New record for ocean warming in 2022

Ocean warming set a new record last year, making it the seventh consecutive year. A consequence that is also accompanied by a rise in stratification and a variation in the salinity of the water.

The study "Another year of record heat for the oceans," signed by a global team of 24 researchers from 16 institutes, including Franco Reseghetti of the National Agency for new Technologies, Energy, and sustainable economic development (Enea) and Simona Simoncelli of the National Institute of Geophysics and Volcanology (Ingv), is titled "Another year of record heat for the oceans.". The Macmap project, funded by Ingv and carried out in partnership with Grandi Navi Veloci, aims to study climate change through seasonal monitoring of the temperature of the Ligurian and Tyrrhenian seas along the genoa-palermo section and to analyze reanalysis data and climate models ranging from 1950 to 2050. "Ingv and Enea," explained Simoncelli, "are already collaborating within the Macmap project.".

According to the study that examines data from the National Centers for Environmental Information (NCEI) of the National Oceanic and Atmospheric Administration and the Institute of Atmospheric Physics (IAP) of the Chinese Academy of Sciences, from the 1950s to the present, both datasets "show a record value of heat accumulated in the first 2,000 meters of the ocean depth in 2022," says Tim Boyer of the Ncei. Approximately 10 Zetta Joules (ZJ) or 100 times the world's electricity production in 2021, 325 times that of China, and just under 9,700 times that of Italy's electricity production increased the heat content of the ocean between the surface and 2,000 meters deep last year compared to the previous year.

Professor Lijing Cheng, the first author of the study and a member of the Chinese Academy of Sciences, stated that "ocean warming continues and manifests itself both with new records for the thermal content of the waters and with new extreme values for salinity. Areas with harder water get even less salty, and areas that are already salty get even saltier.

"Although not consistently across the globe, rising salinity and ocean stratification can change how heat, carbon, and oxygen are exchanged between the ocean and the atmosphere. which, as a result, may result in deoxygenation within the water column, which is extremely concerning for both humans and terrestrial ecosystems in addition to marine life and ecosystems.

As a result, important fish species are forced to move, which poses a serious threat to the economies of communities that depend on fishing and contributes to the decline in marine biodiversity. Additionally, it plays a role in meteorological anomalies like the recurrent heat waves that characterized the weather in Western Europe last year, setting new records for temperature and precipitation levels.

We are able to maintain a high level of attention on global warming and its effects on the ocean, which in turn have an impact on man and the closely related economic activities, thanks to our collaboration with this international team, particularly with Professor Cheng, said Reseghetti. In this situation, the Mediterranean's heat has not increased despite being confirmed as the study's fastest warming basin.

In fact, even though Iap estimates indicate that the heat content in 2022 was the same as that in 2021, data from the reanalysis model provided by the European marine service Copernicus indicate that there was a drop from the year before. The Mediterranean's heat has not increased, despite the fact that it is the basin that is warming the fastest among those examined in the study.