Tropical Volcanic Eruptions and Low Frequency Indo‐Pacific Variability Drive Extreme Indian Ocean Dipole Events
Tropical Volcanic Eruptions and Low Frequency Indo‐Pacific Variability Drive Extreme Indian Ocean Dipole Events
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DOI：
10.1029/2023gl103991
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发表时间：
2023-10
影响因子：
5.2
通讯作者：
Benjamin H. Tiger;C. Ummenhofer
中科院分区：
文献类型：
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作者：
Benjamin H. Tiger;C. Ummenhofer
火山喷发会对气候产生重大影响，并可作为有用的自然实验，以便更好地理解突发的、外部强迫的气候变化的影响。在此，我们研究了印度洋偶极子（IOD）对过去千年中最大的热带火山喷发的响应。喷发后的合成数据显示，在喷发当年出现强烈的负IOD，次年出现正IOD。IOD和厄尔尼诺 - 南方涛动（ENSO）呈现出一种长期的阻尼振荡响应，可能需要长达8年才能恢复到喷发前的基准状态。此外，喷发时的太平洋年代际振荡（IPO）相位控制着IOD对强烈喷发的响应，负（正）IPO相位通过调节东印度洋温跃层深度的背景状态，有利于产生更负（正）的IOD值。这些结果对于低概率、高影响情景下的气候风险具有重要意义，特别是对于没有为IOD和ENSO极端情况做好准备的脆弱社区。
Volcanic eruptions can have significant climate impacts and serve as useful natural experiments for better understanding the effects of abrupt, externally forced climate change. Here, we investigate the Indian Ocean Dipole's (IOD) response to the largest tropical volcanic eruptions of the last millennium. Post‐eruption composites show a strong negative IOD developing in the eruption year, and a positive IOD the following year. The IOD and El Niño‐Southern Oscillation (ENSO) show a long‐term damped oscillatory response that can take up to 8 years to return to pre‐eruptive baselines. Moreover, the Interdecadal Pacific Oscillation (IPO) phase at the time of eruption controls the IOD response to intense eruptions, with negative (positive) IPO phasing favoring more negative (positive) IOD values via modulation of the background state of the eastern Indian Ocean thermocline depth. These results have important implications for climate risk in low‐likelihood, high‐impact scenarios, particularly in vulnerable communities unprepared for IOD and ENSO extremes.