A vulnerability alert study of coastal areas in the face of the current climatic emergency due to the rise in sea level, which will affect the average characteristics of the waves, especially in certain regions such as the coasts of the southwest, the east of ocean basins and polar areaswhich could affect coastal processes in the long term.
The work, which is entitled “Dissemination for Transitional Wave Climate Regions on Continental and Polar Coasts in a Warming World“, has been published in the magazine “Nature Climate Change”.
In this scientific article, prepared by various researchers, including Itxaso Odériz, from the Institute of Environmental Hydraulics of the University of Cantabria (UC), in the north of Spain, the high sensitivity of coastal areas to meteorological events and climatological alterations on multiple time scales (from storms to variations that last more than years or decades) is pointed out.
In addition, as reported by the university in a statement, it also highlights that climate change affects the average wave characteristics, modifying the frequency of occurrence of global wave climates (from the east, south and west).
The coastal areas where the waves change frequencyand inherently of direction and energy, are called wave climatic transition regions, which the study identifies in the southwestern coasts, the east of the ocean basins and in the polar regions.
In the studies carried out, it is observed that the global wave climate consists of three main climates, driven by atmospheric circulation that affect coastlines around the world: south swells (generated by subpolar and subtropical winds), easterly swells (generated by trade and polar winds) and westerly swells (generated in the extra-tropical and monsoonal region).
This classification is based on an analysis of the spatial and temporal variations of these wave climates in global warming scenarios proposed by the Intergovernmental Group of Experts on Climate change at the end of the 21st century.
The scientific team of the study has detected that the great increase in wave energy is concentrated in high latitudes of the Southern Oceaninduced by a poleward intensification of the extratropical atmospheric circulation.
The results obtained showed that the southern swell climatic transition regions (coasts with an increase in the frequency of southern swells) are located in the eastern Pacific, the southeastern Atlantic and the eastern Indian Ocean.
The most intense waves that have been affecting the Pacific coast of the American continent during the last decade belong to this wave climate.
According to the study, easterly swell weather is expected to be more prevalent along the southeastern coast of Africa and the northwest and southwestern Atlantic, and westerly swell weather is expected to be more prevalent in the northwestern Atlantic. Pacific Ocean and New Zealand due to the poleward shift of extra-tropical winds.
In addition, in some coastal regions, the difference in the frequency of occurrence of wave climates between seasons will be more noticeable, altering the existing natural balance in coastal environments.
Regarding the polar regions and the importance of melting ice in wave generation, areas of these coasts were identified that will be exposed to wave climates to which they were not exposed in the last century, because sea melting gives rise to new open ocean regions where the probability of storm development increases, which can lead to further erosion of permafrost and ice in the polar regions.
In addition, the waves in new regions open to the sea can allow the transport of species and pollution.
The results of the study are more critical for the Arctic Ocean, however it indicates that changes in the waves in the Antarctic Ocean can affect the continental coasts, due to the propagation capacity of these waves that travel from high to low latitudes.
Finally, within the climatic regions of wave transition, the research indicates that the polar regions are particularly complex because the melting can open new wave generation zones, these being critical for the future of the coasts.
Currently, as the press release points out, the approach to this issue is still under development, highlighting the study of these as potential risk areas where changes in the variability of wave climates can alter long-term coastal processes.
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