The Influence of Recent Volcanic Eruptions on Stratospheric Ozone Recovery: A Data Analysis and Modeling Study Including Estimated Uncertainties

这个项目的重点是调查最近的小型火山爆发对平流层臭氧的影响。人们曾经认为，只有非常剧烈的火山爆发才会影响平流层中小颗粒的含量。然而，最近的观测表明，自2005年以来，由于一系列较小的火山喷发，平流层气溶胶层发生了实质性的火山增强。这些喷发发生的时候，臭氧层的恢复应该越来越明显。火山气溶胶对过去臭氧的变化产生了重大的、有充分证据的影响，但迄今为止，在确定恢复情况的努力中，只得到定性而不是定量的关注。这项研究将促进对臭氧对平流层气溶胶变化敏感性的认识，并改善估算臭氧恢复不确定性的基础。将比较2000年以来来自卫星和地面方法的广泛气溶胶数据，并将其用于改进最近平流层气溶胶变化的特征和不同测量方法之间的不确定性。将使用的数据包括CCMI（化学-气候模式倡议）项目气溶胶数据，以及来自分布式站点、卫星观测和怀俄明大学气球探空仪的激光雷达数据。特定动力学全大气群落气候模式（SD-WACCM）将用于进行敏感性试验，以研究动力学速率常数、本底气溶胶水平和水蒸气变率的不确定性如何影响火山表面积变化如何影响平流层最下层（包括靠近对流层顶的区域）的臭氧消耗。自1991年以来观测到的最大平流层气溶胶负担发生在2011年纳布罗火山喷发之后。当时报告的平流层气溶胶柱丰度在某些地点和时间达到了Pinatubo之后最大值的30-50%。迄今为止，尚未评估这些扰动对中纬度和全球臭氧损失和恢复的影响。确保化学回收的特征能够被充分理解，被广泛认为是全面评估科学理解及其在这一高度可见问题的科学-政策界面中的作用的必要步骤。

This project focuses on an investigation of the effects of recent small volcanic eruptions on stratospheric ozone. It was once believed that only very explosive volcanic eruptions could affect the content of small particles in the stratospheric. However recent observations suggest that substantial volcanic enhancements of the stratospheric aerosol layer have occurred due to a series of smaller eruptions since about 2005. These eruptions have occurred just at the time when ozone recovery should be becoming more and more discernible. Volcanic aerosols have had major, well-documented effects on past changes in ozone, but have received only qualitative rather than quantitative attention in efforts to identify recovery to date. This research will advance the understanding of the sensitivity of ozone to changes in stratospheric aerosols and improve the basis for estimating uncertainty in ozone recovery. A broad range of aerosol data since 2000 from satellite- and ground-based methods will be compared and used to improve the characterization of recent stratospheric aerosol changes and the uncertainties across different measurements. Data to be used include the CCMI (Chemistry-Climate Model Initiative) project aerosol data together with lidar data from distributed stations, satellite observations, and the University of Wyoming balloonsondes. The Specified Dynamics Whole Atmosphere Community Climate Model (SD-WACCM) will be used in the conduct of sensitivity tests to examine how uncertainties in kinetic rate constants, in background aerosol levels, and in variability of water vapor influence how volcanic surface area changes affect ozone depletion in the lowermost stratosphere, including the region close to the tropopause.The largest stratospheric aerosol burden since 1991 was observed in 2011 following the Nabro eruption. At that time, reported column abundances of stratospheric aerosol at some locations and times reached as high as 30-50% of the maximum values obtained after Pinatubo. To date, the implications of these perturbations for mid-latitude and global ozone loss and recovery have not been assessed. Ensuring that the signature of chemical recovery can be fully understood is broadly acknowledged as a needed step in the comprehensive evaluation of scientific understanding and its role in the science-policy interface on this highly visible issue.