Towards a new paleotemperature proxy from reef coral occurrences

Area of Science:

• Paleoclimatology
• Marine Biology
• Climate Modeling

Background:

• The last interglacial episode (LIG) is a key period for understanding past global warming.
• Robust paleoclimate data from low latitudes during the LIG are scarce.
• Tropical reef corals can serve as valuable proxies for past sea-surface temperatures.

Purpose of the Study:

• To reconstruct low-latitude sea-surface temperatures during the LIG using coral distribution data.
• To investigate the spatial patterns of temperature anomalies during the LIG.
• To assess changes in the habitable zone for reef corals during this period.

Main Methods:

• Developed a geographically explicit model of sea-surface temperatures based on modern reef coral distributions.
• Applied the developed model to fossil coral occurrence data from the LIG.
• Analyzed the resulting latitudinal patterns of sea-surface temperature anomalies.

Main Results:

• A distinct U-shaped pattern of temperature anomalies was observed across latitudes during the LIG.
• Temperatures near the equator were cooler than present-day levels.
• Subtropical regions exhibited warmer-than-present temperatures during the LIG.

Conclusions:

• The findings support previous estimates of LIG temperatures.
• Reef coral habitats likely expanded poleward during the LIG.
• Coral occurrence data provides a reliable method for paleoclimate reconstructions in low latitudes.