The Mechanism of the Solar Dynamo Governing Space Climate and Space Weather

太阳磁活动的长期和短期变化深刻地影响着地球上的空间天气和空间气候。过去的太阳活动显示了延长的极小时期，这仍然不是很好的理解。该项目将解决与太阳活动中最大极小的原因和特征有关的问题，太阳活动的特征在这些时期是如何变化的，以及这些变化是否可以模拟/预测。该方法结合了对太阳黑子数量的观测、同位素时间序列、机器学习技术和数值建模。这一结果将限制太阳能发电机在太阳上产生变化的磁场，从而导致太空天气。更广泛的影响将是提高我们对影响我们的地面、空中和天基技术系统的空间气候和空间天气的了解。这个项目支持一名早期的职业研究人员。首要的科学问题是破译太阳磁活动在时间和空间域的短期和长期行为背后的物理基础，并约束太阳发电机模型。直接和间接太阳活动指数，如太阳黑子以及10Be和14C同位素在年度和年代际分辨率的记录，将与机器学习技术和数值模拟相结合，用于重建过去11 000年中覆盖全新世的年度太阳黑子数。预期的结果包括：更好地描述过去太阳活动极小期之前、期间和之后的太阳周期长度；更好地理解太阳极小期和极大期的性质和发生特征；以及对太阳发电机模型的观测限制，以破译导致观测到的太阳活动变化的潜在物理机制。这一奖项反映了美国国家科学基金会的法定使命，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。

Long-term and short-term variations in the magnetic activity of the sun profoundly influence space weather on Earth and space climate. Past solar activity shows periods of extended minima, which are still not well understood. This project will address questions related to the cause and characteristics of grand minima in solar activity, how the character of solar activity changes during these periods, and whether these changes can be modeled/predicted. The methodology uses a combination of observations of sunspot numbers, isotope time series, machine learning techniques, and numerical modeling. The results will provide constraints on the solar dynamo that generates the changing magnetic fields on the sun, which causes space weather. The broader impacts will be to improve our understanding of our space climate and space weather that affect our ground-, air- and space-based technological systems. This project supports an early career researcher.The overarching scientific question is to decipher the physics underlying short- and long-term behavior of solar magnetic activity both in temporal and spatial domains, and to constrain the solar dynamo model. Direct and indirect solar activity indices, such as sunspots and 10Be and 14C isotope records at annual and decadal resolutions, combined with machine learning techniques and numerical simulations, will be used to reconstruct annual sunspot numbers throughout the past 11,000 years covering the Holocene. The expected results include better characterization of the length of the solar cycle before, during, and after past grand solar minima; improved understanding of the nature and occurrence characteristics of grand minima and maxima; and observational constraints on solar dynamo models to decipher the underlying physical mechanisms that lead to the observed variations in solar activity.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.