Changes in ocean heat content (OHC), salinity, and stratification provide critical indicators for changes in Earth’s energy and water cycles. These cycles have been profoundly altered due to the emission of greenhouse gasses and other anthropogenic substances by human activities, driving pervasive changes in Earth’s climate system. In 2022, the world’s oceans, as given by OHC, were again the hottest in the historical record and exceeded the previous 2021 record maximum. According to IAP/CAS data, the 0–2000 m OHC in 2022 exceeded that of 2021 by 10.9 ± 8.3 ZJ (1 Zetta Joules = 1021 Joules); and according to NCEI/NOAA data, by 9.1 ± 8.7 ZJ. Among seven regions, four basins (the North Pacific, North Atlantic, the Mediterranean Sea, and southern oceans) recorded their highest OHC since the 1950s. The salinity-contrast index, a quantification of the “salty gets saltier—fresh gets fresher” pattern, also reached its highest level on record in 2022, implying continued amplification of the global hydrological cycle. Regional OHC and salinity changes in 2022 were dominated by a strong La Niña event. Global upper-ocean stratification continued its increasing trend and was among the top seven in 2022.
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The IAP/CAS analysis is supported by the National Natural Science Foundation of China (Grant Nos. 42122046 and 42076202) and the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB42040402). NCAR is sponsored by the US National Science Foundation. The efforts of Dr. Fasullo in this work were supported by NASA Awards 80NSSC17K0565 and 80NSSC22K0046, and by the Regional and Global Model Analysis (RGMA) component of the Earth and Environmental System Modeling Program of the U.S. Department of Energy’s Office of Biological & Environmental Research (BER) via National Science Foundation IA 1947282.
The efforts of Dr. A. MISHONOV were supported by NOAA (Grant No. NA19NES4320002 to CISESS-MD at the University of Maryland). The IAP/CAS data are available at http://www.ocean.iap.ac.cn/ and https://msdc.qdio.ac.cn. The NCEI/NOAA data are available at https://www.ncei.noaa.gov/products/climate-data-records/global-ocean-heat-content. This study has been conducted using also E.U. Copernicus Marine Service Information (https://marine.copernicus.eu/) for the Mediterranean OHC estimate. G. Li is supported by the Young Talent Support Project of Guangzhou Association for Science and Technology.
• In 2022, the global ocean was the hottest ever recorded by humans.
• The upper 2000 m salinity-contrast index, a quantification of the “salty gets saltier—fresh gets fresher” pattern, also reached its highest level on record in 2022.
• Global upper-ocean stratification continued its increasing trend in 2022 and was among the top seven on record.
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Cheng, L., Abraham, J., Trenberth, K.E. et al. Another Year of Record Heat for the Oceans. Adv. Atmos. Sci. (2023). https://doi.org/10.1007/s00376-023-2385-2
- ocean heat content
- global warming