Radio Investigations for Space Environment Research (RISER)

空间环境研究无线电调查 (RISER)

• 批准号: NE/X019004/1
• 负责人: Mario Bisi
• 金额: $ 418.61万
• 依托单位: Science and Technology Facilities Council
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FX019004%2F1
• 关键词: Radio; Investigations; Space; Environment; Research

The Earth's orbit is located within a dynamic and active interplanetary space environment where the Sun's atmosphere continually expands through the solar system (the heliosphere) to form the supersonic solar wind, which carries with it the interplanetary magnetic field. This magnetised wind continuously buffets the Earth's magnetic environment, producing space-weather effects which disrupt satellite communications and global positioning systems, are hazardous for technological infrastructures including satellites, power grids, and pipelines, and are potentially deadly for astronauts. Currently, only one hour of confirmed advance warning of the approach of adverse conditions is available provided by spacecraft directly measuring the interplanetary environment just in front of the Earth. The aim of the Radio Investigations for Space Environment Research (RISER) project is to reliably-increase that forecast time to up to four days by using a novel remote-sensing technique that allows the inner heliosphere's density and velocity structure to be imaged and assimilated into propagation models that track solar wind features and predict their arrival at the Earth. This technique uses the LOw Frequency ARray (LOFAR, the world's largest low-frequency radio-telescope) to detect radio signals from distance, astronomical radio sources, and to observe how these signals are made to twinkle (scintillate) as they pass through the turbulent heliosphere. This can also be accomplished for the Earth's ionised atmosphere (the ionosphere) to measure the impact of the Sun on Earth.The research within the RISER project is summarised as follows:1. To investigate how to increase the robustness of the "interplanetary scintillation" (IPS) technique (twinkling of radio stars) using LOFAR, and how to upgrade LOFAR such that it can make continuous observations of the inner heliosphere (LOFAR for Space Weather, LOFAR4SW), while allowing its other scientific observations to continue simultaneously.2. To optimise the assimilation of IPS data into propagation models that can forecast how the solar wind structures will evolve as they move through the inner heliosphere and the timing of their arrival at Earth.3. Investigate comprehensive observations and measurements of the response of the Earth's space environment, and assess the impact of the heliospheric structures on the terrestrial environment: i.e. the "geoeffectiveness" of different heliospheric structures will be measured, indicating how hazardous they are for technological systems.Space weather is hazardous for many operators and end-users of technological systems. Reliable mitigation strategies for many of these technologies depend on accurate forecasting of the likely impact of space-weather conditions on operations. RISER will provide both improved forecasting and improved understanding of the impact of different heliospheric structures on geospace and technological systems within it. Improving advanced warning of approaching hazards from one hour to four days will be a major benefit to society. RISER shall indeed identify those results and model improvements that can be earmarked as strong candidates for eventual operational implementation at the Met Office.Therefore, with our holistic approach, this project aims to (A) investigate how LOFAR can be utilised for continuous and systematic tracking and detection of heliospheric structures; (B) advance the understanding of how the Earth's space-environment/ionised-atmosphere system responds to the interaction between heliospheric structures tracked through observations using LOFAR and the Earth's own magnetic field; (C) advance the capability of space-weather predictions by assimilating information from the continuous LOFAR tracking, the Earth space-environment response, and the impact caused to technologies on Earth; and (D) identify which RISER research outcomes can be exploited for improved operational space weather forecasts.

地球轨道位于一个动态和活跃的行星际空间环境中，太阳大气层在太阳系（日光层）中不断膨胀，形成超音速太阳风，太阳风携带行星际磁场。这种磁化风持续冲击地球的磁环境，产生空间天气效应，破坏卫星通信和全球定位系统，对包括卫星，电网和管道在内的技术基础设施构成危险，并可能对宇航员造成致命伤害。目前，直接测量地球前方行星际环境的航天器只能提供一个小时的关于不利条件接近的确认预警。空间环境研究无线电调查（RISER）项目的目的是通过使用一种新的遥感技术，将日光层内部的密度和速度结构成像并纳入传播模型，跟踪太阳风特征并预测其到达地球的时间，从而可靠地将预测时间增加到四天。这种技术使用低频阵列（LOFAR，世界上最大的低频射电望远镜）来探测来自远处天文射电源的无线电信号，并观察这些信号在穿过湍流的日光层时如何闪烁（闪烁）。这也可以通过测量地球电离层来测量太阳对地球的影响。RISER项目的研究内容概括如下：1.研究如何使用LOFAR增强“行星际闪烁”技术（射电星闪烁）的稳健性，以及如何升级LOFAR，使其能够对日光层内部进行连续观测（LOFAR for Space Weather，LOFAR 4SW），同时允许其其他科学观测继续顺利进行。优化IPS数据到传播模型的同化，该模型可以预测太阳风结构在穿过日光层内部时如何演变以及它们到达地球的时间。调查对地球空间环境响应的全面观测和测量，并评估日光层结构对地球环境的影响：即将测量不同日光层结构的“地球效率”，表明它们对技术系统的危害程度。其中许多技术的可靠减缓战略取决于对空间气象条件可能对运行产生的影响的准确预测。RISER将提供改进的预报和更好地了解不同日光层结构对地球空间及其技术系统的影响，将接近危险的预警从一小时提高到四天，这将是对社会的一个重大好处。RISER将确定那些结果和模型的改进，这些结果和模型的改进可以被指定为气象局最终业务实施的强有力的候选者。因此，通过我们的整体方法，本项目旨在（A）研究如何利用LOFAR对日光层结构进行连续和系统的跟踪和探测;（B）增进对地球空间环境/电离大气层系统如何对通过使用LOFAR观测跟踪的日光层结构与地球自身磁场之间的相互作用作出反应的了解;（C）通过吸收来自连续LOFAR跟踪、地球空间环境响应以及对地球技术造成的影响的信息，提高空间天气预报的能力;（D）确定哪些RISER研究成果可以用于改进业务空间天气预报。