UNDERSTANDING THE DYNAMICAL SOLAR ATMOSPHERE

在这一建议中，我们的目标是研究与太阳大气中经常发生的动力学过程有关的各个方面，这些过程仍然没有被理解。太阳物理学在观测我们星星的外层大气方面正经历一个黄金时代。在过去的几年里，已经发射了一系列空间任务来详细观察太阳大气层。即将到来的使命，太阳轨道器，是欧空局的一颗主要卫星，将于2018年发射，致力于研究日光层的内部，太阳系所在的气泡不断受到太阳事件的影响。其中一些事件与空间天气有关，即对地球大气层外层产生重大影响，对卫星、载人航天飞行和通信等造成重大影响。磁重联被认为是主要的物理效应。我们的目标是利用现有的卫星测量耀斑超拱廊的观测特征，这是一个发生强烈加热（超过一千万度）的区域。我们将研究在这个地区发挥大规模的3-D数值模拟的物理过程。我们将研究如何在太阳耀斑重联区的不稳定性可以产生超拱廊下降流，并比较模拟结果与观测。我们还打算研究太阳过渡区，即光球层和日冕之间的一层薄薄的大气层。这一区域非常活跃，我们的目标是研究，通过改进模型，如果非平衡效应可以解释来自这一层的强烈排放，并通过当前的任务观察到。我们还将研究非平衡效应在解释观测太阳过渡区的太阳轨道器仪器（SPICE）的观测结果中的重要性。我们还将使用新一代X射线仪器MaGIXS研究太阳活动区的高温发射动力学，该仪器将于2018年在探空火箭上飞行。MaGIXS将提供新的测量方法，帮助我们了解哪些物理过程导致活动区等离子体加热到300万度，这是过去40年来一直争论不休的问题。我们还打算继续提供最基本的原子数据，用于解释当前和未来太阳任务的观测结果。我们的小组一直在这一领域处于领先地位，不断更新CHIANTI原子数据库，现在也广泛用于天体物理学应用。最后，我们将向公众和学校宣传我们的工作，特别是通过太阳|Trek项目。

Within this proposal we aim to study various aspects related to dynamical processes that frequently occur in the solar atmosphere, and that are still not understood. Solar physics is now experiencing a golden age in terms of observations of the outer atmosphere of our star. In the past few years, a suite of space missions has been launched to observe the solar atmosphere in great detail.An upcoming mission, Solar Orbiter, is a major ESA satellite to be launched in 2018 and devoted to the study of the inner parts of the heliosphere, the bubble where our solar system resides that is constantly modified by events on the Sun. Some of these events have relevance to space weather, i.e. affect significantly the outer layers of the Earth atmosphere, causing significant effects on satellites, human space flight and communication, for example.Solar flares are massive releases of energy into the heliosphere in a short period of time. It is thought that magnetic reconnection is the main physical effect. We aim to measure, using current satellites, the observational signatures of the flare supra-arcade, a region where strong heating (to more than ten million degrees) occurs. We will investigate the physical processes at play in this region with large-scale 3-D numerical simulations. We will study how instabilities in the solar-flare reconnection region can produce supra-arcade downflows, and compare the results of the simulations with observations. We also aim to study the solar transition region, a thin layer of the atmosphere between the photosphere and corona of the Sun. This region is very dynamic, and we aim to study, with improvements in the models, if non-equilibrium effects can explain the strong emission that is coming from this layer and is observed by current missions. We will also study the importance of non-equilibrium effects in interpreting the observations of one of the Solar Orbiter instruments (SPICE), that will observe the solar transition region.We shall also study the dynamics of the high-temperature emission in solar active regions with a new-generation X-ray instrument, MaGIXS, which will be flown in 2018 on a sounding rocket. MaGIXS will provide novel measurements that will help us to understand which physical processes are responsible in heating the active region plasma to 3 million degrees, an issue that has been much debated over the past 40 years.We also aim to continue to provide the most fundamental atomic data for the interpretation of the observations of current and future solar missions. Our group has been leading this field by continuously updating the CHIANTI atomic database, now also widely used for astrophysical applications.Finally, we shall communicate our work to the public and to schools, in particular through the Sun|trek project.