Quantitative Study of SO2 and Reactive Halogen Chemistry in Volcanic Plumes by Imaging with a Novel Fabry-Pérot Camera Technique

通过新型法布里-珀罗相机技术成像定量研究火山羽流中的 SO2 和活性卤素化学

• 批准号: 399112922
• 负责人: Professor Dr. Ulrich Platt
• 金额: --
• 依托单位: Institut für Umweltphysik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/399112922?language=en
• 关键词: Quantitative; Study; SO2; Reactive; Halogen

Imaging two dimensional (2D) distributions of volcanic gases with high time resolution (i.e. at time scales of seconds), allows to study processes which are not accessible to traditional scanning methods. These include: (1) to directly visualize transport and turbulent mixing processes at their intrinsic time scales and (2) to study chemical transformation (e.g. the formation ob BrO) in real time. Moreover, (3) spatial gradients of trace gases (e.g. of BrO and OClO) and their evolution in the plume can be analyzed, which allows to infer details of chemical processes.At present 2D imaging is possible only for volcanic SO2 by using devices which have become known as “SO2 cameras”. They rely on relating images acquired in two narrow wavelengths regions (defined by interference filters). While the introduction of SO2 cameras in recent years marked are a major breakthrough in volcanic gas research they are not applicable to other volcanic gases and also suffer from cross interferences, e.g. to volcanic aerosol.Here we propose the development and application of a novel, Fabry-Perot Interferometer (FPI) – based imaging technique capable of recording the spatial distributions of several important volcanic gases at high time resolution and virtually without interference. We already demonstrated its practical applicability for SO2 and showed that the technique has the sensitivity and specificity to also image BrO and OClO in volcanic plumes. Within the proposed project we intent to build practical devices for the imaging of these three gases and to apply the instruments to studies of the evolution of halogen radical concentrations. This will be done for quiescent degassing as well as for explosive plumes. The intended studies are not possible with any other known technique. In addition, the work proposed here will form the basis to apply the FPI technique to a range of further atmospheric gases (e.g. IO, NO2, CH2O) in the future.

成像二维（2D）分布的火山气体与高时间分辨率（即在秒的时间尺度），允许研究的过程是无法访问传统的扫描方法。其中包括：（1）在其固有的时间尺度上直接可视化传输和湍流混合过程;（2）在真实的时间内研究化学转化（例如BrO的形成）。此外，（3）可以分析痕量气体（例如BrO和OClO）的空间梯度及其在羽流中的演化，这允许推断化学过程的细节。它们依赖于在两个窄波长区域（由干涉滤光片定义）中获取的相关图像。近年来，SO_2相机的出现标志着火山气体研究的一个重大突破，但它不适用于其他火山气体，而且还存在交叉干扰，如火山气溶胶。法布里-珀罗干涉仪（FPI）-基于成像技术，能够以高时间分辨率且几乎不受干扰地记录几种重要火山气体的空间分布。我们已经证明了其对SO2的实用性，并表明该技术具有灵敏度和特异性，也可以在火山羽流中成像BrO和OClO。在拟议的项目中，我们打算建立这三种气体的成像实用设备，并将仪器应用于卤素自由基浓度演变的研究。这将用于静态脱气以及爆炸性羽流。使用任何其他已知技术无法进行预期研究。此外，这里提出的工作将形成基础，应用FPI技术的范围内进一步的大气气体（如IO，NO2，CH 2 O）在未来。