Climatic response to high‐latitude volcanic eruptions
Climatic response to high‐latitude volcanic eruptions
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DOI：
10.1029/2004jd005487
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发表时间：
2005-07
影响因子：
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通讯作者：
L. Oman;A. Robock;G. Stenchikov;G. Schmidt;R. Ruedy
中科院分区：
文献类型：
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作者：
L. Oman;A. Robock;G. Stenchikov;G. Schmidt;R. Ruedy
[1]强烈的火山爆发会将大量的二氧化硫注入平流层下部，随着时间的推移，这些二氧化硫会转化为硫酸盐气溶胶，并有可能影响气候。热带火山爆发产生的气溶胶，如1991年皮纳图博火山爆发，遍布整个地球仪，而高纬度火山爆发产生的气溶胶通常留在它们注入的半球。这导致它们最大的辐射强迫是热带外的，气候响应应该不同于热带火山爆发。我们使用NASA戈达德空间研究所ModelE气候模式对1912年6月6日卡特迈火山爆发（58°N）的气候响应进行了20人集合模拟。我们还为3次Katmai（3x Katmai）喷发制作了一个额外的20个成员的集合，以了解喷发强度对辐射和动力学响应的影响。这些模拟的结果并没有像过去对热带火山爆发的模拟那样显示出积极的北极涛动响应，但我们确实发现了亚洲南部在北方冬季的显着降温。Katmai之后的第一个冬天和第三个Katmai之后的第二个冬天在平流层低层位势高度异常和海平面气压异常方面表现出很强的相似性，这是在两个案例具有相似的光学深度扰动时发生的。这些模拟表明，高纬度火山爆发的辐射影响远大于高纬度地区的动力影响。然而，在北半球夏季，北方半球陆地的强烈降温导致亚洲季风环流减少，云量显着减少高达10%，印度北方地区变暖。因此，高纬度爆发的主要动力影响是在亚洲的夏季。
[1] Strong volcanic eruptions can inject large amounts of SO2 into the lower stratosphere, which over time, are converted into sulfate aerosols and have the potential to impact climate. Aerosols from tropical volcanic eruptions like the 1991 Mount Pinatubo eruption spread over the entire globe, whereas high-latitude eruptions typically have aerosols which remain in the hemisphere in which they where injected. This causes their largest radiative forcing to be extratropical, and the climate response should be different from that of tropical eruptions. We conducted a 20-member ensemble simulation of the climate response to the Katmai eruption (58°N) of 6 June 1912 using the NASA Goddard Institute for Space Studies ModelE climate model. We also produced an additional 20-member ensemble for a 3 times Katmai (3x Katmai) eruption to see the impact the strength of the eruption has on the radiative as well as the dynamical responses. The results of these simulations do not show a positive Arctic Oscillation response like past simulations of tropical volcanic eruptions, but we did find significant cooling over southern Asia during the boreal winter. The first winter following Katmai and the second winter following 3x Katmai showed strong similarities in lower stratospheric geopotential height anomalies and sea level pressure anomalies, which occurred when the two cases had similar optical depth perturbations. These simulations show that the radiative impact of a high-latitude volcanic eruption was much larger than the dynamical impact at high latitudes. In the boreal summer, however, strong cooling over the Northern Hemisphere landmasses caused a decrease in the Asian monsoon circulation with significant decreases of up to 10% in cloud cover and warming over northern India. Thus the main dynamical impact of high-latitude eruptions is in the summer over Asia.