Assessing the impact of very large volcanic eruptions on the risk of extreme climate events
Assessing the impact of very large volcanic eruptions on the risk of extreme climate events
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评估超大型火山喷发对极端气候事件风险的影响
DOI：
10.1088/2752-5295/acee9f
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发表时间：
2023-08
期刊：
影响因子：
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通讯作者：
N. Freychet;A. Schurer;A. Ballinger;Laura Suarez‐Gutierrez;C. Timmreck
中科院分区：
文献类型：
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作者：
N. Freychet;A. Schurer;A. Ballinger;Laura Suarez‐Gutierrez;C. Timmreck
大规模火山爆发对气候有重大影响，导致全球变冷和水文循环的重大变化。虽然大多数研究都集中在平均气候的变化，在这里，我们使用一个大的合奏，以评估极端气候的影响，三年后的热带和热带外火山爆发不同的硫排放强度。我们专注于一个非常大的火山爆发的影响，注入40 Tg的硫到平流层，这可能会发生大约两次千年。我们的研究结果表明，火山爆发将对地球仪的大片地区产生深远影响，导致在正常情况下每世纪发生一次的极其罕见的干旱事件变得非常有可能。西非、南亚和东亚以及海洋大陆等几个地区受到的影响尤其严重，预计气候变化将远远超出正常范围，最高可达5个标准差。这些结果具有重要的后果，因为它们表明，在大规模火山爆发后，预计多个粮仓地区将发生严重干旱。在同一地区，强降雨的风险往往会减少，但减少的数量，热浪变得非常罕见，然而，极端冬季寒潮的机会不会增加相应的数量，因为北方的大部分地区显示冬季变暖。我们的研究结果表明，火山爆发的位置是至关重要的极端的变化，整体变化较大的北方半球的火山爆发比热带和南半球的火山爆发，虽然有一个区域的依赖性。模拟的不同爆发相似的强迫分布，但不同的大小是一致的线性关系，但较小的爆发的内部变率往往成为主导和极端气候的影响较少检测。
Very large volcanic eruptions have substantial impacts on the climate, causing global cooling and major changes to the hydrological cycle. While most studies have focused on changes to mean climate, here we use a large ensemble to assess the impact on extreme climate for three years following tropical and extratropical eruptions of different sulfur emission strength. We focus on the impact of an extremely large eruption, injecting 40 Tg sulfur into the stratosphere, which could be expected to occur approximately twice a millennium. Our findings show that the eruption would have a profound effect on large areas of the globe, resulting in extremely rare drought events that under normal circumstances would occur once every century becoming very likely. Several regions such as West Africa, South and East Asia and the Maritime continent are particularly affected with the expected climate shifting well outside the usual range, by up to five standard deviations. These results have important consequences as they indicate that a severe drought in multiple breadbasket regions should be expected following a large eruption. The risk of heavy rainfall tends to decrease over the same regions but by a reduced amount, heatwaves become extremely rare, however the chance of extreme Winter cold surges do not increase by a corresponding amount, since widespread parts of the Northern Hemisphere display a winter warming. Our results show that the location of the eruption is crucial for the change in extremes, with overall changes larger for a Northern Hemisphere eruption than a tropical and Southern Hemisphere eruption, although there is a regional dependency. Simulations of different eruptions with similar forcing distributions but with different sizes are consistent with a linear relationship, however for smaller eruptions the internal variability tends to become dominant and the effect on extreme climate less detectable.