标题： 频率高于声学截止频率的太阳振荡的变化的纬度依赖性 显示英文标题

标题： Latitudinal dependence of variations in the frequencies of solar oscillations above the acoustic cut-off

摘要： 在高于声学截止频率的高频区域，太阳功率谱中可见类似峰值的结构。 被称为伪模态，它们的频率已被证明与太阳磁活动呈反相变化。 在本研究中，我们确定了这些频率在太阳表面的时间变化，旨在识别伪模态频率偏移的任何潜在纬度依赖性。 我们使用了近22年的空间分辨GONG数据，适用于所有方位阶数$\textit{m}$，以及谐波阶数 0$\leq$$\textit{l}$ $\leq$ 200，并使用重采样周期图方法确定了偏移量。 周期图实现是从重叠的连续216天长的时间段中创建的，并裁剪为5600-6800$\mu$Hz。 然后反复在这些实现之间生成互相关函数，以识别频率的变化和不确定性。 我们根据每种模式的纬度敏感性进行了分类，并利用这种分类为不同的纬度带(15$^\circ$和5$^\circ$大小)生成平均频率偏移，这些偏移与磁性代理、$F_{\mathrm{10.7}}$指数和GONG星图进行了比较。 在不同纬度之间的伪模式偏移中发现了形态差异，这在太阳活动达到最大值的上升阶段最为明显，此时偏移达到最小值。 在所有纬度上，偏移行为与活动代理呈强负相关。 此外，观察到了短于11年周期的周期性。 使用小波分析在所有纬度上识别出了4年的周期性。 显示英文摘要

摘要： At high frequencies beyond the acoustic cut-off, a peak-like structure is visible in the solar power spectrum. Known as the pseudo-modes, their frequencies have been shown to vary in anti-phase with solar magnetic activity. In this work, we determined temporal variations in these frequencies across the solar disc, with the aim of identifying any potential latitudinal dependence of pseudo-mode frequency shifts. We utilised nearly 22 years of spatially resolved GONG data for all azimuthal orders, $\textit{m}$, for harmonic degrees 0 $\leq$ $\textit{l}$ $\leq$ 200, and determined shifts using the resampled periodogram method. Periodogram realisations were created from overlapping, successive 216d-long segments in time, and cropped to 5600-6800$\mu$Hz. Cross-correlation functions were then repeatedly generated between these realisations to identify any variation in frequency and the uncertainty. We categorised each mode by its latitudinal sensitivity and used this categorisation to produce average frequency shifts for different latitude bands (15$^\circ$ and 5$^\circ$ in size) which were compared to magnetic proxies, the $F_{\mathrm{10.7}}$ index and GONG synoptic maps. Morphological differences in the pseudo-mode shifts between different latitudes were found, which were most pronounced during the rise to solar maximum where shifts reach their minimum values. At all latitudes, shift behaviour was strongly in anti-correlation with the activity proxy. Additionally, periodicities shorter than the 11-year cycle were observed. Wavelet analysis was used to identify a periodicity of four years at all latitudes.