Advanced Space Weather Modeling

该项目旨在在对空间气象的认识方面取得突破性进展。空间气象涉及影响人类生活和技术的日地系统动态过程。最具破坏性的空间天气形式，从电力中断到对宇航员的辐射危害，都是由于重大的太阳爆发：快速日冕物质抛射和爆发性X级耀斑。这些破坏性事件起源于太阳内部出现的磁场，形成了CME爆发到日光层的活跃区域。当撞击地球时，行星际日冕物质抛射会撞击磁层并产生磁暴。这个过程是由磁重联的微观物理学控制的。该项目的目标是回答空间天气最突出的问题：磁能的积累如何导致太阳爆发，以及磁场重联如何导致地磁风暴。提高空间气象模型的预测能力将产生重大的社会效益。此外，学生将广泛参与该项目，该项目将使用一个复杂的多尺度模型，即空间气象建模框架，该框架可详细反映全球系统中的小尺度物理学。SWMF包含十几个不同的模型，可以模拟太阳-地球系统的各种物理领域，从太阳对流区到太阳日冕，日光层，全球和内部磁层，电离层和地球高层大气。通量出现和CME启动的模拟将进行我们的高分辨率磁流体动力学程序BATS-R-US。模拟区域从对流区延伸到日冕。 为了模拟重联过程，该项目将使用扩展的磁流体动力学嵌入粒子-细胞（MHD-EPIC）方法。 MHD-EPIC对全球大部分系统使用高效的MHD代码。SWMF的地球空间模型最终将被转移到国家气象局的空间天气预报中心运行。此外，SWMF也向其他研究人员公开。

The project aims to achieve breakthrough advances in the understanding of space weather. Space weather involves the dynamical processes of the Sun-Earth system that affect human life and technology. The most destructive forms of space weather, ranging from electrical power disruptions to radiation hazards for astronauts, are due to major solar eruptions: fast coronalmass ejections (CMEs) and eruptive X-class flares. These destructive events originate with magnetic fields emerging from the solar interior, forming the active regions from where CMEs erupt into the heliosphere. Upon impacting the Earth, interplanetary CMEs impact the magnetosphere nd produce geomagnetic storms. This process is controlled by the microphysics of magnetic reconnection. The project's goal is to answer the most salient questions of space weather: how the buildup of magnetic energy results in solar eruptions and how magnetic reconnection results in geomagnetic storms. Improving the predictive capabilities of space weather models will have major societal benefits. Moreover, there will be extensive student involvement in the project.The project will use a sophisticated multi-scale model, the Space Weather Modeling Framework(SWMF) that can represent detailed small-scale physics in a global system. The SWMF contains more than a dozen different models that can simulate various physics domains of the Sun-Earth system starting from the solar convection zone coupled to the solar corona, the heliosphere, the global and inner magnetosphere, and the ionosphere and upper atmosphere of the Earth. The flux emergence and CME initiation simulations will be carried out with our high-resolution magnetohydrodynamic code BATS-R-US. The simulation domain extends from the convection zone into the corona. To model the reconnection process, the project will use the extended magnetohydrodynamics with embedded particle-in-cell (MHD-EPIC) method. MHD-EPIC uses the efficient MHD code for most of the global system.The Geospace models of the SWMF will eventually be transferred to operation at the Space Weather Prediction Center of the National Weather Service. Also, the SWMF is publicly available to other researchers.