Arctic sea ice response to the eruptions of Agung, El Chichon, and Pinatubo
Arctic sea ice response to the eruptions of Agung, El Chichon, and Pinatubo
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DOI：
10.1002/2017jd027038
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发表时间：
2017-08-16
影响因子：
4.4
通讯作者：
Fyfe, J. C.
中科院分区：
文献类型：
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作者：
Gagne, M. -E.;Kirchmeier-Young, M. C.;Fyfe, J. C.
利用气候模式模拟的大型初始条件集合，我们研究了1960年至2005年期间火山活动对北极海冰覆盖的影响，这一时期包括三次非常大的热带火山喷发。模拟中仅考虑自然（火山和太阳）强迫的整体平均减少了由于内部变率造成的噪声，从而显示在阿贡火山（1963年）、奇川火山（1982年）和皮纳图博火山（1991年）每次喷发之后，北极海洋面积增加了十年（最多50万平方公里）。在对自然的和所有已知的人为强迫的大型模拟集合进行平均时，可以看到类似的影响。研究表明，海冰覆盖的火山响应对喷发前温度敏感，喷发前较暖的条件与大于平均水平的响应相关。最后，使用第二代加拿大地球系统模型（CanESM2）进行检测和归因分析，没有发现观测结果中有显著的响应，而由于回归系数与统一一致，观测结果与CanESM2之间没有不一致的证据。类似的探测和归因分析利用CMIP5模式平均模拟中更强的火山响应，确实在四个观测海冰范围数据集中发现了可探测的自然强迫响应。
Using a large initial condition ensemble of climate model simulations, we examine the impact of volcanic activity on Arctic sea ice cover from 1960 to 2005, a period that includes three very large tropical eruptions. Ensemble averaging across simulations with natural (volcanic and solar) forcings alone reduces noise due to internal variability to show a decade of increased Arctic sea extent (of up to half a million square kilometers) following each of the Mount Agung (1963), Mount El Chichon (1982), and Mount Pinatubo (1991) eruptions. A similar impact is seen when averaging over a large ensemble of simulations with natural and all-known anthropogenic forcings. We show that the volcanic response in sea ice cover is sensitive to preeruption temperature, with warmer conditions before an eruption being associated with a larger than average response. Finally, a detection and attribution analysis using second-generation Canadian Earth System Model (CanESM2) did not identify a significant response in the observations, while finding no evidence of inconsistency between observations and CanESM2 since regression coefficients were consistent with unity. A similar detection and attribution analysis using the somewhat stronger volcanic response from the simulations in the average of the CMIP5 models did identify a detectable natural forcing response in four observational sea ice extent data sets.