Collaborative Research: Integration of Extended Magnetohydrodynamic (MHD) and Kinetic Effects in Global Magnetosphere Models

这笔资金用于部分支持2012年NASA-NSF空间天气建模合作伙伴关系选定并资助的项目。这是一项合作努力，由普林斯顿大学领导，新罕布什尔大学、加州大学圣地亚哥分校、美国宇航局戈达德太空飞行中心和洛斯阿拉莫斯国家实验室也参与其中。目标是承担一个理论和计算上的巨大挑战，即开发一个最先进的全球磁层模型，超越电阻MHD模型的标准框架，包括多流体物理，包括广义欧姆定律，包含动力学效应的电子和离子的增强状态方程，以及多种带电粒子。为此，该项目将在全球磁层代码（OpenGGCM）的框架内吸收并代表过去近15年来在我们对重联、电流片不稳定性、多种流体和无碰撞等离子体湍流的理解方面取得的许多显著进展，该代码的传统版本目前在社区中广泛使用。一套成熟的基于物理的模块，基于高伦德奎斯特数MHD、霍尔MHD、混合、多物种和完全动力学的细胞内粒子代码，将在团队成员中存在，并将汇集在一起，产生一个全面的下一代全球磁层代码，该代码将首次包括扩展的MHD和动力学效应。完成后，由此产生的增强全球磁层模型将交付给社区协调建模中心（CCMC），方便科学界全面访问，并最终过渡到用于业务空间天气预报。这将使对对人类社会有直接影响的极端空间天气事件的动力学尺度过程（例如，磁重联）的精确建模成为可能。虽然该应用程序是针对地球磁层的，但该模型的核心科学模块具有更广泛的适用性，并且对我们理解和预测日球层中涉及磁重联、电流片不稳定和湍流的广泛空间天气现象的能力具有潜在的变革性意义。该团队是学术界和国家实验室之间的合作伙伴关系，由几位初级科学家，博士后研究员和研究生组成，他们将在这个广泛的跨学科学科中接受教育，涉及理论和实验空间等离子体物理，应用数学和高性能计算。

This grant is for partial support of a project selected and funded under the 2012 NASA-NSF partnership for Space Weather Modeling Collaborations. It is a collaborative effort, led by Princeton University and with participation also from University of New Hampshire, University of California-San Diego, NASA Goddard Space Flight Center, and Los Alamos National Laboratory. The objective is to undertake what amounts to a theoretical and computational grand challenge, namely to develop a state-of-the-art global magnetosphere model that goes beyond the standard framework of the resistive MHD model to include multi-fluid physics, including a generalized Ohms' law, enhanced equations of state for electrons and ions that incorporate kinetic effects, and multiple charged particle species. To this end, the project will assimilate and represent many of the remarkable advances made over the last almost 15 years in our understanding of reconnection, instabilities of current sheets, multiple fluids, and turbulence in collisionless plasmas within the framework of a global magnetosphere code, the OpenGGCM, a traditional version of which is presently used extensively in the community. A suite of mature physics-based modules, based on high-Lundquist-number MHD, Hall MHD, hybrid, multi species, and fully kinetic particle-in-cell codes exist amongst the team members and will be brought together to produce a comprehensive, next-generation global magnetosphere code that will include for the first time extended MHD and kinetic effects. When completed, the resulting enhanced global magnetosphere model will be delivered to the Community Coordinated Modeling Center (CCMC) for easy and full access to the scientific community and eventual transition to use for operational space weather forecasting. This will enable the accurate modeling of the kinetic scale processes (e.g., magnetic reconnection) responsible for extreme space weather events with direct impact on human society. While the application is geared to the Earth's magnetosphere, the core science module of the model has much broader applicability, and has potentially transformative implications for our ability to understand and predict a broad range of space weather phenomena in the heliosphere that involve magnetic reconnection, instabilities of current sheets, and turbulence. The team, which is a partnership between academia and national laboratories, consists of several junior scientists, postdoctoral fellows, and graduate students who will be educated in this broadly interdisciplinary subject, involving theoretical as well as experimental space plasma physics, applied mathematics, and high-performance computing.