论文标题
活动区域周围的流量对南北热震的贡献
Contribution of flows around active regions to the north-south helioseismic travel-time measurements
论文作者
论文摘要
语境。在当地的热疗学中，声波的旅行时间沿着同一子午线在相反的方向传播，告知我们沿南北方向的水平流动。南北热震旅行时的纵向平均值随黑子周期而变化。目标。我们的目的是研究流入对太阳能周期变化的太阳活性区域的贡献。方法。为此，我们确定了从SDO/HMI连续图像中颗粒的相关跟踪获得的水平流图中活跃区域的局部流。我们计算使用3D敏感性内核引起的前进旅行时间扰动。为了与观测值进行比较，我们平均这些向前模型的旅行时间扰动在经度和时间上的时间与测量的旅行时间相同。结果。向前模型的方法表明，与活动区域相关的流入可能仅占南北旅行时间测量中太阳能周期变化的一小部分。结论。由活跃区域周围的大规模流入引起的旅行时间扰动并不能完全解释在子午循环的Heliose震荡测量中看到的太阳能周期变化。 关键词：太阳：活动 - 太阳：热学学
Context. In local helioseismology, the travel times of acoustic waves propagating in opposite directions along the same meridian inform us about horizontal flows in the north-south direction. The longitudinal averages of the north-south helioseismic travel-time shifts vary with the sunspot cycle. Aims. We aim to study the contribution of inflows into solar active regions to this solar-cycle variation. Methods. To do so, we identify the local flows around active regions in the horizontal flow maps obtained from correlation tracking of granulation in SDO/HMI continuum images. We compute the forward-modeled travel-time perturbations caused by these inflows using 3D sensitivity kernels. In order to compare with the observations, we average these forward-modeled travel-time perturbations over longitude and time in the same way as the measured travel times. Results. The forward-modeling approach shows that the inflows associated with active regions may account for only a fraction of the solar-cycle variations in the north-south travel-time measurements. Conclusions. The travel-time perturbations caused by the large-scale inflows surrounding the active regions do not explain in full the solar-cycle variations seen in the helioseismic measurements of the meridional circulation. Keywords: Sun: activity -- Sun: helioseismology
