Presented here is a review of present knowledge of the long-term behavior of solar activity on a multi-millennial timescale, as reconstructed using the indirect proxy method. The concept of solar activity is discussed along with an overview of the special indices used to quantify different aspects of variable solar activity, with special emphasis upon sunspot number. Over long timescales, quantitative information about past solar activity can only be obtained using a method based upon indirect proxies, such as the cosmogenic isotopes \(^{14}\)C and \(^{10}\)Be in natural stratified archives (e.g., tree rings or ice cores). We give an historical overview of the development of the proxy-based method for past solar-activity reconstruction over millennia, as well as a description of the modern state. Special attention is paid to the verification and cross-calibration of reconstructions. It is argued that this method of cosmogenic isotopes makes a solid basis for studies of solar variability in the past on a long timescale (centuries to millennia) during the Holocene. A separate section is devoted to reconstructions of strong solar energetic-particle (SEP) events in the past, that suggest that the present-day average SEP flux is broadly consistent with estimates on longer timescales, and that the occurrence of extra-strong events is unlikely. Finally, the main features of the long-term evolution of solar magnetic activity, including the statistics of grand minima and maxima occurrence, are summarized and their possible implications, especially for solar/stellar dynamo theory, are discussed.

这里介绍了对太阳活动在数千年时间尺度上的长期行为的现有知识的回顾，这些知识是使用间接代理方法重建的。讨论了太阳活动的概念，并概述了用于量化可变太阳活动不同方面的特殊指数，特别强调了太阳黑子数。在很长的时间尺度上，有关过去太阳活动的定量信息只能使用基于间接代理的方法来获得，例如宇宙成因同位素\(^{14}\) C 和\(^{10}\)存在于自然分层档案中（例如，树木年轮或冰芯）。我们对过去数千年来基于代理的太阳活动重建方法的发展进行了历史概述，并对现代状态进行了描述。特别关注重建的验证和交叉校准。有人认为，这种宇宙成因同位素方法为全新世期间长期（几个世纪到几千年）太阳变率的研究奠定了坚实的基础。一个单独的部分致力于重建过去的强太阳高能粒子（SEP）事件，这表明目前的平均 SEP 通量与较长时间尺度的估计大致一致，并且超强事件的发生是不太可能。最后，总结了太阳磁活动长期演化的主要特征，包括极小值和极大值出现的统计，并讨论了它们可能的含义，特别是对太阳/恒星发电机理论的影响。