Unexpected solar-cycle variation of acoustic mode power in Sun-as-a-star observations
Unexpected solar-cycle variation of acoustic mode power in Sun-as-a-star observations
复制标题
太阳恒星观测中声模功率的意外太阳周期变化
DOI：
10.1093/mnras/stac1534
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发表时间：
2022
影响因子：
4.8
通讯作者：
Howe R
中科院分区：
文献类型：
--
作者：
Howe R
我们通过查看伯明翰太阳振荡网络 45 年观测的分档功率谱来检查低度日震模式中功率的太阳周期变化，这提供了比峰值拟合获得的模式功率更可靠的估计。 5 分钟波段内声波模式功率的太阳周期变化清晰可见。不同寻常的是，尽管第 24 周期的表面磁活动明显弱于第 23 周期，但两个周期在太阳活动极大期时模式功率的减少非常相似，这表明模式功率与磁活动之间的关系比之前认为的更为复杂。这与模态频率形成鲜明对比，模态频率与活动具有很强的相关性，不同太阳周期的响应只有细微的差异。
We examine the solar-cycle variation of the power in the low-degree helioseismic modes by looking at binned power spectra from 45 yr of observations with the Birmingham Solar Oscillations Network, which provides a more robust estimate of the mode power than that obtained by peak fitting. The solar-cycle variation of acoustic mode power in the 5-min band is clearly seen. Unusually, even though Cycle 24 was substantially weaker in terms of surface magnetic activity than Cycle 23, the reduction in mode power at solar maximum is very similar for the two cycles, suggesting that the relationship between mode power and magnetic activity is more complex than has previously been thought. This is in contrast to the mode frequencies, which show a strong correlation with activity with only subtle differences in the response across different solar cycles.