Record-breaking 2023 marine heatwaves

2025/07/24 by Tianyun Dong, Zhenzhong Zeng, Ming Pan +14 · 1 voice · 28 citations
Earth and Planetary Sciences · Environmental Science · #Climate change #Climate system #Climate variability and models #Climatology #Environmental science #Geography #Geology #Marine and coastal ecosystems #Oceanographic and Atmospheric Processes #Oceanography

paper · open access · doi:10.1126/science.adr0910

published in Science 389(6758), 369-374 (American Association for the Advancement of Science)

openalex publication_date 2025/07/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/03

Abstract

The year 2023 witnessed an extraordinary surge in marine heatwaves (MHWs) across Earth's oceans, setting new records in duration, extent, and intensity, with MHW activity totaling 53.6 billion °C days square kilometer-more than three standard deviations above the historical norm since 1982. Notable events include the North Atlantic MHW (276-year return period) and the Southwest Pacific (141 years). Using ECCO2 (Estimating the Circulation and Climate of the Ocean-Phase II) high-resolution daily data, we conducted a mixed-layer heat budget analysis and identified region-specific drivers: enhanced shortwave flux and a shallower mixed layer in the North Atlantic and North Pacific, reduced cloud cover and increased advection in the Southwest Pacific, and oceanic advections in the Tropical Eastern Pacific. The 2023 MHWs highlight the intensifying impacts of a warm climate and the challenges in understanding extreme events.

Citations

• The 2023 state of the climate report: Entering uncharted territory
• Recent global temperature surge intensified by record-low planetary albedo
• Tipping elements in the Earth's climate system
• New Record Ocean Temperatures and Related Climate Indicators in 2023

Cited by

• Ocean Heat Content Sets Another Record in 2025
• Ocean acidification, more than warming or heatwaves, constrains shoaling behaviour in a range‐extending fish through habitat simplification
• Reduced aerosol pollution diminished cloud reflectivity over the North Atlantic and Northeast Pacific. [europepmc]
• Coral Bleaching: The Equatorial-Refugia Hypothesis. [europepmc]
• Redundancy of macrobenthic functional traits boosts resilience to a simulated heatwave. [europepmc]

Discussions

• 🌊 2023 marine heatwaves hit record levels, covering 96% of oceans and lasting four times longer. A study in Science explores the complex regional drivers and warns that we may be approaching a climat [bsky, 2 points, 0 comments]

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