The physics controlling radiation belt dynamics

这项研究将调查在近地空间内被称为内辐射带和外辐射带的区域内支配“空间天气”效应的物理过程。当地球辐射带的高能粒子含量显著增加的时候，就是“空间天气”的重大意义所在。加强辐射带对在辐射带内运行的卫星基础设施和以磁性方式映射到这些区域的地面系统的不利影响可产生重大的社会经济影响。英国国家民用紧急情况风险登记机构将空间天气列为一种发生几率较高、对英国社会影响较大的新风险。根据英国首相和美国总统的高级科学顾问的说法，仅在美国，一次极端太空天气事件在接下来的一年里的潜在成本估计为2万亿美元，预计需要4-10年的恢复期。此外，预计在这些扰动期间从辐射带逃逸的粒子也会通过改变高层大气中的氮氧化物水平而对大气化学产生一些影响，从而影响全球气温。因此，需要研究支配空间天气效应的一般物理过程，特别是地球内外辐射带的动力学，不仅要了解如何减轻这些扰动的社会经济影响，而且要更全面地了解全球气候变化。在扰动的空间天气事件中，辐射带可能会变得充满能量、耗尽或完全消失，有时只是朝向或远离地球。事实上，观测表明，在某些事件期间，可能会形成第三条带。这些突然而戏剧性的变化被认为是电磁波捕获辐射带中的粒子，通过辐射带传输粒子，并将粒子散射到地球大气中的结果。目前，这些过程都没有得到充分的了解，需要更好地量化这些过程的各种驱动因素之间的联系和相互作用，以便推动我们对辐射带动态的理解。因此，这项研究的最终目标是确定控制辐射带中粒子动力学的电磁波类型，并发现这些相互作用导致辐射带通电、耗尽和/或移动的条件。这项研究将有助于开发能够预测辐射带状况的基于物理的预测模型，以帮助制定减轻空间天气对现代社会影响的战略。

This research will investigate the physical processes governing 'Space Weather' effects within the regions of near-Earth space known as the inner and outer radiation belts. Times when the energetic particle content of the Earth's radiation belts becomes dramatically enhanced are of great 'Space Weather' interest. The adverse consequences of radiation belt enhancements for both satellite infrastructure operating within the radiation belts and to ground-based systems which magnetically map to these regions can have a significant socio-economic impact. The UK National Risk Register for Civil Emergencies has classified Space Weather as a new risk with relatively high chance of occurrence and high impact on UK society. According to senior science advisors to the UK Prime Minister and the US President, the potential cost of an extreme Space Weather event is estimated as $2 Trillion in the following year, in the U.S. alone, with a projected need for a 4-10 year recovery period. Moreover, particles escaping from the radiation belts during these disturbed periods are also predicted to have some impact on atmospheric chemistry and as a result global temperature by altering Nitrogen Oxide levels in the upper atmosphere. Thus research into physical processes governing Space Weather effects in general and the dynamics of the Earth's inner and outer radiation belts in particular is required to not only learn how to mitigate the socio-economic impact of these disturbances but also to more fully understand global climate change.During disturbed Space Weather events the radiation belts may become energised, depleted or completely disappear, and sometimes simply move toward or away from the Earth. In fact, observations demonstrate that during certain events a third belt can form. These abrupt and dramatic changes are thought to be the result of electromagnetic waves trapping particles in the radiation belts, transporting particles through the belts, and scattering particles into the Earth's atmosphere. At present, none of these processes are fully understood, and the links and interactions between the various drivers of these processes need to be better quantified in order to move our understanding of the dynamics of the radiation belts forward. The ultimate goal of this research is thus to determine the types of electromagnetic waves which control particle dynamics in the radiation belts and to discover the conditions under which these interactions lead to the energisation, depletion, and/or movement of the belts. This research will allow the development predictive physics-based models which can forecast the state of the radiation belts in order to help develop strategies to mitigate the effects of space weather on modern society.