Dense Gas Dispersion and Modelling at Fagradalsfjall, Iceland

冰岛 Fagradalsfjall 的稠密气体扩散和建模

• 批准号: NE/W004852/1
• 负责人: Ralph Burton
• 金额: $ 6.43万
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FW004852%2F1
• 关键词: Dense; Gas; Dispersion; Modelling; Fagradalsfjall

The ongoing eruption at Fagradalsfjall in Iceland presents an outstanding and rare opportunity to observe and model the behaviour of dense volcanic gases. Sulphur Dioxide (SO2) is the principal emission from lava-rich eruptions such as at Fagradalsfjall. With more than double the molecular weight of air, this is prone to exhibiting dense gas dispersion characteristics such as settling, with the potential to significantly affect the dispersion over scales of hundreds of kilometers. This can lead to enhanced concentrations at low levels with consequences for air quality and human health. This project aims to (a) collect a surface air quality and meteorological dataset and (b) produce a modelling framework capable of simulating dense gas and validate it against (a). Such a framework does not exist at present. This is a significant, time-limited and accessible eruption event which, if responded to now, can lead to major advances in both scientific understandings and in the management of future, possibly larger, eruptions from which there is a serious gas hazard. (A) We will enhance existing air quality observations in the vicinity of Fagradalsfjall, creating a network to provide a comprehensive assessment of dense volcanic gas dispersion on a scale of 50-100 km. This unique dataset will provide the first independent verification for a full meteorological prediction model with dense gas capability coupled with surface heating (see below).(B) Recent model development work has demonstrated effective volcanic gas dispersion predictions using an adapted version of the NCAR Weather Research and Forecasting (WRF) model. This system was used to successfully interpret aircraft measurements of CO2 dispersion from the (subglacial) Katla volcano in Iceland and to explain quantitatively, for the first time, the dense gas CO2 behaviour which led to the Lake Nyos disaster in 1986 that saw dense CO2 pooling and draining down valleys, causing ~1700 deaths. Neither of these applications considered (or required) a heated surface. However, the Fagradalsfjall eruption is now in a phase where lava fountains have been reported, and so the effect of surface heating will need to be considered in any modelling, to include the complex interactions and feedbacks between a dense gas, a heated surface, and the underlying meteorology. The model, after development and verification, will be available in the future as an operational hazard prediction system and and could lead to significant improvements in the UK national capability to respond to dense gas releases. This includes anthropogenic releases, for example industrial accidents and fires.

冰岛的Fagradalsfjall正在进行的爆发为观察和建模密集的火山气体行为提供了一个杰出而难得的机会。二氧化硫（SO2）是富含熔岩爆发的主要发射，例如在Fagradalsfjall。这是空气分子量的两倍以上，这很容易表现出诸如沉降之类的密集气体分散特征，并有可能显着影响数百公里尺度的分散体。这可能导致较低水平的浓度增加，并对空气质量和人类健康产生影响。该项目的目的是（a）收集表面空气质量和气象数据集，（b）产生一个模拟框架，能够模拟密集的气体并对（a）进行验证。目前不存在这样的框架。这是一个重大，限时且易于访问的喷发事件，如果对现在做出回应，可以在科学理解和对未来的管理（可能更大的，可能会引起严重的燃气危害）方面取得重大进展。 （a）我们将在Fagradalsfjall附近增强现有的空气质量观察结果，创建一个网络，以50-100公里的规模对密集的火山气体分散剂进行全面评估。这个独特的数据集将为完整的气象预测模型提供首次独立的验证，并具有致密的气体能力以及表面加热（见下文）。（b）最新模型开发工作表明，使用NCAR天气研究和预测（WRF）模型的改编版使用了有效的火山气体分散预测。该系统被用来成功解释冰岛（冰山亚）卡特拉火山的二氧化碳分散剂的测量，并首次定量解释了1986年导致NYOS湖灾难的密集气体二氧化碳行为，导致了密集的二氧化碳池，并导致了密集的二氧化碳，并驱动了山谷，导致了〜1700死亡。这些应用都没有考虑（或要求）加热的表面。但是，现在已经报告了熔岩喷泉的阶段，因此在任何建模中都需要考虑表面加热的效果，以包括一个复杂的相互作用和密集的气体，加热的表面和基础气象之间的反馈。该模型经过开发和验证后，将来将作为一种运营危害预测系统提供，并可能导致英国国家对浓缩天然气释放的能力的显着提高。这包括人为释放，例如工业事故和火灾。