Physical Processes Governing Energy and Momentum Flows on Multiple Scales in Near-Earth Space Using a First-principles-based Data Assimilation System (DAS) for the Global Ionospher

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。这是一项合作项目，由犹他州立大学牵头，南加州大学和美国宇航局喷气推进实验室也参与其中。目标是首先结合多个现有的第一性原理电离层数据同化模型，开发一个能够模拟全球电离层-热层-电动力学（ITE）的模块化数据同化系统（DAS）。接下来，将构建一个多模型集成预测系统（MEPS），该系统将整合现有的具有不同物理、数值和初始条件的数据同化模型，对I-T-E系统进行建模。MEPS将允许为特定的科学研究和应用使用不同的数据同化模型进行集成建模。MEPS将是模块化的，因此它可以与低层大气（天气）模型和基于第一性原理的磁层模型耦合。因此，MEPS可以考虑向上传播的潮汐、行星波和重力波。由于MEPS重建将与可用的I-T-E测量结果一致，因此可以将自洽离子流出、对流e场、降水、电流等提供给磁层模型进行输入和/或验证。模块化的架构也意味着由其他人开发的数据同化模型（电离层、热层、电动力学）可以很容易地集成到MEPS中。此外，MEPS将包括针对近地空间领域特定部分的不同数据同化模型，这将允许使用几种不同的数据同化模型对特定事件进行集成建模。MEPS数据同化模型将提供给科学界，以便其他人可以用最先进的数据同化模型研究I-T-E系统。这些模型的使用将导致如何在近地空间研究基本物理过程的范式转变。完成后，MEPS模型（包括组件数据同化模型；电离层、电离层-等离子层、热层、高纬度电离层-电动力学和中低纬度电离层-电动力学）将交付给社区协调建模中心（CCMC），供科学界访问，并最终过渡到用于业务空间天气预报。这一努力的结果将有助于为ITE提供几个小时的预测能力，这是一个高度优先的国家空间天气需求。USU的研究生将参与该项目

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 Utah State University and with participation also from University of Southern California and NASA Jet Propulsion Laboratory. The objective is to first combine multiple existing first principles ionospheric data assimilation models to develop a modular Data Assimilation System (DAS) capable of modeling the global Ionosphere-Thermosphere-Electrodynamics (ITE). Next, a Multi-model Ensemble Prediction System (MEPS) will be constructed for modeling the I-T-E system that incorporates the existing data assimilation models with different physics, numerics, and initial conditions. MEPS will allow ensemble modeling with different data assimilation models for specific science studies and applications. MEPS will be modular so that it can be coupled to lower atmosphere (weather) models and to first-principles-based magnetosphere models. Hence, MEPS can take account of upward propagating tides, planetary waves, and gravity waves. Since MEPS reconstructions will be consistent with the available I-T-E measurements, self-consistent ion outflows, convection E-fields, precipitation, currents, etc., can be provided to magnetosphere models for inputs and/or validation. The modular architecture also means that data assimilation models (ionosphere, thermosphere, electrodynamics) developed by others can be easily incorporated in MEPS. In addition, MEPS will include different data assimilation models for specific parts of the near-Earth space domain, which will allow ensemble modeling of specific events with several different data assimilation models. The MEPS data assimilation models will be made available to the scientific community so that others can study the I-T-E system with state-of-the-art data assimilation models. The use of these models will lead to a paradigm shift in how basic physical processes are studied in near-Earth space.When completed, the MEPS model (with component data assimilation models; ionosphere, ionosphere-plasmasphere, thermosphere, high-latitude ionosphere-electrodynamics, and mid-low latitude ionosphere-electrodynamics) will be delivered to the Community Coordinated Modeling Center (CCMC) for access by the scientific community and eventual transition to use for operational space weather forecasting. The results of this effort will help provide a several hour predictive capability for the ITE that is a high priority national space weather need. Graduate students at USU will participate in the project