Space Weather Instrumentation, Measurement, Modelling and Risk: Ionosphere (SWIMMR-I)

空间天气对电离层有各种影响，电离层是位于80至1000公里之间的地球高层大气的带电部分。根据所涉及的过程，空间天气导致电离层密度增强、耗尽或有时结构化为增强和耗尽。了解和预测这些影响非常重要，因为各种无线电应用和部门都受到电离层的影响。例如，军事和民用航空部门使用频率在3和30 MHz之间的高频（HF）信号和频率在~1200和1600 MHz之间的全球导航卫星（GNSS）信号用于导航。两者都受到电离层介质的充分影响，它决定了系统的设计，是一个主要的日常业务问题。我们的计划旨在确保气象局（更广泛地说，英国）的能力，以确定和预测电离层的一个步骤的变化。为了实现我们的目标，我们将利用以前NERC，EPSRC和Dstl赠款和合同的背景知识产权，并探索新技术。在杠杆知识产权的情况下，我们预计所有模型将在TRL 6的资助结束和新的研究将尽最大努力的基础上。我们将通过受益于一个由英国主要专家组成的五个机构联盟来实现我们的目标，为了最大限度地交流思想，我们将通过向更广泛的英国和国际社会的其他成员开放我们的技术会议来加强联盟。该计划的大部分将集中在环境模型上，但在这样做的同时，我们将保持对这些模型应用的认识，位于SWIMMR-I交付中心的是伯明翰大学的先进电子密度同化系统（AENeAS）。该模型是一个基于电离层-热层物理学的耦合数据同化模型，以集合卡尔曼滤波器的最新变体为基础。我们相信AENeAS是唯一一个具备完全物理基础的基本背景模型（电离层和热层）的可操作数据同化模型。作为该方案的一部分，AENeAS将通过使用全大气社区气候模式（WACCM）对其基本数据同化和边界条件进行一些改进来实现业务化和改进。改进后的AeNeAS模型将提供TEC和电子密度的全球地图，并与兰开斯特大学D区模型ODRAM的发展和莱斯特大学射线追踪专业知识的发展相结合，将为航空业提供高频产品。这些活动将提高英国模拟和预测电离层增强和耗尽的能力，它们不会直接解决全球导航卫星系统必须面对的一些主要问题。这是由于电离层中的梯度以及信号上随时间变化的幅度和相位变化，即闪烁。伯明翰大学和巴斯大学的一个联合小组将研究这两种影响。巴斯大学将侧重于适用于有许多全球导航卫星系统电离层接收器的区域的数据驱动方法，伯明翰大学将侧重于两种风险较高的方法。在其中一个项目中，伯明翰大学将使用卫星无线电掩星测量来定位和量化闪烁，在另一个项目中，使用AENeAS对赤道等离子体何时何地发生强烈抬升进行概率预测，这是赤道闪烁的预测器。这两种方法都适用于在仪器设备不足的地区进行操作，因此潜在的好处很高，但存在重大的相关研究挑战。

Space weather has a variety of effects on the ionosphere which is the charged component of the Earth's upper atmosphere lying between 80 and 1000 km. Depending on the processes involved, space weather causes the density of the ionosphere to be enhanced, depleted, or sometimes structured into both enhancements and depletions. Understanding and forecasting these effects is of great importance, because a variety of radio applications and sectors are affected by the ionosphere. For example, the military and civil aviation sectors use both high frequency (HF) signals, at frequencies between 3 and 30 MHz, and global navigation satellite (GNSS) signals, between ~1200 and 1600 MHz, for navigation. Both are sufficiently affected by the ionospheric medium that it has determined the system design and is a major day-to-day operational issue.Our programme seeks to secure a step-change in the Met Office's (and more broadly the UK's) ability to specify and forecast the ionosphere. To achieve our objectives, we will leverage background IP from previous NERC, EPSRC and Dstl grants and contracts and explore new techniques. In the case of the leveraged IP we expect that all models will be at TRL 6 by the grant end and new research will be on a best efforts basis. We will achieve our objectives by benefiting from a five-institution consortium of some of the country's principal experts and, to maximise interchange of ideas, we will enhance the consortium by opening our technical meetings to other members of the wider UK and international community.The majority of the programme will focus on environmental models, but while doing this we will maintain an awareness of the applications for these models, in particular aviation.Lying at the heart of the SWIMMR-I delivery is the University of Birmingham's Advanced Ensemble electron density Assimilation System (AENeAS). This model is a coupled ionosphere-thermosphere physics-based data assimilation model and is based on a state-of-the-art variant of the ensemble Kalman filter. We believe that AENeAS is the only operationally- ready data assimilation model which has a fully physics-based underlying background model (ionosphere and thermosphere). As part of this programme AENeAS will be both operationalised and improved through a number of enhancements to its underlying data assimilation and boundary conditions using the Whole Atmosphere Community Climate Model (WACCM). The improved AeNeAS model will provide global maps of TEC and electron density, and in combination with developments of the University of Lancaster's D-region model, ODRAM, and developments of the University of Leicester's ray tracing expertise, will provide HF products to the aviation industry.While these activities will enhance the UK's ability to model and forecast ionospheric enhancements and depletions, they will not directly address some of the major problems that GNSS systems have to face. These are due to gradients in the ionosphere and time dependent amplitude and phase variations on the signal, known as scintillation. Both effects will be addressed by a joint team from the Universities of Birmingham and Bath. The University of Bath will focus on a data driven approach appropriate to regions where there are many GNSS ionospheric receivers and the University of Birmingham will focus on two higher risk approaches. In one, the University of Birmingham will use satellite radio occultation measurements to localise and quantify scintillation, and in the other use AENeAS to make probabilistic predictions of when and where strong uplift of the equatorial plasma occurs, a predictor of equatorial scintillation. Both of these approaches are suitable for operation over poorly instrumented areas and consequently the potential benefits are high, but there are significant associated research challenges.