Twentieth-century Azores High expansion unprecedented in the past 1,200 years
Cresswell-Clay, N.; Ummenhofer, C.C.; Thatcher, D.L.; Wanamaker, A.D.; Denniston, R.F.; Asmerom, Y.; Polyak, V.J. (2022). Twentieth-century Azores High expansion unprecedented in the past 1,200 years. Nature Geoscience 15(7): 548-553. https://dx.doi.org/10.1038/s41561-022-00971-w
In: Nature Geoscience. Nature Publishing Group: London. ISSN 1752-0894; e-ISSN 1752-0908, more
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| Authors | | Top |
- Cresswell-Clay, N.
- Ummenhofer, C.C.
- Thatcher, D.L.
- Wanamaker, A.D.
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- Denniston, R.F.
- Asmerom, Y.
- Polyak, V.J.
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| Abstract |
The Azores High is a persistent atmospheric high-pressure ridge over the North Atlantic surrounded by anticyclonic winds that steer rain-bearing weather systems and modulate the oceanic moisture transport to Europe. The areal extent of the Azores High thereby affects precipitation across western Europe, especially during winter. Here we use observations and ensemble climate model simulations to show that winters with an extremely large Azores High are significantly more common in the industrial era (since ce 1850) than in pre-industrial times, resulting in anomalously dry conditions across the western Mediterranean, including the Iberian Peninsula. Simulations of the past millennium indicate that the industrial-era expansion of the Azores High is unprecedented throughout the past millennium (since ce 850), consistent with precipitation proxy evidence from Portugal. Azores High expansion emerges after ce 1850 and strengthens into the twentieth century, consistent with anthropogenically driven warming. |
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