NI: Pyroclastic Density Current Partnership (PDCP): A global partnership to align numerical models and experimental techniques.

世界上10%的人口(即数以亿计的人)生活在活火山周围100公里以内。此外，随着全球人口的增加，这一数字将会上升。在所有爆炸性的火山喷发期间，火山碎屑密度流(PDC)可以形成高温的岩石和气体混合物，并迅速从火山口流出。这些现象是所有火山灾害中最致命的，导致了三分之一以上的与火山有关的死亡。此外，伴随而来的火山灰云有可能造成全球破坏，并因空域关闭而造成重大经济损失。然而，尽管药物管制区具有致命性，但我们目前缺乏准确的模型来预测这些流动，因此任何危险地图和缓解战略本身都是有限的。为了改进我们的数值模型，我们需要了解这些“不透明”和危险流动中复杂的内部流动动力学。直接的内部观察是不可能的，但受控实验室实验(PI的实验室重点)提供了一种严格研究这些原本隐藏的现象的方法。该种子基金将与PI的实验实验室合作一支由全球PDC专家组成的免费团队，以使未来的实验工作与PDC数值模型保持一致。这一合作伙伴关系的成员经过战略选择，以确保与PI的实验室相结合，能够交付完整的研究计划-从解开基本物理和纳入PDC流动模型到直接影响现实世界。具体来说，成员包括独特的、国际知名的数值模型师，他们都开发了预测流量耗尽的PDC模型，在某些情况下，还直接为世界各地的一系列火山提供危险地图。来自相关政府机构和火山观测站网络(如意大利国家地球物理和火山研究所；英国地质调查局)的科学家将正式向国内和国际政府通报火山灾害和风险方面的进展，从而为这一新伙伴关系的影响提供一条明确的途径。具有研究PDC火山灰的实地矿藏和特征，包括其对健康的不利影响的经验的学者将把伙伴关系的成果纳入他们的工作。最后，英国气象局是伦敦火山灰咨询中心(VAAC)的总部所在地，是向航空当局提供关于大气中火山灰存在情况的建议、预测和指导的合作伙伴。这一种子基金将支持一系列研讨会和实验室交流访问，成员将：(1)概述与PDC模型相关的已知物理参数并确定缺少的物理参数的优先顺序；(2)共同设计试点实验，以填补这些知识空白；(3)产生概念验证数据，作为未来长期赠款申请的基础。最终结果将是一种长期的合作伙伴关系，这种伙伴关系有能力使用最先进的多学科方法来解决围绕致命的火山碎屑流的及时研究问题。例如，该团队领导的后续研究将预测致命火山碎屑流的空间范围，以及随后PDC产生的火山灰在大气中的扩散。归根结底，这将最大限度地减少世界各地火山爆发带来的人员和经济成本，这是一个只有通过互惠互利的全球伙伴关系才能实现的结果。

Ten percent of the world's population (i.e. 100s of millions) live within 100 km of an active volcano. Furthermore, this number is set to rise with the increasing global population. During all explosive volcanic eruptions pyroclastic density currents (PDCs) can form - high temperature mixtures of rock and gas that rapidly flow away from the volcanic vent. These phenomena are the most lethal of all volcanic hazards and are responsible for more than a third of volcanic related fatalities. Furthermore, the accompanying ash clouds have the potential to cause global disruption and significant economic loss due to air-space closure. However, despite the lethal nature of PDCs we currently lack accurate models to forecast these flows and thus any hazard maps and mitigation strategies are inherently limited. To improve our numerical models we need to understand the complex internal flow dynamics within these 'opaque' and hazardous flows. Direct internal observation is not possible, but controlled laboratory experiments (PI's lab focus) offer a way to rigorously study these otherwise hidden phenomena. This seedcorn fund will partner a complimentary team of global PDC experts with the PI's experimental laboratory to align future experimental efforts with numerical PDC models. The members of this partnership have been strategically selected to ensure that, in combination with the PI's lab, a full research programme can be delivered - from unravelling the fundamental physics and incorporation into PDC flow models to direct real-world impact. Specifically members include unique, internationally renowned, numerical modelers who have all developed PDC models to forecast flow run-out and, in some cases, directly inform hazard maps for a range of volcanoes worldwide. Scientists from the government agencies and volcano observatory networks involved (e.g. the Italian National Institute of Geophysics and Volcanology; the British Geological Survey) will formally communicate advances in volcanic hazard and risk to domestic and international governments, thereby providing a clear pathway to impact from this new partnership. Academics who have experience working on the field deposits and characteristics of PDC ash, including their adverse health effects, will incorporate the partnership outcomes into their work. Finally, the Met Office, home to the London Volcanic Ash Advisory Centre (VAAC), are partners who provide advice, forecasts and guidance to the aviation authorities on the presence of volcanic ash in the atmosphere. This seedcorn fund will support a series of workshops and laboratory exchange visits where members will: (1) outline the known and prioritise the missing physical parameters relevant for PDC models; (2) co-design pilot experiments to fill these knowledge gaps and (3) produce proof-of-concept data that will be used as a basis for future, longer term grant applications. The final outcome will be a long-lasting partnership that is equipped to tackle timely research questions surrounding deadly, pyroclastic flows using state-of-the-art multidisciplinary methods. Subsequent research led by this team will, for example, forecast the spatial extent of deadly pyroclastic flows and the subsequent atmospheric dispersal of PDC produced, volcanic ash. Ultimately this will minimise the human and economic cost of explosive volcanic eruptions around the world and is an outcome only achievable through complimentary, global partnership.