Future changes in marine heatwaves based on high-resolution ensemble projections for the northwestern Pacific Ocean

• Published in: Journal of oceanography Vol. 80; no. 3; pp. 177 - 195
• Main Authors: Kawakami, Yuma, Nakano, Hideyuki, Urakawa, L. Shogo, Toyoda, Takahiro, Sakamoto, Kei, Nishikawa, Shiro, Sugiyama, Toru, Kurogi, Masao, Ishikawa, Yoichi, Sato, Katsunari, Yamanaka, Goro
• Format: Journal Article
• Language: English
• Published: Singapore Springer Nature Singapore 01-06-2024; Springer Nature B.V
• Subjects: 21st century; Anomalies; Carbon dioxide; Carbon dioxide emissions; Climate change; Earth and Environmental Science; Earth Sciences; Emission; Fisheries; Freshwater & Marine Ecology; Fronts; Global warming; Heat waves; Heatwaves; High resolution; High seas; Marine ecosystems; Mitigation; Ocean models; Oceanography; Original Article; Sea surface; Sea surface temperature; Surface temperature; Variability; Pacific Ocean; High-resolution ocean model simulations; The northwestern Pacific Ocean; Global warming; Marine heatwaves; Future projections
• ISSN: 0916-8370; 1573-868X
• DOI: 10.1007/s10872-024-00714-y

Marine heatwaves (MHWs) are oceanic conditions characterized by extremely high sea surface temperature (SST) anomalies that last for several days to years. Because MHWs have devastating effects on marine ecosystems and significant impacts on fisheries, understanding future MHWs is important for adapting to upcoming climate changes. In this study, we examined future changes in MHWs in the northwestern Pacific Ocean (18–53ºN, 117ºE–170ºW) under two CO
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emission scenarios using a high-resolution ensemble (four members for each scenario) simulation product using a high-resolution ocean model that satisfactorily resolves the Kuroshio, Kuroshio Extension, and SST fronts. Following global warming, MHWs based on a threshold in the historical period (1981–2005) will increase and intensify (i.e., occur with higher SST anomalies than before). In the historical period, the annual MHW days ranged from 20 to 34 days. Annual MHW days increase to 63–313 days (188 days–all year round) depending on the region under the high CO
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mitigation (emission) scenario at the end of the twenty-first century of 2076–2100. Furthermore, we investigated the spatial details of future MHWs. Future MHWs reflect the magnitude of SST variability in addition to that of sea surface warming in the twenty-first century; future MHWs are less frequent and more intense in the subtropical–subarctic frontal zone with large SST variability than in other regions.