Models of solar total and spectral irradiance variability of relevance for climate studies

与气候研究相关的太阳总辐照度和光谱辐照度变化模型

• 批准号: 5453814
• 负责人: Professor Dr. Sami K. Solanki
• 金额: --
• 依托单位: Max-Planck-Institut für Sonnensystemforschung (MPS)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2005
• 资助国家: 德国
• 起止时间: 2004-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5453814?language=en
• 关键词: Models; solar; total; spectral; irradiance

The influence of the Sun on climate is one of the major unknowns in the debate on global warming and on the causes of past climate changes. Although the evidence for solar influence on climate is growing, the origin of solar variability and the processes by which the variable solar input affects climate change are not well understood. A prime solar quantity for the Earth’s climate is solar total and spectral irradiance. Measurements of solar irradiance have revealed variations at all the sampled time scales from minutes to decades. Unfortunately, the measured irradiance time series is too short to work out the precise connection with climate change on Earth and has to be extended back in time with the help of suitable models. One important task of models is to identify the causes of the observed irradiance variations. We propose to build upon our previous work and rigorously test the hypothesis that solar irradiance variations are caused by the evolution of the surface magnetic field through the use of numerical simulations of the dynamic 3-D structure of the Sun’s magnetised atmosphere. Another major aim of the models is to reconstruct irradiance over time scales longer than sampled by direct observations. Here the main controversy surrounds the magnitude of the possible secular change of solar irradiance. We propose to use historic photographs of the Sun to determine by how much it has brightened in the 20th century. Finally, one of the main challenges to models is to predict future irradiance variations. We propose to employ a promising parameter, the tilt angles of sunspot groups to predict the level of solar activity and from that irradiance in the future.

太阳对气候的影响是关于全球变暖和过去气候变化原因的辩论中的主要未知数之一。虽然太阳对气候影响的证据越来越多，但太阳变率的起源和太阳输入变量影响气候变化的过程还没有得到很好的理解。太阳总辐照度和光谱辐照度是反映地球气候的一个主要太阳量。对太阳辐照度的测量揭示了从几分钟到几十年的所有采样时间尺度上的变化。不幸的是，测量到的辐照度时间序列太短，无法计算出与地球气候变化的精确联系，必须在合适模型的帮助下将其延长到过去。模型的一个重要任务是确定观测到的辐照度变化的原因。我们建议建立在我们以前的工作，并严格测试太阳辐照度的变化是由表面磁场的演变，通过使用的动态3-D结构的太阳的磁化大气的数值模拟的假设。模型的另一个主要目的是重建辐照度的时间尺度比直接观测采样。这里的主要争议围绕着太阳辐照度可能的长期变化的大小。我们建议使用太阳的历史照片来确定它在世纪的亮度。最后，模型面临的主要挑战之一是预测未来的辐照度变化。我们建议采用一个有前途的参数，太阳黑子群的倾斜角来预测太阳活动的水平，并从未来的辐照度。