Large impacts, past and future, of ozone‐depleting substances on Brewer‐Dobson circulation trends: a multimodel assessment
Substantial increases in the atmospheric concentration of well-mixed greenhouse gases (notably CO_(2)), such as those projected to occur by the end of the 21st century under large radiative forcing scenarios, have long been known to cause an acceleration of the Brewer-Dobson circulation (BDC) in cli...
| Autores: | , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2019 |
| País: | España |
| Institución: | Universidad Complutense de Madrid (UCM) |
| Repositorio: | Docta Complutense |
| Idioma: | inglés |
| OAI Identifier: | oai:docta.ucm.es:20.500.14352/108238 |
| Acceso en línea: | https://hdl.handle.net/20.500.14352/108238 |
| Access Level: | acceso abierto |
| Palabra clave: | 551.51 Brewer-Dobson circulation Ozone-depleting substances Age of air Stratospheric circulation Chemistry-climate models Física atmosférica 2501 Ciencias de la Atmósfera |
| Sumario: | Substantial increases in the atmospheric concentration of well-mixed greenhouse gases (notably CO_(2)), such as those projected to occur by the end of the 21st century under large radiative forcing scenarios, have long been known to cause an acceleration of the Brewer-Dobson circulation (BDC) in climate models. More recently, however, several single-model studies have proposed that ozone-depleting substances might also be important drivers of BDC trends. As these studies were conducted with different forcings over different periods, it is difficult to combine them to obtain a robust quantitative picture of the relative importance of ozone-depleting substances as drivers of BDC trends. To this end, we here analyze—over identical past and future periods—the output from 20 similarly forced models, gathered from two recent chemistry-climate modeling intercomparison projects. Our multimodel analysis reveals that ozone-depleting substances are responsible for more than half of the modeled BDC trends in the two decades 1980–2000.We also find that, as a consequence of the Montreal Protocol, decreasing concentrations of ozone-depleting substances in coming decades will strongly decelerate the BDC until the year 2080, reducing the age-of-air trends by more than half, and will thus substantially mitigate the impact of increasing CO_(2). As ozone-depleting substances impact BDC trends, primarily, via the depletion/recovery of stratospheric ozone over the South Pole, they impart seasonal and hemispheric asymmetries to the trends which may offer opportunities for detection in coming decades. |
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