The importance of ENSO phase during volcanic eruptions for detection and attribution
The importance of ENSO phase during volcanic eruptions for detection and attribution
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DOI：
10.1002/2016gl067935
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发表时间：
2016-03-28
影响因子：
5.2
通讯作者：
Froelicher, Thomas L.
中科院分区：
文献类型：
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作者：
Lehner, Flavio;Schurer, Andrew P.;Froelicher, Thomas L.
将最近火山爆发后观测到的全球尺度冷却与耦合模式相互比较项目5（CMIP 5）气候模式模拟的冷却进行比较，结果表明，这些模式高估了全球温度对火山爆发的反应程度。在这里，我们表明，这种高估可以解释为一个采样问题，因为自1951年以来所有的大爆发都与厄尔尼诺事件相吻合，导致全球范围的变暖，部分抵消了火山引起的冷却。根据观测到的厄尔尼诺-南方涛动（ENSO）阶段，在每次喷发的CMIP 5模式进行二次抽样，我们发现，模拟的全球温度响应火山强迫是与观测一致的。火山爆发对探测和归因方法提出了特别的挑战，因为火山爆发对地表的影响是短暂的，因此可能被厄尔尼诺/南方涛动混淆。我们的研究结果意味着，检测和归因研究必须仔细考虑由于内部气候变化的采样偏差。
Comparisons of the observed global-scale cooling following recent volcanic eruptions to that simulated by climate models from the Coupled Model Intercomparison Project 5 (CMIP5) indicate that the models overestimate the magnitude of the global temperature response to volcanic eruptions. Here we show that this overestimation can be explained as a sampling issue, arising because all large eruptions since 1951 coincided with El Nino events, which cause global-scale warming that partially counteracts the volcanically induced cooling. By subsampling the CMIP5 models according to the observed El Nino-Southern Oscillation (ENSO) phase during each eruption, we find that the simulated global temperature response to volcanic forcing is consistent with observations. Volcanic eruptions pose a particular challenge for the detection and attribution methodology, as their surface impacts are short-lived and hence can be confounded by ENSO. Our results imply that detection and attribution studies must carefully consider sampling biases due to internal climate variability.