RUI: An Investigation of the Solar Torsional Oscillations

这所本科院校的研究人员将研究驱动太阳扭转振荡的机制。旋转扰动表现出一种与时间相关的模式，将其与太阳的磁活动周期联系起来。将扭转模式与经向流和磁场的周期相关模式进行比较，表明它实际上是由三种独立的现象组成的，每一种现象都是科里奥利力的结果。这三个特征是：(1)在极场反转时，与向极经向流动相关的极自旋上升到极向下气流；(2)一个与经向气流相关的强切变迁移区，到一个覆盖在环面场带上的下降气流，产生了周期的活动区；(3)由于赤道的上升气流为向极地方向的经向气流提供补给而导致的赤道减速。首席研究员和学生们将通过分析威尔森山自1986年以来两条光谱线的数据，以及GONG和SOHO项目的数据，来检验这些和其他情景。本研究将探讨扭转模式的纵向和径向结构，并将其与子午运动和磁场模式的结构进行比较。研究人员还将研究用来揭示这种模式的方法，并探讨预测太阳活动周期的可能性。

The investigators at this undergraduate institution will study the mechanisms that drive solar torsional oscillations. The rotational perturbation exhibits a time-dependent pattern which links it to the Sun's magnetic activity cycle. Comparisons of the torsional pattern with the cycle-related patterns of meridional flow and magnetic field suggest that it is actually made up of three separate phenomena, and that each is the result of Coriolis forces. These three are: (1) a polar spin-up associated with poleward meridional flow to a downdraft at the poles at the time of polar field reversal; (2) a migrating zone of enhanced shear associated with meridional flows to a downdraft overlying the toroidal field band that gives rise to the active regions of the cycle; and (3) an equatorial slowing due to an updraft at the equator that feeds a poleward meridional flow. The principal investigator and students will examine these and other scenarios that have been proposed through the analysis of data taken in two spectral lines at Mount Wilson since 1986 and with data taken in the GONG and SOHO programs. This investigation will probe the torsional pattern's longitudinal and radial structure, and compare it with the structures in the patterns of meridional motion and magnetic field. The investigators will also examine the methods used to reveal the pattern and address the possibility of making solar cycle predictions.