Paleoenvironmental Dynamics in the Southern Hemisphere and Ocean

Paleoenvironmental research in the Southern Hemisphere and the adjacent oceans has unveiled the complex interplay between climate forcing, cryospheric change and ecosystem response over millennial to sub-millennial timescales. A variety of natural archives—ice cores, marine and lacustrine sediments, speleothems and geomorphological features—record past variations in temperature, sea-ice extent, carbon cycling and hydrology. These records reveal, for example, the sensitivity of Antarctic sea ice to changes in wind patterns and polynya efficiency, the role of temperature in regulating dissolved organic carbon release from mountain catchments in New Zealand, and the impact of meltwater fluxes and proglacial lakes on glacier retreat. Together, these findings inform our understanding of Southern Hemisphere teleconnections such as shifts in the Southern Westerlies and El Niño–Southern Oscillation, and underpin improved model projections of future sea-level rise, carbon-cycle feedbacks and ecosystem resilience.

Research from Nature Portfolio

Reconstructions of dissolved organic carbon (DOC) export from pristine alpine soils in New Zealand use speleothems and lake-sediment cores spanning the past 14,000 years. These studies demonstrate that warmer intervals, notably the Holocene Climatic Optimum, doubled to tripled allochthonous DOC flux via enhanced microbial degradation and vegetation inputs, signalling potential amplification of carbon release under future warming. In the Ross Sea, combined analyses of marine diatoms and sea-salt and isotope signals from ice cores have traced Holocene sea-ice variability. Since around 3,600 years before present, increased efficiency of wind-driven latent-heat polynyas has generated more persistent coastal sea ice even as overall extent declined, exerting marked influence on marine ecosystems and biogeochemical cycles.

Paleoenvironmental Dynamics in the Southern Hemisphere and Ocean publication trend

The graph below shows the total number of articles in paleoenvironmental dynamics in the southern hemisphere and ocean across all publications each year (not limited to Nature Index journals).

Technical terms

Proxy: An indirect measure of past environmental conditions derived from natural archives such as sediments, ice cores or biological remains.

Speleothem: Mineral deposits, typically stalagmites or stalactites, formed in caves that preserve geochemical signatures of past climate.

Polynya: An area of open water surrounded by sea ice, often maintained by winds or currents, which influences local heat exchange and marine productivity.

Dissolved organic carbon (DOC): Organic molecules in water originating from soils or organic matter degradation, important for the carbon cycle and water quality.

Marine sedimentary record: Layers of deposited material on the ocean floor that archive past changes in sediment supply, biological productivity and ocean circulation.

References

1. Warming drives dissolved organic carbon export from pristine alpine soils. Nature Communications (2024).
2. Antarctic Sea Ice Proxies from Marine and Ice Core Archives Suitable for Reconstructing Sea Ice over the Past 2000 Years. Geosciences (2019).
3. Holocene sea ice variability driven by wind and polynya efficiency in the Ross Sea. Nature Communications (2017).
4. Ice-contact proglacial lakes associated with the Last Glacial Maximum across the Southern Alps, New Zealand. Quaternary Science Reviews (2019).