The impact of a weakened AMOC on European heatwaves
In our changing climate we expect an increase in the frequency of heatwaves, which are extreme events that can have severe consequences for human health, ecosystems, and economies. In this study, we examine how the weakening of the atlantic meridional overturning circulation (AMOC) may influence the...
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| Language: | English |
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IOP Publishing
2025-01-01
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| Series: | Environmental Research Letters |
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| Online Access: | https://doi.org/10.1088/1748-9326/ada3e7 |
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| author | Virna L Meccia Claudia Simolo Katinka Bellomo Susanna Corti |
| author_facet | Virna L Meccia Claudia Simolo Katinka Bellomo Susanna Corti |
| author_sort | Virna L Meccia |
| collection | DOAJ |
| description | In our changing climate we expect an increase in the frequency of heatwaves, which are extreme events that can have severe consequences for human health, ecosystems, and economies. In this study, we examine how the weakening of the atlantic meridional overturning circulation (AMOC) may influence the occurrence of extreme warm events in Europe. Our analysis is based on a series of numerical experiments conducted using the EC-Earth3 climate model, which includes three ensembles of 20 Atmospheric Model Intercomparison Project-like members. The large ensemble size makes these simulations well-suited to studying rare extreme events. Our findings reveal that during boreal summer, the Northern hemisphere (NH) experiences overall mean cooling, most pronounced in the North Atlantic region. Therefore, the extreme warm events in Europe identified by using a fixed threshold tend to be less frequent. However, the cooling pattern reduces the meridional gradient of near-surface air temperature at high latitudes of the NH. As a result, the speed of the summer jet stream decreases, while the frequency of Ural atmospheric blocking events increases. Atmospheric blocking in summer is closely linked to heatwaves, primarily through subsidence warming and enhanced downward shortwave radiation under clear sky conditions. Consequently, the weakening of the AMOC leads to an increased frequency of heatwaves in Eastern Europe, the only region that presents this opposite trend. This study highlights the significant role that three-dimensional ocean circulation plays in shaping weather patterns, including extreme events such as heatwaves in Europe. These findings have important implications for future climate projections, as the AMOC is expected to weaken by the end of this century. Thus, as the Earth continues to warm, we may face an increased risk of heatwaves due to the combined effects of global warming and a weakening AMOC. |
| format | Article |
| id | doaj-art-c5a92f69827341b3b0774272d6943f83 |
| institution | Kabale University |
| issn | 1748-9326 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj-art-c5a92f69827341b3b0774272d6943f832025-01-10T11:21:57ZengIOP PublishingEnvironmental Research Letters1748-93262025-01-0120202400510.1088/1748-9326/ada3e7The impact of a weakened AMOC on European heatwavesVirna L Meccia0https://orcid.org/0000-0001-6905-2747Claudia Simolo1https://orcid.org/0000-0003-3634-1934Katinka Bellomo2https://orcid.org/0000-0001-7954-4390Susanna Corti3https://orcid.org/0000-0003-4456-6682National Research Council, Institute of Atmospheric Sciences and Climate , Bologna, ItalyNational Research Council, Institute of Atmospheric Sciences and Climate , Bologna, ItalyDepartment of Environment, Land and Infrastructure Engineering, Polytechnic University of Turin , Turin, Italy; National Research Council, Institute of Atmospheric Sciences and Climate , Turin, ItalyNational Research Council, Institute of Atmospheric Sciences and Climate , Bologna, ItalyIn our changing climate we expect an increase in the frequency of heatwaves, which are extreme events that can have severe consequences for human health, ecosystems, and economies. In this study, we examine how the weakening of the atlantic meridional overturning circulation (AMOC) may influence the occurrence of extreme warm events in Europe. Our analysis is based on a series of numerical experiments conducted using the EC-Earth3 climate model, which includes three ensembles of 20 Atmospheric Model Intercomparison Project-like members. The large ensemble size makes these simulations well-suited to studying rare extreme events. Our findings reveal that during boreal summer, the Northern hemisphere (NH) experiences overall mean cooling, most pronounced in the North Atlantic region. Therefore, the extreme warm events in Europe identified by using a fixed threshold tend to be less frequent. However, the cooling pattern reduces the meridional gradient of near-surface air temperature at high latitudes of the NH. As a result, the speed of the summer jet stream decreases, while the frequency of Ural atmospheric blocking events increases. Atmospheric blocking in summer is closely linked to heatwaves, primarily through subsidence warming and enhanced downward shortwave radiation under clear sky conditions. Consequently, the weakening of the AMOC leads to an increased frequency of heatwaves in Eastern Europe, the only region that presents this opposite trend. This study highlights the significant role that three-dimensional ocean circulation plays in shaping weather patterns, including extreme events such as heatwaves in Europe. These findings have important implications for future climate projections, as the AMOC is expected to weaken by the end of this century. Thus, as the Earth continues to warm, we may face an increased risk of heatwaves due to the combined effects of global warming and a weakening AMOC.https://doi.org/10.1088/1748-9326/ada3e7EC-Earth3AMOCheatwavesEuropeatmospheric blocking |
| spellingShingle | Virna L Meccia Claudia Simolo Katinka Bellomo Susanna Corti The impact of a weakened AMOC on European heatwaves Environmental Research Letters EC-Earth3 AMOC heatwaves Europe atmospheric blocking |
| title | The impact of a weakened AMOC on European heatwaves |
| title_full | The impact of a weakened AMOC on European heatwaves |
| title_fullStr | The impact of a weakened AMOC on European heatwaves |
| title_full_unstemmed | The impact of a weakened AMOC on European heatwaves |
| title_short | The impact of a weakened AMOC on European heatwaves |
| title_sort | impact of a weakened amoc on european heatwaves |
| topic | EC-Earth3 AMOC heatwaves Europe atmospheric blocking |
| url | https://doi.org/10.1088/1748-9326/ada3e7 |
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