Volcanic Cloud/Atmosphere Interactions: The First Week

火山爆发会产生复杂的气体、火山灰和气溶胶混合物云，这些云可以在地球大气中观察到几分钟到几年。它们的动力学及其演化的化学和物理过程鲜为人知，但它们构成了我们了解和减轻飞机危害、放射性尘埃对地方和区域健康的影响以及对全球气候的潜在影响的基础。由于火山学、地理和大气环境的组合在很大程度上是独一无二的，因此有必要将观测、建模和实验室工作结合起来进行面向过程的研究。在本提案中，我们计划整合过去10年火山云活动的几个关键例子的遥感研究。我们结合了火山喷发的数值模型，包括微物理过程、地面沉降物观测、云的直接采样、气象数据和基于实验室的火山灰/冰颗粒研究。重点放在火山云在持续数小时至约一周的时间内的演变。我们的努力的直接结果有望澄清与尘降物的机制和细灰的危害、二氧化硫向硫酸盐的转化以及冰在各种反应和过程中的作用有关的问题。这些结果对于了解火山爆发对当地和全球范围的环境影响非常重要，从牲畜中毒到呼吸系统疾病，从高温到气候变化，再到大规模物种灭绝。它们对减少对飞机的危害也很重要。我们集中研究了四次喷发，所有这些喷发我们都积累了大量的观测数据和经验，并且涵盖了一系列的火山和大气环境：(1)2000年2月26日的Hekla裂缝喷发，它代表了一个缺乏火山灰的例子，并且碰巧有重要的验证信息与之相关；(2) 1997年12月26日在蒙特塞拉特岛Soufriere Hills火山的喷发，其特征是与海洋的显著相互作用；(3) 1992年的三次亚地壳喷发具有异常广泛和完整的观测约束；(4) 1991年6月15日的皮纳图博火山喷发，这是上个世纪有记录的最大规模喷发。

RoseEAR-0106875Volcanic eruptions produce complex clouds of gas, ash and aerosol mixtures which can be observed in the Earth's atmosphere for minutes to years. Their dynamics, and the chemistry and physics of their evolution, are poorly known yet form the basis for our understanding and mitigation of aircraft hazards, local to regional health effects from fallout, and the potential for global climatic impact. Because the combination of volcanologic, geographic, and atmospheric settings is largely unique for each event, a process-oriented study combining observations, modeling, and laboratory efforts, is warranted.In this proposal, we plan to integrate remote sensing studies of several key examples of volcanic clouds from activity of the past 10 years. We combine numerical models of volcanic eruptions that include microphysical processes, ground-based observations of fallout materials, direct sampling of the clouds, meteorological data and lab-based studies of ash/ice particles. Emphasis is placed on the evolution of volcanic clouds during a period lasting hours to about one week. The direct results of our efforts are expected to clarify issues related to the mechanisms of fallout and hazards of fine ash, the conversion of SO2 to sulfate, and the role of ice in various reactions and processes. The results are important in understanding a wide range of local and global scale environmental effects of eruptions, ranging from livestock poisoning to respiratory disease to hypercanes to climate change to mass extinctions. They are also significant to the mitigation of hazards to aircraft. We focus on four eruptions, all for which we have amassed considerable observational data and experience, and which span a range of volcanic and atmospheric environments: (1) The February 26, 2000 Hekla fissure eruption, which represents an ash-poor example and which fortuitously has important validation information associated with it; (2) The December 26, 1997 eruption at Soufriere Hills Volcano, Montserrat, which is marked by significant interaction with the ocean; (3) The three 1992 subplinian Spurr eruptions which have unusually extensive and complete observational constraints; and (4) The climactic June 15, 1991 Pinatubo event, the largest well-documented eruption of the past century.