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Abstract Lake surface temperature extremes have shifted over recent decades, leading to significant ecological and economic impacts. Here, we employed a hydrodynamic-ice model, driven by climate data, to reconstruct over 80 years of lake surface temperature data across the world’s largest freshwater bodies. We analyzed lake surface temperature extremes by examining changes in the 10th and 90th percentiles of the detrended lake surface temperature distribution, alongside heatwaves and cold-spells. Our findings reveal a 20–60% increase in the 10 and 90 percentiles detrended lake surface temperature in the last 50 years relative to the first 30 years. Heatwave and cold-spell intensities, measured via annual degree days, showed strong coherence with the Arctic Oscillation (period: 2.5 years), Southern Oscillation Index (4 years), and Pacific Decadal Oscillation (6.5 years), indicating significant links between lake surface temperature extremes and both interannual and decadal climate teleconnections. Notably, heatwave and cold-spell intensities for all lakes surged by over 100% after 1996 or 1976, aligning with the strongest El-Niño and a major shift in the Pacific Decadal Oscillation, respectively, marking potential regional climate tipping points. This emphasizes the long-lasting impacts of climate change on large lake thermodynamics, which cascade through larger ecological and regional climate systems.
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This content will become publicly available on July 28, 2026
The Spatiotemporal Dynamics of Heatwaves and Cold‐Spells in Earth's Largest Freshwater Systems
Abstract Extreme water temperatures impact the ecological and economic value of freshwater systems. They disrupt fisheries habitat, trigger harmful algal blooms, and stress coastal infrastructure. This study examines the spatiotemporal patterns of heatwaves and cold‐spells in the Great Lakes using 82 years of simulated surface temperature data. Significant increasing trends in heatwave duration were observed in Lake Superior and Lake Michigan‐Huron, while cold‐spell duration increased on all lakes except Ontario. Temperature anomalies during these events varied from the climatological mean by as much as ±10C, but did not change significantly over time. Analysis revealed substantial spatial variability in heatwaves and cold‐spells, both within and across lakes, with differences driven by air temperature and ice cover anomalies as well as associated climate teleconnections (i.e., the East Pacific/North Pacific and Atlantic Multidecadal Oscillation). These findings highlight the importance of both climatic and lake processes in shaping extreme temperature events.
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- PAR ID:
- 10648159
- Publisher / Repository:
- AGU Advancing Earth and Space Sciences
- Date Published:
- Journal Name:
- Geophysical Research Letters
- Volume:
- 52
- Issue:
- 14
- ISSN:
- 0094-8276
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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