The team of researcher Du Yan from the South China Sea Institute of Oceanology, Chinese Academy of Sciences, together with Ming Feng, Principal Research Scientist and Alistair J. Hobday, Senior Principal Research Scientist of the Commonwealth Scientific and Industrial Research Organisation of Australia, revealed the diversity of the vertical structure of global marine heat waves and their spatiotemporal characteristics on the role of ocean heat storage and heat redistribution in the context of global warming. Recently, the results were published in Nature Communications.
Figure A shows extreme marine heatwave events, and b-e shows the vertical structure of different types of marine heatwaves. Courtesy of the research team
Zhang Ying, first author of the paper and an associate researcher at the South China Sea Institute of Oceanology of the Chinese Academy of Sciences, said that marine heatwaves are abnormally warm water events that occur in the ocean. Previous studies have shown that the warm anomalies of marine heatwaves are not confined to the surface of the ocean and can also reach the deep ocean, and in addition, the driving mechanisms and responses of marine organisms at different depths of marine heatwaves are significantly different. However, the vertical structure and depth of impact of global marine heatwaves are currently unknown.
Based on satellite SST and subsurface temperature profile data observed by Argo, this study defined four main types of marine heatwaves with different vertical structures: shallow, subsurface inverse, subsurface strengthened and deep ocean heatwaves, and analyzed the temporal and spatial characteristics of these four types of ocean heatwaves and related dynamic mechanisms.
The results show that the spatial distribution of marine heatwaves with different vertical structures is significantly different, and the subsurface reverse and subsurface enhanced marine heatwaves account for a relatively high proportion in low-latitude seas, while shallow and deep ocean heatwaves are more common in middle and high latitudes. Ocean multi-scale dynamic processes play an important role in the formation of the vertical structure of ocean heat waves, which also reflects the important influence of ocean dynamic processes on ocean heat redistribution. The impact depth of shallow and subsurface inverse marine heat waves is shallow, while the subsurface enhanced and deep ocean heat waves have deep impact depths, and their spatial distribution is closely related to the thermodynamic background of the ocean.
“Over the past 20 years, these four types of marine heatwaves have shown a significant increase in the number of these four types of marine heatwaves due to the continuous warming of the oceans, accompanied by a deepening of the impact depth. Du Yan, the corresponding author of the paper, said that the results of this study are helpful for the systematic understanding of the spatiotemporal characteristics and formation mechanism of marine extreme events, and provide an important scientific basis for the construction of a three-dimensional monitoring system and forecasting platform for marine disasters. (Source: China Science News, Zhu Hanbin, Fu Tian)
Related Paper Information:https://www.nature.com/articles/s41467-023-42219-0