MOSAIC Digital Environment Feasibility Study

人们越来越意识到空间天气所产生的危害，这些危害现已列入英国国家风险登记册（内阁办公室，2018年）。一个重大的风险是由含有大量高能粒子的“硬”太阳粒子事件造成的，这可能导致地面上现代微电子技术的腐败和破坏。一般来说，这样的太阳事件可以在地球表面被地面中子监测器检测到，并被称为地面增强（GLE）：它们通常持续数小时，有史以来最强烈的测量是在1956年2月在英国。然而，在20世纪40年代之前，我们只能从冰芯和树木年轮中间接测量GLE（Miyake等人，2012; Mekhaldi等人，2015）。对10 Be、36 Cl和14 C的观测结果显示，在AD 774中，1956年2月的事件比1956年2月的事件大30倍，在AD 994中，1956年2月的事件比1956年2月的事件大15倍。在当今的技术社会中，GLE对复杂系统构成了危害，例如自动驾驶汽车，铁路，核电站，特别是飞机（包括无人驾驶航空平台），这些系统是迄今为止暴露最多的。目前，英国没有地面中子测量能力，因为这是在20世纪80年代放弃的。大气电离合作湿度传感器（MOSAIC）项目的主要目标是研究英国COSMOS土壤湿度传感器网络的双重用途，以提供前所未有的，高密度，可持续和具有成本效益的英国空间天气测量能力，为关键基础设施提供实时警报，并实现新的环境科学。COSMOS是一个相对较新且不断扩展的传感器网络，目前英国有近50个探测器由NERC生态和水文中心（CEH）运营。宇宙射线在大气层高处产生的中子可以到达地面，其中一些中子将根据土壤湿度被反射：COSMOS台站测量反射的中子，以确定当地的平均土壤湿度。除了研究基础设施（包括航空）的业务预警的前景有机会创造一个长期的地面水平中子辐射记录在英国，这可以是更好的环境模型和改进的风险评估的基础上government.The研究COSMOS敏感性GLEs沿着与数字网络的可行性问题，这将产生双重用途的网络。考虑到GLE上升时间可能为分钟量级，初始优先事项是研究MOSAIC所需的显著更高时间分辨率的实用性。我们将研究实现从传感器到中心的数据非常快速的通信的可行性，其中决定是否需要发出警报以及这可能需要多长时间。COSMOS数字网络的地理多样性和分布式性质可能通过与传统的“单点”监视器相比的固有冗余提供显著的鲁棒性益处。为了协助这项工作，英国气象局将作为该系统的主要“用户”，并将就其数据分发和处理要求提供建议，我们将研究人工智能如何更好地区分所需信号并提高决策准确性。我们还将研究如何将MOSAIC与萨里智能手机大气电离辐射网络或SAIRA集成，该网络已经证明了公民科学方法可以从飞机上获得补充辐射数据。

There is growing awareness of the hazards arising from space weather which are now listed on the UK National Risk Register (Cabinet Office, 2018). One significant risk is created by 'hard' solar particle events containing a significant flux of highly energetic particles which can lead to corruption and damage in modern microelectronic technology at ground level. In general such solar events are detectable at the earth's surface by ground level neutron monitors and are termed ground level enhancements (GLEs): they typically have durations of some hours and the most intense ever measured was in February 1956 in the UK. Prior to the 1940s however we have only indirect measurements of GLEs from ice cores and tree rings (Miyake et al, 2012; Mekhaldi et al, 2015). Results on 10Be, 36Cl and 14C show events some 30 times larger than February 1956 in AD774 and 15 times larger in AD994. In today's technological society GLEs present a hazard to complex systems, such as autonomous vehicles, railways, nuclear power stations and especially aircraft (including unmanned aerial platforms) which are by far the most exposed. At present the UK has no ground level neutron measurement capability as this was abandoned in the 1980s. The main objective of the Moisture Sensors for Atmospheric Ionising Collaboration (MOSAIC) project is to study dual-purposing the UK COSMOS soil moisture sensor network to provide an unprecedented, high-density, sustainable and cost-effective UK space weather measurement capability to provide real-time alerts for critical infrastructure as well as enabling new environmental science. COSMOS is a relatively new and expanding network of sensors and there are now nearly 50 detectors across the UK operated by the NERC Centre for Ecology and Hydrology (CEH). Neutrons generated by cosmic-rays high in the atmosphere can reach ground level, some of which will be reflected dependent on the soil moisture content: COSMOS stations measure the reflected neutrons to determine average soil moisture over the local area. Besides studying the prospect of operational warnings for infrastructure (including aviation) there is an opportunity to create a long term record of ground level neutron radiation in the UK which can be the basis of better environmental models and improved risk assessments for government.The study examine COSMOS sensitivity to GLEs along with the digital network feasibility issues which would arise when dual-purposing the network. An initial priority is to examine the practicality of significantly higher temporal resolution which will be needed for MOSAIC given that GLE rise times can be of the order of minutes. We will examine the feasibility of achieving very rapid communication of data from the sensors to the centre(s) where decisions are taken on the need to issue alerts and how long this might take. It is likely that the geographical diversity and distributed nature of the COSMOS digital network could offer significant benefits for robustness via the inherent redundancy compared to conventional 'single point' monitors. To assist this work the Met Office will act as the primary 'user' of the system and will advise on their data distribution and processing requirements and we will investigate how artificial intelligence can better distinguish the wanted signal and enhance decision accuracy. We will also investigate how MOSAIC can be integrated with the Surrey Smartphone Atmospheric Ionising RAdiation network or SAIRA which has already demonstrated a citizen science approach to obtain complementary radiation data from aircraft.