SunRISE - Application of Spectral Synthesis to the Study of Solar Visible, UV, EUV and Infrared Variability

研究人员将努力了解太阳辐射变化的物理起源。主要工作是利用太阳大气的半经验模型来表示太阳表面的特征，并在发现差异时重新定义模型。然后，研究人员将确定表面特征的分布对辐照度的影响，并将这些信息与光谱合成线和宽光谱带结合起来，从而计算出太阳特定状态的光谱和总辐照度。最终，研究人员试图确定未来最有效的测量方法，以便利用太阳光谱中的基本冗余。RISE计划的目的是提高对极紫外（EUV）、紫外（UV）、可见和红外辐射输出变化的现在、过去和未来的物理理解。在实际意义上，光谱综合使人们了解在没有适当精度的直接测量的情况下，使用替代物（也称为代理）来估计总辐照度和光谱辐照度的可靠性。利用太阳光谱的自然冗余性和相干性可以产生更有效的测量和分析程序。研究人员先前的工作说明了斑块和网络的演化和空间分布（即磁通量出现）在确定辐照度的详细时间变异性方面的重要性。这项工作还揭示了连续体强度变化对光球深处结构的敏感性。对太阳和气候变化之间在超过十年的时间尺度上存在联系的持续推测提出了一个重要的问题，即由于线和连续体的变异性，太阳光谱的颜色发生了变化。对太阳总辐照度和太阳辐射光谱形状的准确理论估计对气候研究至关重要。

The investigators will work to understand the physical origins of solar radiative variability. The main effort is to utilize semi-empirical models of the solar atmosphere to represent features on the solar surface and, where discrepancies are discovered, redefine the models. The investigators will then determine the effect of the distribution of surface features on irradiance and combine the information with spectral synthesis lines and broad spectral bands so as to compute spectral and total irradiance for a particular state of the Sun. Ultimately, the investigators seek to determine the most efficient measurements to make in the future in order to take advantage of the basic redundancy in the solar spectrum. The aim of the RISE program is to improve physical understanding of present, past, and future radiative output variations in the extreme ultraviolet (EUV), ultraviolet (UV), visible and infrared. In a practical sense, spectrum synthesis gives insight into the reliability of the use of surrogates (also known as proxies) to estimate total and spectral irradiance in the absence of direct measurements of appropriate accuracy. This exploitation of the natural redundancy and coherence in the solar spectrum can lead to more efficient measurement and analysis programs. Previous work of the investigators illustrated the importance of the evolution and spatial distribution of both plage and network (i.e. magnetic flux emergence) in determining the detailed time variability of irradiance. This work also revealed the sensitivity of the continuum intensity variation to structures deeper in the photosphere. The continuing speculation of a link between solar and climate variability on timescales longer than a decade raises the important issue of changes in the color of the solar spectrum due to variability of lines and continuum. An accurate theoretical estimate of the total solar irradiance and the shape of the solar radiation spectrum are essential to climate studies.