Volcanic plume understanding and forecasting: Integrating remote-sensing, in-situ observations and models (V-PLUS)

The 2010 Eyjafjallajökull and 2011 Grimsvötn eruptions in Iceland were stark reminders that society is increasingly vulnerable to volcanic hazards. Since 2012, volcanic eruptions are listed in the UK National Risk Register for Civil Emergencies, recognising the high potential for societal disruption and economic loss. Volcano observatories and regulatory bodies, including the nine Volcanic Ash Advisory Centres (VAACs), use a variety of tools and data to mitigate the impacts of eruptions, and ensure aviation safety. Some of the most important tools are atmospheric models that simulate the atmospheric transport and removal of volcanic plume constituents and form the backbone of the regulatory response. The accuracy of these model predictions relies on:

i) accurate input data, mainly derived from ground-based measurements and satellites;
ii) the accuracy of the model representation of volcanic plume transport and plume processes.

The overarching aims of V-PLUS are to transform our understanding of volcanic plumes and deliver methods and tools that enhance monitoring and forecasting capabilities in the UK and beyond. Our project partners and subcontractor include the Icelandic Met Office, the UK Met Office and Etna volcano observatory, which ensures that our new research breakthroughs will be used operationally by VAACs and volcano observatories. This will enhance our capabilities to mitigate the economic and societal hazards posed by volcanic eruptions.

To achieve our aims, V-PLUS will exploit data from a recently launched satellite sensor called TROPOspheric Monitoring Instrument (TROPOMI). The exceptional spectral and spatial resolution of TROPOMI, 12 times better than the previous generation of instruments, is for the first time comparable to ground-based measurements, and will be a game-changer in volcanology, providing an unprecedented opportunity to characterise and track volcanic plumes. V-PLUS will combine this new data with ground-based and other satellite data, as well as atmospheric modelling to study volcanic plumes with unprecedented fidelity. To improve our ability to measure volcanic ash from satellite imagery we will conduct experiments on volcanoes, directly sampling volcanic ash during volcanic explosions using unmanned aerial vehicles, and test numerical models of volcanic activity.

Aside from volcanic ash hazards, toxic volcanic sulphur species can degrade air quality, negatively affect human health, and potentially increase the cost of ownership of aircraft engines due to an increase in maintenance cycles. However, there is at present extremely limited knowledge of exposure thresholds and durations at which negative human health effects occur and the functioning of aircraft engines is compromised. While none of the VAACs are currently required to forecast the dispersion of volcanic sulphur, there is increasing recognition of the potential hazards from volcanic gases and their chemical conversion products. Thus, the requirement for VAACs could change in future. The chemical evolution of gases and aerosol particles controls the health and climatic impact of eruptions, and we will study this chemical evolution through experiments in accessible volcanic gas plumes.

In summary, the new atmospheric models and tools created by the V-PLUS will be rigorously tested using case study eruptions and translated into tools for direct use by VAACs and volcano observatories. Therefore, the V-PLUS project will have societal and economic benefits primarily through creating enhanced national and international capability to predict the dispersion of volcanic ash and gas plumes including their impacts on air quality, human health, climate and aviation.

Given the London Volcanic Ash Advisory Centre (VAAC) is hosted by the Met Office in Exeter, the UK has a central role in understanding and forecasting volcanic plumes. V-PLUS will have societal and economic impacts through the following key deliverables:

(i) an improved understanding of volcanic plumes and their impacts on air quality, aviation, human health, the environment, and climate, and

(ii) enhanced monitoring capabilities and national capability to forecast volcanic ash and gas dispersion enabled due to the exploitation of newly-available satellite data (such as the TROPOspheric Monitoring Instrument) and the testing and refinement of dispersion and aerosol-chemistry-climate models against a wide range of measurements.

In V-PLUS we are actively engaged with the Met Office at every stage of the project, so that the research methods and outcomes are appropriately tailored to allow an efficient pull through to operations. The direct involvement of the Met Office will also allow us to anticipate at an early stage how our findings, data and methods may impact their current practices of forecasting volcanic plume dispersion and assimilating satellite data into their forecasts. Several team members have a proven track-record of creating impact: they are involvement in hazards assessments at volcano observatories, and they advise UK Government on the risks and effects of volcanic eruptions.

We have identified three potential pathways to impact:

1. Impact on national capabilities to forecast volcanic plume dispersion and chemical evolution at the Met Office/London VAAC. The tested and refined modelling capacities produced in V-PLUS can improve the Met Office/London VAAC capabilities for its central role of forecasting volcanic ash concentrations (needed to ensure aviation safety) by delivering improved models and ways to derive eruption source terms, a critical input. Several VAACs forecast the dispersion of volcanic sulphur in order to inform their ash forecasts. This combined with the increasing recognition of the potential hazards from volcanic gases and their chemical conversion products means volcanic gas dispersal forecasting is the subject of ongoing investigation by the International Civil Aviation Organization. The 2014-15 Holuhraun eruption also highlighted a UK requirement for such capability. The V-PLUS deliverables mean that the Met Office would have a well-tested and validated system to carry out near-real time forecasting of gas-rich volcanic plumes and their potential impacts to inform Government and aviation.

2. Impact on understanding and capabilities to forecast hazards from volcanic eruptions to the UK. Since 2012, volcanic eruptions are listed on the UK National Risk Register for Civil Emergencies. In the UK, civil contingency planning and response to volcanic hazards is based on scientific evidence of the potential impacts of a volcanic eruption. In V-PLUS we will carry out impact assessments for both explosive multi-phase eruptions as well as long-lasting, gas-rich Icelandic eruptions based on the refined modelling tools created. Provision of and output from these models can have an impact on decision-making and the level of preparedness in the event of a volcanic crisis affecting the UK or UK overseas territories.

3. Impact on volcano monitoring practices. V-PLUS aims to impact on practices at volcano observatories who are charged with monitoring volcanic activity using satellite- and ground-based remote sensing. In V-PLUS, we will assess the effect of utilising new models and methods to forecast volcanic plume dispersion on practices at the London VAAC, which will benefit other VAACs and volcano observatories worldwide. For instance, we expect the automated method to derive mass fluxes and plume heights we develop in V-PLUS to create enhanced capabilities at volcano observatories around the world including ODA-listed countries (e.g. Nicaragua).