Catastrophic loss of stratospheric ozone in dense volcanic clouds
Catastrophic loss of stratospheric ozone in dense volcanic clouds
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浓密火山云中平流层臭氧的灾难性损失
DOI：
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发表时间：
1992
期刊：
影响因子：
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通讯作者：
M. Prather
中科院分区：
文献类型：
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作者：
M. Prather
据预测，在中纬度和热带平流层中，如果存在浓度非常高的硫酸盐气溶胶，臭氧将发生迅速的局部损失。火山喷发可以增加硫酸的有效表面积，使得涉及ClONO 2和其次是N2 O 5的非均相反应能够相对于气相化学抑制NOx丰度超过10倍。当NOx水平下降到阈值以下时，例如，0.6在中纬度地区，24公里处的臭氧浓度为ppb，氯催化的O3损失的速度与南极臭氧洞形成期间的速度相当，每天超过50 ppb。如果这种损失发生在皮纳图博火山喷发后，在热带和中纬度地区的火山扰动最严重的地区，该模型预测，它们主要是由NOx的抑制低于这些临界水平。自El Chichon以来，平流层氯的增加使皮纳图博山在造成快速O3损失方面的效力增加了两倍多。与火山爆发相关的全球总损失在硫酸盐表面积的量上近似线性，但关键取决于CIONO 2-硫酸盐反应的速率。
Rapid, localized loss of ozone is predicted to occur in the mid-latitude and tropical stratosphere in the presence of very large concentrations of sulfate aerosols. Volcanic eruptions can increase the effective surface area of sulfuric acid so that heterogeneous reactions involving ClONO2, and secondarily N2O5, are able to suppress NOx abundances by more than a factor of 10 relative to gas phase chemistry. When NOx levels fall below a threshold, e.g., 0.6 ppb at 24 km in mid-latitudes, the chlorine-catalyzed loss of O3 proceeds at rates comparable to those during the formation of the Antarctic ozone hole, more than 50 ppb per day. If such losses occurred following the eruption of Mount Pinatubo in the most volcanically perturbed regions over the tropics and mid-latitudes, this model predicts that they are driven primarily by the suppression Of NOx below these critical levels. The increase in stratospheric chlorine since El Chichon has made Mount Pinatubo more than twice as effective in causing rapid O3 loss. Overall global losses associated with a volcanic eruption are approximately linear in the amount of sulfate surface area, but depend critically on the rate of the CIONO2-sulfate reaction.