Critical Assessment of the Three-dimensional (3D) Standard Model of Solar Eruptions Using a Data-driven MagnetoHydroDynamic (MHD) Approach

GSTDTAP

项目编号	1841962
	Critical Assessment of the Three-dimensional (3D) Standard Model of Solar Eruptions Using a Data-driven MagnetoHydroDynamic (MHD) Approach
	Stuart Gilchrist (Principal Investigator)
主持机构	NorthWest Research Associates, Incorporated
项目开始年	2019
	2019-05-15
项目结束日期	2022-04-30
资助机构	US-NSF
项目类别	Standard Grant
项目经费	341489(USD)
国家	美国
语种	英语
英文摘要	Theoretical models of solar eruptions are supported by numerical MHD calculations that use simple magnetic and velocity fields. The Sun, however, is much more complex, and it is therefore unclear whether models that work under ideal conditions resemble on the actual Sun. The aim of this three-year research project is to test a popular model of solar eruptions, "the standard 3D model," under realistic conditions by modeling real eruptions using photospheric observations to drive active-region-scale coronal MHD simulations. The project team will devote a significant amount of time and effort to compare their numerical simulations to real solar observations. The research study will have three parts: (i) perform data-driven MHD simulations; (ii) compare the simulations with observations; and, (iii) use the simulations to test predictions of "the standard 3D model." For a sample of eruptive regions, the project team will construct nonlinear force-free extrapolations from vector magnetograms, about an hour before each eruption. These extrapolations will be used to initialize the zero-beta MHD simulations driven by flow maps inferred from spectro-polarimetric data using optical-flow methods that treat the induction equation consistently. The team will also model a set of non-eruptive regions as an important control: they will aim to demonstrate that their method does not produce eruptions when none occurs in reality. They will use their simulations to test the predictions of "the standard 3D model" regarding the instability mechanism responsible for eruption (e.g., torus instability) and mode of reconnection during the eruption (e.g., slipping reconnection). The inclusion of control regions will indicate whether or not these features are essential for an eruption to occur, and not just simply being present but remain unimportant during the eruption process. The team will identify the instability mechanism, sites and nature of reconnection in their simulations. To date, "the standard 3D model" of solar eruptions has been tested extensively using MHD simulations with simple bipolar magnetic fields. This three-year research project takes the important next step to test the model under realistic conditions. The intellectual merit of this work is to establish the viability of "the standard 3D model." The project also aims to provide new physical insight into the basic mechanisms of magnetic energy storage and release in the solar atmosphere, which are important in a general astrophysical context. A novel aspect of the research project is the significant amount of work devoted to validating the data-driven MHD simulations; although this type of simulations is becoming increasing common in recent years, their validation is typically of a secondary consideration and it often relies on by-eye comparisons between EUV loops and field lines from the simulation, for example. The project team will devote a significant amount of time and effort to developing metrics for making quantitative comparisons between simulations and observations, which is a necessary step for objective validation. The anticipated results of this three-year project will be of interest to the space weather community: an improved understanding of solar eruptions will also improve our predictive capability for these events. The methodology and metrics for comparing numerical simulations to real observations that will be developed as part of this project will be of general use to the solar community; the project team will make their tools available to the broader community online. All their project data will be made available to the public too. The team also plans to organize a special session at the SHINE Workshop in the last year of the project focused on critically assessing the 3D standard model using different MHD models. The research and EPO agenda of this project supports the Strategic Goals of the AGS Division in discovery, learning, diversity, and interdisciplinary research. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/213016
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Stuart Gilchrist .Critical Assessment of the Three-dimensional (3D) Standard Model of Solar Eruptions Using a Data-driven MagnetoHydroDynamic (MHD) Approach.2019.