Evidence for coherent spicule oscillations from correcting Hinode/SOT Ca ii H in the south-east limb of the Sun
Evidence for coherent spicule oscillations from correcting Hinode/SOT Ca ii H in the south-east limb of the Sun
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DOI：
10.1093/mnras/stx300
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发表时间：
2017-02
影响因子：
4.8
通讯作者：
A. A. Maralani-A.;E. Tavabi;A. Ajabshirizadeh
中科院分区：
文献类型：
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作者：
A. A. Maralani-A.;E. Tavabi;A. Ajabshirizadeh
加热色球层，日冕，太阳风由于光球波动的波动理论得到加强的存在观察到的波相干的过渡区（TR）。利用太阳光学望远镜（SOT）研究了日珥强度振荡的相干性。我们使用了2015年4月3日获得的Ca II H线的Hinode/SOT东南区域附近的时间序列，并将去卷积程序应用于骨针，以说明我们的恢复方法如何有效地作用于骨针等精细结构。此外，还利用小波变换分析了日缘以上不同高度的强度振荡。然后，在两个特定高度测量振荡之间的相位差，以寻找相干振荡的证据。小波变换的结果显示，在2，4，5.5，和6.5分钟在四个不同的高度的主周期峰。发现相干水平高于75%的主导频率在5.5和8.5 mHz左右。测量的平均相速度为155-360 km s-1。我们发现，平均相速度随高度增加。结果表明，相干波携带进入日冕和日光层的能量通量可能比之前仅基于恒定速度的估计大几倍。我们提供了令人信服的证据向上传播的相干波的存在。
Wave theories of heating the chromosphere, corona, and solar wind due to photospheric fluctuations are strengthened by the existence of observed wave coherency up to the transition region (TR). The coherency of solar spicules' intensity oscillations was explored using the Solar Optical Telescope (SOT) on the Hinode spacecraft with a height increase above the solar limb in active region (AR). We used time sequences near the southeast region from the Hinode/SOT in Ca II H line obtained on April 3, 2015 and applied the de-convolution procedure to the spicule in order to illustrate how effectively our restoration method works on fine structures such as spicules. Moreover, the intensity oscillations at different heights above the solar limb were analysed through wavelet transforms. Afterwards, the phase difference was measured among oscillations at two certain heights in search of evidence for coherent oscillations. The results of wavelet transformations revealed dominant period peaks in 2, 4, 5.5, and 6.5 min at four separate heights. The dominant frequencies for coherency level higher than 75 percent was found to be around 5.5 and 8.5 mHz. Mean phase speeds of 155-360 km s-1 were measured. We found that the mean phase speeds increased with height. The results suggest that the energy flux carried by coherent waves into the corona and heliosphere may be several times larger than previous estimates that were based solely on constant velocities. We provide compelling evidence for the existence of upwardly propagating coherent waves.