Collaborative Research: Energy Release and Transport in Impulsive Phase of Solar Flares

As we continue to spread our technological reach into space, we are beginning to grasp how dangerous and inhospitable it can be. An often overlooked danger comes from the source of energy in our solar system: the Sun. The seemingly static and abiding facet of our cosmic neighborhood provides a constant and reliable stream of heat and light, but this can change in an instant and without warning. Coronal Mass Ejections (CMEs) are violent eruptions that see plasma structures hundreds of times the size of the Earth reach out of the sun and blast into space. This large concentration of unstable magnetic energy on the surface of the Sun can often be characterized by bright flashes of light, X-rays, ultraviolet and gamma rays commonly known as Solar Flares. These events are an almost daily occurrence during solar activity maxima and are a source of energetic particles and radiation which can be very harmful to space missions, communications and GPS satellites, and especially to manned space operations such as the ISS. In rare cases, these high energy phenomena may even threaten our safety on Earth: a massive solar event was felt around the world in 1859 as highly energetic solar particles rained down on our planet, creating dancing lights in the atmosphere; an aurora that stretched from the North Pole all the way to New York City. A key aspect of our Nation's continued foray into space along with well thought out plans of defense lie in the scientific characterization and understanding of such powerful and seemingly unpredictable phenomena. Safety in space is one of our most important priorities, and the key to venturing outside of our planet lies in the understanding of the energetic heart of our solar system. This three-year project addresses the fundamental problem of how the energy is produced, released and transported on the Sun during most extreme flare events. The study leads to better understanding of mechanisms of solar energetic particles and their impacts, as well as to development of advanced predictive capabilities. The project involves students at NJIT and University of Colorado who will answer outstanding questions about the fundamental physics of solar flare energy production and release. The student's results will be presented at professional conferences and summer programs, as well as also at the University student events, thus, promoting STEM education, as well as environmental and space studies.

Recent observational and modeling results showed that the standard model of solar flares, which consider that the primary energy release in the impulsive phase is in the form of high-energy electron beams, are not capable to explain the observed impacts in the solar atmosphere and the flare dynamics. Thus, it is necessary to consider other mechanisms of the energy release and transport, such as proton beams and mixed electron-proton (neutral) beams. Using currently available computational models and multi-instrument data, the team performs a comprehensive investigation and derives properties of the flaring plasma and accelerated particles during the impulsive phase. The project specific tasks are: (i) perform quantitative multi-instrument analysis of the flare emission, spectroscopic and magnetic field data; (ii) model the dynamic response of the solar atmosphere to various energy release channels (including electron, proton and neutral beams of different energy fluxes, and heat flux) by performing radiative hydrodynamics simulations; (iii) using the flare dynamical models and radiation codes, analyze the emission and spectral characteristics for the various energy release channels; and, (iv) by comparing the model characteristics with the data analysis results deduce properties of flare energy release in the impulsive phase. 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.