temperature gradients and highlight the sensitivity of atmospheric circulation to latitudinal thermal contrasts. Additionally, sediment records from Chilean Patagonia have uncovered Southern Annular Mode-like fluctuations over the past 10,000 years, linking positive SAM-like phases to reduced precipitation and glacier minima, and negative phases to enhanced westerlies and ice-growth intervals during the Neoglaciations.

Paleoclimate Dynamics in Southern South America publication trend

The graph below shows the total number of articles in paleoclimate dynamics in southern south america across all publications each year (not limited to Nature Index journals).

Technical terms

Southern Westerly Winds (SWW): Prevailing mid-latitude wind belt encircling the Southern Hemisphere, crucial for moisture transport and ocean mixing.

Southern Annular Mode (SAM): Principal mode of atmospheric variability in the Southern Hemisphere, defined by pressure differences between mid- and high latitudes.

Multiproxy: Use of multiple independent archives (e.g., biological, geochemical, isotopic) to reconstruct past environmental conditions.

Cosmogenic nuclide dating: Technique that measures rare isotopes produced by cosmic rays to determine exposure ages of surface samples, often used in glacial histories.

Marine Isotope Stage (MIS): Alternating warm and cold periods in Earth’s history, inferred from oxygen isotope ratios in marine carbonates.

References

1. A marine record of Patagonian ice sheet changes over the past 140,000 years. Proceedings of the National Academy of Sciences of the United States of America (2024).
2. Poleward displacement of the Southern Hemisphere Westerlies in response to Early Holocene warming. Communications Earth & Environment (2025).
3. Solar Cycles Forced Southern Westerly Wind Migrations During the Holocene. Geophysical Research Letters (2023).
4. Modeling the timing of Patagonian Ice Sheet retreat in the Chilean Lake District from 22–10 ka. The Cryosphere (2024).
5. Onset and Evolution of Southern Annular Mode-Like Changes at Centennial Timescale. Scientific Reports (2018).