论文标题
在锣++环形流量图中观察到的太阳罗斯比波
Solar Rossby waves observed in GONG++ ring-diagram flow maps
论文作者
论文摘要
上下文：直到最近在Helioseimsic和磁成像仪（HMI）和米歇尔森多普勒成像仪（MDI）图中，太阳能部门rossby波才被明确鉴定出来。到目前为止，这尚未使用具有不同噪声属性的全球振荡网络组（GONG）地面观测值。 目的：我们利用17年的锣++数据来使用环形三图Heliosesology来识别和表征太阳罗斯比波。我们直接与HMI Ring-Diagram分析进行比较。 方法：在表面前2 mm内获得radial涡度的地图，持续17年的锣++。对系统效应进行了纠正，包括与$ b_0 $角有关的年度周期性。然后，我们计算共旋转框架中流的径向涡度的傅立叶成分。我们对时间重叠的HMI数据进行相同的分析。 结果：我们发现，太阳能Rossby浪潮在Azimuthal订单之间具有$ M = 3 $和$ M = 15 $之间的Azimuthal订单的Gong ++部门功率谱。锣++的测量模式特性（频率，寿命和振幅）与2010年至2018年重叠期的HMI测量值一致。对于较高的$ m $模式，振幅和频率在两个sigmas中达成共识。锣++功率谱中模式的信噪比与HMI相当，价格为$ 8 \ le m \ le11 $，但对于其他模式，较低的倍数较低。 结论：Gong ++数据提供了一个长而均匀的数据集，以研究2001年的太阳能全球尺度Rossby波。
Context: Solar sectoral Rossby waves have only recently been unambiguously identified in Helioseimsic and Magnetic Imager (HMI) and Michelson Doppler Imager (MDI) maps of flows near the solar surface. So far this has not been done with the Global Oscillation Network Group (GONG) ground-based observations, which have different noise properties. Aims: We utilize 17 years of GONG++ data, to identify and characterize solar Rossby waves using ring-diagram helioseismology. We compare directly with HMI ring-diagram analysis. Methods: Maps of the radial vorticity are obtained for flows within the top 2 Mm of the surface for 17 years of GONG++. The data is corrected for systematic effects including the annual periodicity related to the $B_0$ angle. We then compute the Fourier components of the radial vorticity of the flows in the co-rotating frame. We perform the same analysis on the HMI data that overlap in time. Results: We find that the solar Rossby waves have measurable amplitudes in the GONG++ sectoral power spectra for azimuthal orders between $m=3$ and $m=15$. The measured mode characteristics (frequencies, lifetimes and amplitudes) from GONG++ are consistent with the HMI measurements in the overlap period from 2010 to 2018 for $m\le9$. For higher-$m$ modes the amplitudes and frequencies agree within two sigmas. The signal-to-noise ratio of modes in GONG++ power spectra is comparable to HMI for $8\le m\le11$, but is lower by a factor of two for other modes. Conclusions: The GONG++ data provide a long and uniform data set to study solar global-scale Rossby waves from 2001.
