Study of the Solar Dynamics and its Evolution During Cycle 23 Based on an Improved Mode Fitting of a Solar Cycle Worth of Global Oscillation Network Group (GONG) Observations

首席调查员的目标是推断太阳内部自转的性质及其在第23太阳周期期间的演变，以便对太阳发电机模型提供关键的观测约束。他计划使用一组改进的模式频率，这组模式频率来自近13年的全球振荡网络组(GONG)观测。他将使用一种根据过去航天器观测开发的最先进的方法来拟合不同持续时间的时间序列，然后反转得到的模式集，以获得改进的模式特性。国际和平研究所指出，这一努力是及时的，因为现有的龚氏数据拟合方法是在近20年前开发的，并不是最优的。他预计，他的新拟合技术将是卓越的，并将改善龚氏数据的模式特征。作者指出，将这项技术应用于太阳球谐系数的时间序列，将大大改善太阳内部结构、动力学和演化的评估。这项工作将增加NSF资助的太阳球谐系数时间序列的科学回报，并将有助于解决有关太阳可变性的关键科学问题。PI的派生模式特性(频率、线宽、不对称性等)将免费提供给研究界用于其他科学研究。新的拟合方法将提供给GONG项目人员，以便他们在认为合适的情况下将其整合到他们的标准数据简化过程中。这项工作的结果还将补充对旧的天基数据集的现有分析，将对使用相同方法拟合的这些独立数据集提供独特的交叉验证，并将使最近放置在轨道上的新太阳仪器能够对第24太阳周期数据应用新的最先进的分析技术。

The Principal Investigator's objective is to infer the properties of internal solar rotation and its evolution during Solar Cycle 23, in order to provide key observational constraints on solar dynamo models. He plans to use an improved set of mode frequencies derived from nearly 13 years of Global Oscillation Network Group (GONG) observations. He will fit time series of various durations using a state-of-the-art methodology developed from past spacecraft observations, and then invert the resulting mode sets to obtain improved mode characteristics. The PI notes that this effort is timely, since the existing GONG data-fitting methodology was developed nearly 20 years ago and is not optimal. He expects his new fitting technique to be superior and to result in improved mode characteristics for GONG data. The proposer notes that the application of this technique to time series of GONG spherical harmonics coefficients will result in substantially improvements to assessments of solar internal structure, dynamics, and evolution.This work will increase the scientific return of the NSF-funded GONG project and will help address key scientific questions about solar variability. The PI's derived mode characteristics (frequency, line-width, asymmetry, and so forth) will be made freely available to the research community for additional scientific studies. The new fitting methodology will be provided to GONG project personnel, to allow them to integrate it into their standard data reduction process if deemed appropriate. The results from this effort also will complement existing analyses of older space-based data sets, will provide a unique cross-validation of these independent data sets fitted using the same methodology, and will allow the application of new state-of-the-art analysis techniques to Solar Cycle 24 data to be obtained by new solar instruments recently placed in orbit.