Revealing Evolution Of Electrons And Magnetic Field In Solar Flares

Modern solar physics explores the Sun through new observations with fantastically improved spectral coverage and spatial, spectral, and temporal resolutions relative to only a few years ago, brought about by recent advances in technology. In parallel, the complexity and volume of the data have been increasing proportionally. The main goal of this three-year project is to tightly couple these multi-dimensional observations with theory, analysis tools, and modeling to obtain new knowledge and make fundamental scientific discoveries in solar physics, particularly about the nature of the physical drivers of the solar activity. The solar activity depends critically on coronal magnetism, which, broadly speaking, includes magnetic field generation, control of morphology/topology, temporal evolution, and traNational Science Foundation ormation into kinetic, thermal, and non-thermal energies in the Sun's corona, as well as coupling between the magnetic and thermal structures. The ability to measure the coronal magnetic field and its changes on dynamic time scales is critically needed to uncover fundamental physics driving solar flares, eruptions, and activity. While reliable direct measurement of coronal magnetic fields has been lacking, this project aims to radically change the situation by taking full advantage of the large wealth of high resolution data and modeling that is finally becoming available. Specifically, a practical opportunity for routine use of radio observations of the Sun's corona for probing the magnetic structures involved in solar flares has recently become available for the first time from the new, fully functional microwave interferometer -- the NJIT's Expanded Owens Valley Solar Array (EOVSA) -- which has started regular interferometric observations of the Sun. To make sense of these highly demanding data, with progressively increasing volume and complexity, and to integrate these data into a full synthetic picture of the magnetic and thermal structure along with accelerated non-thermal electrons in solar flares, this project will utilize sophisticated models that combine the most advanced theories, computational codes, and simulation tools with the data.This project includes broad dissemination of the new knowledge gathered in solar radio-astronomy to enhance scientific understanding not only in solar physics, but also throughout astrophysics. The fundamental nature of EOVSA's observations ensures a broad impact on the field of solar physics, including future instrument development for the DIKIST, FASR, etc. The work will result in user-friendly software tools that will be made widely available to the solar and space weather community through the Solarsoft IDL distribution library. These modeling tools will be used during the summer internships at the NJIT's Center for Solar-Terrestrial Research (CSTR), where the project team recruits local junior high school students to participate in cutting-edge solar research. In addition, being performed within highly diverse environment provided by the CSTR at NJIT, the various project activities will advance discovery and understanding, while promoting teaching, training and learning. In particular, the easy-to-use tools to be developed during this project make great learning tools that will be widely used in graduate courses at the CSTR, such as 'Radio Astronomy,' 'Solar Physics,' and 'Plasma Physics and MHD.'The three-year project emphasizes the unique ability of EOVSA to quantify evolution of solar flares by dynamically measuring coronal magnetic fields along with the thermal and non-thermal electron distributions with high spatial and temporal resolution. The project objectives include: (i) obtain evolving maps of coronal magnetic field and electron distributions in the flaring loops; (ii) build consistent evolving three-dimensional models of solar flares that, through forward fitting, simultaneously fit all available data, including the magnetic field, radio, X-ray, EUV and others; and, (iii) provide open access to these product to the scientists and the Public. The project team will adopt an integrated research approach that brings together new microwave imaging data available from the EOVSA, data from other ground-based instruments as opportunities allow, and data from the latest space missions, coupled with advanced modeling and forward-fitting, to obtain the three-dimensional magnetic field and particle distributions in flaring loops. 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 National Science Foundation 's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.