Zhu et al. (2025) Revisiting the Relationship Between Changes in Global‐Mean Surface Air Temperature and Sea Surface Temperature at the Last Glacial Maximum

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Geophysical Research Letters
• Year: 2025
• Date: 2025-12-20
• Authors: Chenyu Zhu, Yahui Jin
• DOI: 10.1029/2025gl118083

Research Groups

Not explicitly stated in the provided abstract.

Short Summary

This study investigates the ratio of global mean air versus sea surface temperature change (S) during the Last Glacial Maximum (LGM) using reconstructions and model simulations, finding S to be 1.97 ± 0.22, significantly higher than under future warming due to ice sheets, and negatively related to sea surface cooling.

Objective

• To investigate the ratio of global mean air versus sea surface temperature change (S) during the Last Glacial Maximum (LGM) and understand its relationship with climate background.

Study Configuration

• Spatial Scale: Global mean
• Temporal Scale: Last Glacial Maximum (LGM)

Methodology and Data

• Models used: Climate model simulations (specific models not named)
• Data sources: Paleoclimate reconstructions

Main Results

• The simulated ratio of global mean air versus sea surface temperature change (S) at the LGM is 1.97 ± 0.22 (1σ).
• This LGM S value is 44 ± 16% greater than S under future warming scenarios.
• The primary reason for this difference is attributed to the influence of elevated continental ice sheets.
• The glacial air-sea cooling contrast is negatively related to the magnitude of sea surface cooling, consistent with a simple moist static energy theory.
• This relationship can be used to constrain S, further suggesting a median LGM surface cooling of -5.6 °C.

Contributions

• Quantifies the global mean air versus sea surface temperature change ratio (S) for the Last Glacial Maximum (LGM).
• Identifies elevated continental ice sheets as a key driver for the significant difference in S between glacial and future warming climates.
• Establishes a relationship between glacial air-sea cooling contrast and sea surface cooling, providing a new method to constrain S.
• Provides a new estimate for median LGM surface cooling (-5.6 °C).
• Cautions against the use of a fixed S value across different climate backgrounds, emphasizing its implications for paleotemperature reconstructions and climate projections.

Funding

Not explicitly stated in the provided abstract.

Citation

@article{Zhu2025Revisiting,
  author = {Zhu, Chenyu and Jin, Yahui},
  title = {Revisiting the Relationship Between Changes in Global‐Mean Surface Air Temperature and Sea Surface Temperature at the Last Glacial Maximum},
  journal = {Geophysical Research Letters},
  year = {2025},
  doi = {10.1029/2025gl118083},
  url = {https://doi.org/10.1029/2025gl118083}
}