Stratospheric loading of sulfur from explosive volcanic eruptions
Stratospheric loading of sulfur from explosive volcanic eruptions
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DOI：
10.1086/515972
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发表时间：
1997-11-01
影响因子：
1.8
通讯作者：
Krueger, AJ
中科院分区：
文献类型：
--
作者：
Bluth, GJS;Rose, WI;Krueger, AJ
本文试图通过比较1979年至1994年期间平流层潜在火山气溶胶产生和去除的箱形模式与平流层气溶胶光学深度，来衡量我们对火山/大气相互作用的理解。模型结果和观测数据在埃尔奇琼和皮纳图博这两个最大的火山喷发的震级和清除速率上都很一致。然而，平流层光学深度的峰值发生在火山爆发前后的9个月左右，比模型预测的时间长4倍，这是由实际二氧化硫测量结果驱动的。对于较小的喷发，观测到的平流层扰动通常比模拟的要小得多，观测到的气溶胶去除速率比预期的要慢得多。这些结果表明，在火山爆发后的几个月里，我们对火山-大气反应的认识存在一些局限性。此外，很明显，较小的火山喷发所排放的大部分硫都没有对平流层产生任何影响。这表明了一个阈值，即不高于对流层顶（从赤道到极地纬度高度下降）的喷发柱受到高效的sell-removal过程的影响。在我们的研究期间，每座低纬度火山的喷发速率需要达到50,000 m(3)/s（致密岩石当量）的量级，才能对平流层光学深度产生显著的全球扰动，即大于0.001。然而，在高纬度地区（大约40度），这种水平的平流层撞击是由喷发率小一个数量级产生的。
This paper is an attempt to measure our understanding of volcano/atmosphere interactions by comparing a box model of potential volcanogenic aerosol production and removal in the stratosphere with the stratospheric aerosol optical depth over the period of 1979 to 1994. Model results and observed data are in good agreement both in magnitude and removal rates for the two largest eruptions, El Chichon and Pinatubo. However, the peak of stratospheric optical depth occurs about nine months alter the eruptions, four times longer than the model prediction, which is driven by actual SO2 measurements. For smaller eruptions, the observed stratospheric perturbation is typically much less pronounced than modeled, and the observed aerosol removal rates much slower than expected. These results indicate several limitations in our knowledge of the volcano-atmosphere reactions in the months following an eruption. Further, it is evident that much of the emitted sulfur from smaller eruptions fails to produce any stratospheric impact. This suggests a threshold whereby eruption columns that do not rise much higher than the tropopause (which decreases in height from equatorial to polar latitudes) are subject to highly efficient sell-removal processes. Per low latitude volcanoes during our period of study, eruption rates on the order of 50,000 m(3)/s (dense rock equivalent) were needed to produce a significant global perturbation in stratospheric optical depth, i.e., greater-than 0.001. However, at high (>40 degrees) latitudes, this level of stratospheric impact was produced by eruption rates an order of magnitude smaller.