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

随着我们继续将我们的技术延伸到太空，我们开始意识到这可能是多么危险和不适宜居住。一个经常被忽视的危险来自我们太阳系的能源：太阳。我们的宇宙邻居看似静态和持久的一面提供了持续和可靠的热流和光流，但这种情况可能会在瞬间发生变化，而且没有任何警告。日冕物质抛射(CME)是一种猛烈的喷发，它看到数百倍于地球大小的等离子体结构从太阳伸向太空。太阳表面的这种不稳定磁能的大量集中，通常以明亮的闪光、X射线、紫外线和伽马射线为特征，通常被称为太阳耀斑。这些事件几乎每天都在太阳活动高峰期发生，是高能粒子和辐射的来源，可能对空间飞行任务、通信和全球定位系统卫星，特别是对国际空间站等载人空间作业非常有害。在极少数情况下，这些高能现象甚至可能威胁到我们在地球上的安全：1859年，世界各地都感受到了一次大规模的太阳事件，高能量的太阳粒子像雨点一样落在我们的星球上，在大气中产生了舞动的灯光；极光从北极一直延伸到纽约市。我国继续向太空进军以及深思熟虑的防御计划的一个关键方面在于科学地描述和理解这种强大和看似不可预测的现象。太空安全是我们最重要的优先事项之一，而冒险走出我们的星球的关键在于理解我们太阳系的能量核心。这个为期三年的项目解决了在大多数极端耀斑事件期间能量如何在太阳上产生、释放和传输的根本问题。这项研究有助于更好地理解太阳高能粒子的机制及其影响，以及发展先进的预测能力。该项目涉及NJIT和科罗拉多大学的学生，他们将回答有关太阳耀斑能量产生和释放的基本物理问题。学生的结果将在专业会议和暑期项目以及大学学生活动中公布，从而促进STEM教育以及环境和空间研究。最近的观测和模拟结果表明，认为冲激阶段初级能量释放以高能电子束形式释放的太阳耀斑标准模型，不能解释太阳大气中观测到的影响和耀斑动力学。因此，有必要考虑能量释放和传输的其他机制，如质子束和电子-质子混合(中性)束。利用目前可用的计算模型和多仪器数据，该团队进行了全面的调查，并得出了脉冲阶段耀斑等离子体和加速粒子的性质。项目的具体任务是：(1)对耀斑发射、光谱和磁场数据进行多仪器定量分析；(2)通过进行辐射流体动力学模拟，模拟太阳大气层对各种能量释放通道(包括电子、质子和中性束，具有不同的能量通量和热通量)的动态响应；(3)利用耀斑动力学模型和辐射程序，分析各种能量释放通道的发射和光谱特性；(4)通过将模型特性与数据分析结果进行比较，得出冲激阶段耀斑能量释放的特性。该项目的研究和EPO议程支持AGS部门在发现、学习、多样性和跨学科研究方面的战略目标。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

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.