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

空间天气对电离层有各种各样的影响，电离层是地球上层大气的带电成分，位于80至1000公里之间。根据所涉及的过程，空间天气会导致电离层的密度增加或减少，或者有时会同时增加和减少。了解和预测这些影响是非常重要的，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至30兆赫之间的高频（HF）信号和~1200至1600兆赫之间的全球导航卫星（GNSS）信号进行导航。两者都受到电离层介质的充分影响，它已经决定了系统的设计，并且是一个主要的日常操作问题。我们的项目旨在确保英国气象局（以及更广泛的英国）在指定和预测电离层方面的能力得到一个阶段性的改变。为了实现我们的目标，我们将利用以前NERC、EPSRC和Dstl授予和合同的背景知识产权，并探索新技术。在杠杆IP的情况下，我们预计所有模型将在拨款结束时达到TRL 6，新的研究将在最大努力的基础上进行。我们将受益于由英国一些主要专家组成的五家机构联盟，从而实现我们的目标。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的应用的认识，特别是航空。swimmr - 1传输的核心是伯明翰大学的先进集成电子密度同化系统（AENeAS）。该模型是一个基于电离层-热层物理耦合的数据同化模型，基于最先进的集合卡尔曼滤波器。我们认为AENeAS是唯一具有完全基于物理的底层背景模型（电离层和热层）的可操作的数据同化模型。作为该计划的一部分，AENeAS将通过使用全大气群落气候模式（WACCM）对其基础数据同化和边界条件进行一些增强来进行操作和改进。改进的AeNeAS模型将提供TEC和电子密度的全球地图，并结合兰开斯特大学的d区域模型、ODRAM和莱斯特大学射线追踪专业知识的发展，将为航空业提供HF产品。虽然这些活动将增强英国模拟和预测电离层增强和消耗的能力，但它们不会直接解决GNSS系统必须面对的一些主要问题。这是由于电离层的梯度和随时间变化的信号的振幅和相位变化，即闪烁。伯明翰大学和巴斯大学的联合团队将解决这两种影响。巴斯大学将侧重于数据驱动的方法，适用于有许多GNSS电离层接收器的地区，伯明翰大学将侧重于两种风险较高的方法。其中一项，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，另一项将使用AENeAS对赤道等离子体何时何地发生强烈上升进行概率预测，这是赤道闪烁的预测器。这两种方法都适合在仪器设备较差的地区进行操作，因此潜在的收益很高，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 benefitting 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.