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.

亚速尔群岛高压是北大西洋上空的一个持续的大气高压脊，周围环绕着反气旋风，引导降雨天气系统并调节海洋水分向欧洲的输送。亚速尔高地的面积因此影响了整个西欧的降水，尤其是在冬季。在这里，我们使用观测和集合气候模型模拟来表明，在工业时代（自1850年以来） ，具有极大亚速尔群岛高压的冬季比工业化前时期更为常见，导致整个地中海西部异常干燥，包括伊比利亚半岛。对过去千年的模拟表明，亚速尔群岛高中的工业时代扩张在过去的千年中是前所未有的（因为ce 850），与葡萄牙的降水代理证据一致。亚速尔群岛 1850 年后出现高扩张，并在 20 世纪加强，这与人为驱动的变暖相一致。