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

世界上百分之十的人口（即几亿人）居住在距离活火山100公里的范围内。此外，随着全球人口的增加，这个数字将会上升。在所有爆发性火山喷发期间，都会形成火山碎屑密度流（PDCs）——岩石和气体的高温混合物迅速从火山口流出。这些现象是所有火山灾害中最致命的，造成了超过三分之一的火山相关死亡。此外，伴随而来的火山灰云有可能造成全球混乱，并因空域关闭而造成重大经济损失。然而，尽管PDCs具有致命的性质，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”和危险流动中的复杂内部流动动力学。直接的内部观察是不可能的，但受控的实验室实验（PI的实验室重点）提供了一种严格研究这些隐藏现象的方法。该种子基金将与PI实验实验室的全球PDC专家团队合作，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性选择，以确保与PI实验室相结合，可以提供一个完整的研究计划，从揭示基础物理和将PDC流动模型纳入到直接的现实影响中。具体的成员包括独特的、国际知名的数值建模师，他们都开发了PDC模型来预测流量，在某些情况下，直接为世界范围内的火山绘制危险地图。来自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学研究所；英国地质调查局）的科学家将正式向国内外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明确的途径。有研究油田储层和PDC灰分特征（包括其对健康的不利影响）经验的学者将把合作成果纳入他们的工作中。最后，英国气象局是伦敦火山灰咨询中心（VAAC）的所在地，它是合作伙伴，就大气中是否存在火山灰向航空当局提供建议、预测和指导。该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)概述已知的PDC模型相关的物理参数并优先考虑缺失的物理参数；(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，作为未来长期资助申请的基础。最终的结果将是一个长期的合作伙伴关系，配备及时解决有关致命的火山碎屑流的研究问题，使用最先进的多学科方法。例如，由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PDC产生的火山灰随后在大气中的扩散。最终，这将最大限度地减少世界各地火山爆发造成的人员和经济损失，而且只有通过相互补充的全球伙伴关系才能实现这一成果。

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.